Publications by authors named "Elie Poulin"

47 Publications

Exploring the Microdiversity Within Marine Bacterial Taxa: Toward an Integrated Biogeography in the Southern Ocean.

Front Microbiol 2021 14;12:703792. Epub 2021 Jul 14.

Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile.

Most of the microbial biogeographic patterns in the oceans have been depicted at the whole community level, leaving out finer taxonomic resolution (i.e., microdiversity) that is crucial to conduct intra-population phylogeographic study, as commonly done for macroorganisms. Here, we present a new approach to unravel the bacterial phylogeographic patterns combining community-wide survey by 16S rRNA gene metabarcoding and intra-species resolution through the oligotyping method, allowing robust estimations of genetic and phylogeographic indices, and migration parameters. As a proof-of-concept, we focused on the bacterial genus across three distant biogeographic provinces of the Southern Ocean; maritime Antarctica, sub-Antarctic Islands, and Patagonia. Each targeted operational taxonomic units were characterized by a substantial intrapopulation microdiversity, and significant genetic differentiation and phylogeographic structure among the three provinces. Gene flow estimations among populations support the role of the Antarctic Polar Front as a biogeographic barrier to bacterial dispersal between Antarctic and sub-Antarctic provinces. Conversely, the Antarctic Circumpolar Current appears as the main driver of gene flow, connecting sub-Antarctic Islands with Patagonia and maritime Antarctica. Additionally, historical processes (drift and dispersal limitation) govern up to 86% of the spatial turnover among populations. Overall, our approach bridges the gap between microbial and macrobial ecology by revealing strong congruency with macroorganisms distribution patterns at the populational level, shaped by the same oceanographic structures and ecological processes.
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http://dx.doi.org/10.3389/fmicb.2021.703792DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8317501PMC
July 2021

Is the southern crab Halicarcinus planatus (Fabricius, 1775) the next invader of Antarctica?

Glob Chang Biol 2021 08 24;27(15):3487-3504. Epub 2021 May 24.

LEMAS-Laboratorio de Ecología de Macroalgas Antárticas y Sub antárticas, Universidad de Magallanes, Punta Arenas, Chile.

The potential for biological colonization of Antarctic shores is an increasingly important topic in the context of anthropogenic warming. Successful Antarctic invasions to date have been recorded exclusively from terrestrial habitats. While non-native marine species such as crabs, mussels and tunicates have already been reported from Antarctic coasts, none have as yet established there. Among the potential marine invaders of Antarctic shallow waters is Halicarcinus planatus (Fabricius, 1775), a crab with a circum-Subantarctic distribution and substantial larval dispersal capacity. An ovigerous female of this species was found in shallow waters of Deception Island, South Shetland Islands in 2010. A combination of physiological experiments and ecological modelling was used to assess the potential niche of H. planatus and estimate its future southward boundaries under climate change scenarios. We show that H. planatus has a minimum thermal limit of 1°C, and that its current distribution (assessed by sampling and niche modelling) is physiologically restricted to the Subantarctic region. While this species is presently unable to survive in Antarctica, future warming under both 'strong mitigation' and 'no mitigation' greenhouse gas emission scenarios will favour its niche expansion to the Western Antarctic Peninsula (WAP) by 2100. Future human activity also has potential to increase the probability of anthropogenic translocation of this species into Antarctic ecosystems.
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http://dx.doi.org/10.1111/gcb.15674DOI Listing
August 2021

Cross-species transmission of retroviruses among domestic and wild felids in human-occupied landscapes in Chile.

Evol Appl 2021 Apr 27;14(4):1070-1082. Epub 2021 Jan 27.

Instituto de Ecología y Biodiversidad (IEB) Santiago Chile.

Human transformation of natural habitats facilitates pathogen transmission between domestic and wild species. The guigna (), a small felid found in Chile, has experienced habitat loss and an increased probability of contact with domestic cats. Here, we describe the interspecific transmission of feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) between domestic cats and guignas and assess its correlation with human landscape perturbation. Blood and tissue samples from 102 free-ranging guignas and 262 domestic cats were collected and analyzed by PCR and sequencing. Guigna and domestic cat FeLV and FIV prevalence were very similar. Phylogenetic analysis showed guigna FeLV and FIV sequences are positioned within worldwide domestic cat virus clades with high nucleotide similarity. Guigna FeLV infection was significantly associated with fragmented landscapes with resident domestic cats. There was little evidence of clinical signs of disease in guignas. Our results contribute to the understanding of the implications of landscape perturbation and emerging diseases.
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http://dx.doi.org/10.1111/eva.13181DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8061269PMC
April 2021

Unveiling the unknown phylogenetic position of the scallop Austrochlamys natans and its implications for marine stewardship in the Magallanes Province.

Sci Rep 2021 Mar 31;11(1):7241. Epub 2021 Mar 31.

Laboratorio de Ecosistemas Marinos Antárticos Y Subantárticos, Universidad de Magallanes, Avenida Bulnes 01890, Punta Arenas, Chile.

Two species of scallop, Austrochlamys natans ("Ostión del Sur") and Zygochlamys patagonica ("Ostión patagonico") are presently exploited in the southern part of the Magallanes Province (MP). The lack of clarity in taxonomic identification and ecological aspects is generating both erroneous extraction statistics and an unperceived harvesting pressure on A. natans and Z. patagonica. We aim to discriminate these Magallanes scallops accurately, improve our understanding of their complex natural history and discuss possible implications for their management and conservation status, given the current fisheries statistics. To achieve these goals, we present a complete review of the historical identification of the Magallanes scallop and a multi-locus molecular phylogeny which allowed us to recover the phylogenetic position of A. natans. We sampled 54 individuals from five localities across the southern Pacific coast of the MP. We calculated the depth of the byssal notch (BND) and shell height (VH) ratio from morphological characters and conducted phylogenetic reconstructions with mitochondrial (12S and 16S) and nuclear markers (28S) using Bayesian and maximum likelihood analyses. Both morphology and molecular phylogeny identified two distinct entities, Z. patagonica and a distinct, highly divergent lineage that corresponds to A. natans. Our study provides integrative evidence to alert the current fishery management and the need for further conservation studies.
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http://dx.doi.org/10.1038/s41598-021-86492-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8012595PMC
March 2021

Molecular Survey of Parvoviruses and Mycoplasma spp. in Invasive American Mink (Neovison vison) from Southern Chile.

J Wildl Dis 2021 01;57(1):234-237

Departamento de Ciencias Biológicas y Biodiversidad, Universidad de Los Lagos, Avenida Fuchslocher 1305, Osorno, Chile.

Using PCR, we evaluated the presence of parvoviruses and Mycoplasma spp. in 123 American mink (Neovison vison), an introduced invasive carnivore in Chile. Our results showed all analyzed animals were negative for both pathogen groups. We cannot completely dismiss their presence, but if present, their prevalence should be lower than 2%.
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http://dx.doi.org/10.7589/JWD-D-20-00047DOI Listing
January 2021

Epidemiology and molecular characterization of Carnivore protoparvovirus-1 infection in the wild felid Leopardus guigna in Chile.

Transbound Emerg Dis 2020 Nov 25. Epub 2020 Nov 25.

Departamento de Ciencias Biológicas y Biodiversidad, Universidad de Los Lagos, Osorno, Chile.

Landscape anthropization has been identified as one of the main drivers of pathogen emergence worldwide, facilitating pathogen spillover between domestic species and wildlife. The present study investigated Carnivore protoparvovirus-1 infection using molecular methods in 98 free-ranging wild guignas (Leopardus guigna) and 262 co-occurring owned, free-roaming rural domestic cats. We also assessed landscape anthropization variables as potential drivers of infection. Protoparvovirus DNA was detected in guignas across their entire distribution range, with observed prevalence of 13.3% (real-time PCR) and 9% (conventional PCR) in guignas, and 6.1% (conventional PCR) in cats. Prevalence in guigna did not vary depending on age, sex, study area or landscape variables. Prevalence was higher in juvenile cats (16.7%) than in adults (4.4%). Molecular characterization of the virus by amplification and sequencing of almost the entire vp2 gene (1,746 bp) from one guigna and five domestic cats was achieved, showing genetic similarities to canine parvovirus 2c (CPV-2c) (one guigna and one cat), feline panleukopenia virus (FPV) (one cat), CPV-2 (no subtype identified) (two cats), CPV-2a (one cat). The CVP-2c-like sequence found in a guigna clustered together with domestic cat and dog CPV-2c sequences from South America, suggesting possible spillover from a domestic to a wild species as the origin of infection in guigna. No clinical signs of disease were found in PCR-positive animals except for a CPV-2c-infected guigna, which had haemorrhagic diarrhoea and died a few days after arrival at a wildlife rescue centre. Our findings reveal widespread presence of Carnivore protoparvovirus-1 across the guigna distribution in Chile and suggest that virus transmission potentially occurs from domestic to wild carnivores, causing severe disease and death in susceptible wild guignas.
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http://dx.doi.org/10.1111/tbed.13937DOI Listing
November 2020

Genome-wide analyses reveal drivers of penguin diversification.

Proc Natl Acad Sci U S A 2020 09 17;117(36):22303-22310. Epub 2020 Aug 17.

Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA 94720;

Penguins are the only extant family of flightless diving birds. They currently comprise at least 18 species, distributed from polar to tropical environments in the Southern Hemisphere. The history of their diversification and adaptation to these diverse environments remains controversial. We used 22 new genomes from 18 penguin species to reconstruct the order, timing, and location of their diversification, to track changes in their thermal niches through time, and to test for associated adaptation across the genome. Our results indicate that the penguin crown-group originated during the Miocene in New Zealand and Australia, not in Antarctica as previously thought, and that is the sister group to all other extant penguin species. We show that lineage diversification in penguins was largely driven by changing climatic conditions and by the opening of the Drake Passage and associated intensification of the Antarctic Circumpolar Current (ACC). Penguin species have introgressed throughout much of their evolutionary history, following the direction of the ACC, which might have promoted dispersal and admixture. Changes in thermal niches were accompanied by adaptations in genes that govern thermoregulation and oxygen metabolism. Estimates of ancestral effective population sizes ( ) confirm that penguins are sensitive to climate shifts, as represented by three different demographic trajectories in deeper time, the most common (in 11 of 18 penguin species) being an increased between 40 and 70 kya, followed by a precipitous decline during the Last Glacial Maximum. The latter effect is most likely a consequence of the overall decline in marine productivity following the last glaciation.
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http://dx.doi.org/10.1073/pnas.2006659117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7486704PMC
September 2020

Range-wide genetic structure in the thorn-tailed rayadito suggests limited gene flow towards peripheral populations.

Sci Rep 2020 06 10;10(1):9409. Epub 2020 Jun 10.

Instituto de Ecología y Biodiversidad, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile.

Understanding the population genetic consequences of habitat heterogeneity requires assessing whether patterns of gene flow correspond to landscape configuration. Studies of the genetic structure of populations are still scarce for Neotropical forest birds. We assessed range-wide genetic structure and contemporary gene flow in the thorn-tailed rayadito (Aphrastura spinicauda), a passerine bird inhabiting the temperate forests of South America. We used 12 microsatellite loci to genotype 582 individuals from eight localities across a large latitudinal range (30°S-56°S). Using population structure metrics, multivariate analyses, clustering algorithms, and Bayesian methods, we found evidence for moderately low regional genetic structure and reduced gene flow towards the range margins. Genetic differentiation increased with geographic distance, particularly in the southern part of the species' distribution where forests are continuously distributed. Populations in the north seem to experience limited gene flow likely due to forest discontinuity, and may comprise a demographically independent unit. The southernmost population, on the other hand, is genetically depauperate and different from all other populations. Different analytical approaches support the presence of three to five genetic clusters. We hypothesize that the genetic structure of the species follows a hierarchical clustered pattern.
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http://dx.doi.org/10.1038/s41598-020-66450-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7287099PMC
June 2020

Characterization of the Gut Microbiota of the Antarctic Heart Urchin (Spatangoida) .

Front Microbiol 2020 28;11:308. Epub 2020 Feb 28.

Laboratorio de Ecología Microbiana, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile.

is an irregular sea urchin species that inhabits shallow waters of South Georgia and South Shetlands Islands. As a deposit-feeder, nutrition relies on the ingestion of the surrounding sediment in which it lives barely burrowed. Despite the low complexity of its feeding habit, it harbors a long and twice-looped digestive tract suggesting that it may host a complex bacterial community. Here, we characterized the gut microbiota of specimens from two populations at the south of the King George Island in the West Antarctic Peninsula. Using a metabarcoding approach targeting the 16S rRNA gene, we characterized the microbiota composition and putative functional capacity, evaluating its differentiation among the gut content and the gut tissue in comparison with the external sediment. Additionally, we aimed to define a core gut microbiota between populations to identify potential keystone bacterial taxa. Our results show that the diversity and the composition of the microbiota, at both genetic and predicted functional levels, were mostly driven by the sample type, and to a lesser extent by the population location. Specific bacterial taxa, belonging mostly to and , were differently enriched in the gut content and the gut tissue, respectively. Predictive functional profiles revealed higher abundance of specific pathways, as the sulfur cycle in the gut content and the amino acid metabolism, in the gut tissue. Further, the definition of a core microbiota allowed to obtain evidence of specific localization of bacterial taxa and the identification of potential keystone taxa assigned to the and genera as potentially host selected. The ecological relevance of these keystone taxa in the host metabolism is discussed.
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http://dx.doi.org/10.3389/fmicb.2020.00308DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7058685PMC
February 2020

Global phylogeography and genetic diversity of the long-finned pilot whale Globicephala melas, with new data from the southeastern Pacific.

Sci Rep 2020 02 4;10(1):1769. Epub 2020 Feb 4.

Instituto de Ecología y Biodiversidad, Laboratorio de Ecología Molecular, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile.

The matrilineal long-finned pilot whale presents an antitropical distribution and is divided into two subspecies, one in the temperate seas of the Southern Hemisphere and the other restricted to the North Atlantic and Mediterranean. Until now, population genetic and phylogeographic studies have included localities of most of its Northern Hemisphere distribution, while only the southwestern Pacific has been sampled in the Southern Hemisphere. We add new genetic data from the southeastern Pacific to the published sequences. Low mitochondrial and nuclear diversity was encountered in this new area, as previously reported for other localities. Four haplotypes were found with only one new for the species. Fifteen haplotypes were detected in the global dataset, underlining the species' low diversity. As previously reported, the subspecies shared two haplotypes and presented a strong phylogeographic structure. The extant distribution of this species has been related to dispersal events during the Last Glacial Maximum. Using the genetic data and Approximate Bayesian Calculations, this study supports this historical biogeographic scenario. From a taxonomic perspective, even if genetic analyses do not support the subspecies category, this study endorses the incipient divergence process between hemispheres, thus maintaining their status and addressing them as Demographically Independent Populations is recommended.
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http://dx.doi.org/10.1038/s41598-020-58532-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7000830PMC
February 2020

Antibiotic resistance genes as landscape anthropization indicators: Using a wild felid as sentinel in Chile.

Sci Total Environ 2020 Feb 1;703:134900. Epub 2019 Nov 1.

Instituto de Ecología y Biodiversidad (IEB), Santiago, Chile; Departamento de Ciencias Biológicas y Biodiversidad, Universidad de Los Lagos, Osorno, Chile. Electronic address:

Antimicrobial resistance is a global emerging public health issue whose presence and impact in wildlife are widely unknown. Antimicrobial resistance genes (ARGs) are considered environmental contaminants, suitable to evaluate the degree of anthropic impact on wildlife and the environment. We used a wild felid, the guigna (Leopardus guigna), as a sentinel for the presence of ARGs in anthropized and pristine areas across their entire distribution range in Chile. We evaluated fecal samples from 51 wild guignas, collected between 2009 and 2018. Real-time PCR essays were employed to detect and quantify 22 selected ARGs in their fecal microbiome. All animals (100%) were positive for at least one ARG. The most prevalent ARG families were those that confer resistance to tetracycline (88.2%) and beta-lactamase (68.9%), with tet(Q) (60.8%), tet(W) (60.8%), and bla (66.7%) as the most prevalent ARGs. Multi-resistance profiles were observed in 43% of the guignas. Statistically significant differences were found between anthropized and pristine areas for tet(Q) (p = 0.014), tet(W) (p = 0.0037), tetracycline family (p = 0.027), multi-resistance profile prevalence (p = 0.043) and tet(W) quantification (p = 0.004). Two animals from anthropized landscapes were positive for mecA, a gene associated with Staphylococcus aureus and other staphylococci resistant to methicillin, while three animals from anthropized areas were positive for bla, that encodes class A extended-spectrum beta-lactamase. Both genes have been identified in bacteria causing relevant nosocomial infections worldwide. This is the first study on ARGs in wild felids from Chile and the first detection of mecA in South American wild felids. We observed an association between the degree of landscape anthropization and ARG prevalence, confirming that ARGs are important indicators of wildlife exposure to human activity/presence, with a widespread distribution.
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http://dx.doi.org/10.1016/j.scitotenv.2019.134900DOI Listing
February 2020

Taxonomic and systematic implications of the revision of the phylogenetic relations in the genus Ectinogonia Spinola 1837 (Coleoptera: Buprestidae) of Central Chile.

Zootaxa 2019 May 8;4603(1):zootaxa.4603.1.8. Epub 2019 May 8.

Instituto de Ecología y Biodiversidad, Facultad de Ciencias, Universidad de Chile.

Ectinogonia Spinola 1837 is composed of 22 species to date, but its taxonomic history has been complex and is still unresolved. The species of the Santiagan Province of Central Chile are particularly complex because they show important morphological variability and overlapping traits, making species identification and delimitation difficult. The main goal of the present study is to show the phylogenetic relationships among species of Ectinogonia of the Santiagan province and discuss the taxonomic and systematic implications of our findings. Phylogeny reconstructions as well as a haplotype network disclosed four groups, partially inconsistent with the traditional taxonomy. Actually, the two Ectinogonia speciosa subspecies (E. speciosa speciosa (Germain 1856) and E. speciosa oscuripennis Cobos 1954) belong to two distinct clades, which are not reciprocally monophyletic, meaning that Ectinogonia speciosa is polyphyletic. On the other hand, the two other clades each contain, two nominal species (E. buquetii (Spinola 1837) and E. vidali Moore Guerrero 2017, and E. isamarae Moore 1994 and E. speciosa oscuripennis Cobos 1954) without reciprocal haplotype sorting. These results suggest that: (1) E. speciosa oscuripennis should be raised to species level and (2) the following new synonymies are proposed: E. isamarae Moore 1994 is synonymised with E. oscuripennis Cobos 1954 and E. vidali Moore Guerrero 2017 is synonymised with E. buquetii (Spinola 1837).
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http://dx.doi.org/10.11646/zootaxa.4603.1.8DOI Listing
May 2019

Molecular and serological survey of carnivore pathogens in free-roaming domestic cats of rural communities in southern Chile.

J Vet Med Sci 2019 Dec 15;81(12):1740-1748. Epub 2019 Oct 15.

Institute of Ecology and Biodiversity (IEB), Las Palmeras 3425, Ñuñoa, Santiago, Chile.

Owned, free-roaming domestic cats are abundant in the Chilean countryside, having high probability of contact with wildlife and potentially participating as reservoirs of zoonotic pathogens. In the present study, 131 cats from two remote study areas (Valdivia and Chiloe Island) in southern Chile were analyzed for infection/exposure to eight pathogens. Serum samples from 112 cats were tested for antigens against feline leukemia virus (FeLV antigen-ELISA) and antibodies against feline immunodeficiency virus (FIV-ELISA) and canine distemper virus (CDV-serum neutralization), yielded occurrence of 8.9, 1.7 and 0.8% respectively. The presence of DNA of five vector-borne pathogens, piroplasmids, Ehrlichia spp., Anaplasma spp., Rickettsia spp. and Bartonella spp. was investigated in thirty cats. Overall observed occurrence was 6.6% (2/30) for both Anaplasma platys, and B. henselae, and 3.3% (1/30) for both Bartonella sp. and Theileria equi. Observed occurrence for all vector-borne pathogens in Valdivia area was significantly higher than in Chiloe Island (5/15 vs 0/15; P=0.04). Our results represent the first description of exposure to CDV and DNA detection of T. equi and A. platys in domestic cats in Chile. The results highlight the importance of performing pathogen screening in owned, free-roaming rural cats to evaluate their potential role as reservoirs of infection and vectors for disease transmission to wildlife.
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http://dx.doi.org/10.1292/jvms.19-0208DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6943315PMC
December 2019

More than the eye can see: Genomic insights into the drivers of genetic differentiation in Royal/Macaroni penguins across the Southern Ocean.

Mol Phylogenet Evol 2019 10 16;139:106563. Epub 2019 Jul 16.

Pontificia Universidad Católica de Chile, Facultad de Agronomía e Ingeniería Forestal, Departamento de Ecosistemas y Medio Ambiente, Vicuña Mackenna 4860, Macul, Santiago, Chile. Electronic address:

The study of systematics in wide-ranging seabirds can be challenging due to the vast geographic scales involved, as well as the possible discordance between molecular, morphological and behavioral data. In the Southern Ocean, macaroni penguins (Eudyptes chrysolophus) are distributed over a circumpolar range including populations in Antarctic and sub-Antarctic areas. Macquarie Island, in its relative isolation, is home to a closely related endemic taxon - the royal penguin (Eudyptes schlegeli), which is distinguishable from E. chrysolophus mainly by facial coloration. Although these sister taxa are widely accepted as representing distinct species based on morphological grounds, the extent of their genome-wide differentiation remains uncertain. In this study, we use genome-wide Single Nucleotide Polymorphisms to test genetic differentiation between these geographically isolated taxa and evaluate the main drivers of population structure among breeding colonies of macaroni/royal penguins. Genetic similarity observed between macaroni and royal penguins suggests they constitute a single evolutionary unit. Nevertheless, royal penguins exhibited a tendency to cluster only with macaroni individuals from Kerguelen Island, suggesting that dispersal occurs mainly between these neighboring colonies. A stepping stone model of differentiation of macaroni/royal populations was further supported by a strong pattern of isolation by distance detected across its whole distribution range, possibly driven by large geographic distances between colonies as well as natal philopatry. However, we also detected intraspecific genomic differentiation between Antarctic and sub-Antarctic populations of macaroni penguins, highlighting the role of environmental factors together with geographic distance in the processes of genetic differentiation between Antarctic and sub-Antarctic waters.
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http://dx.doi.org/10.1016/j.ympev.2019.106563DOI Listing
October 2019

Distribution of the genus (Crustacea, Copepoda, Calanoida, Centropagidae) at high latitudes in South America and the main Antarctic biogeographic regions.

Zookeys 2019 10;854:1-15. Epub 2019 Jun 10.

Laboratorio de Ecología Molecular, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile. Las Palmeras 3425, Ñuñoa, Santiago, Chile Instituto de Ecología y Biodiversidad Santiago Chile.

Copepods are present in numerous aquatic environments, playing key roles in food webs, and are thought to be useful indicators of environmental change. is a calanoid copepod genus distributed mainly in the Southern Hemisphere, with 14 species reported at higher southern latitudes in South America and Antarctica. We present an updated database of these 14 species of generated from a combination of three sources: 1) new field sampling data, 2) published records, and 3) Global Biodiversity Information Facility (GBIF), to provide a comprehensive description of the geographic distribution of the genus south of latitude 40°S in southern South America and the three main terrestrial biogeographic regions of Antarctica. The database includes 380 records, 62 from field sampling, 278 from the literature and 40 from GBIF. Southern South America, including the Falkland/Malvinas Islands, had the highest species richness and number of records (14 and 297, respectively), followed by the sub-Antarctic islands (5 and 34), South Orkney Islands (2 and 14), South Shetland Islands (1 and 23), Antarctic Peninsula (1 and 10) and finally continental Antarctica (1 and 2). Mrázek, 1901 is the only representative of the genus, and more widely the only terrestrial/freshwater invertebrate, currently reported from all three main biogeographic regions in Antarctica (sub-Antarctic islands, maritime and continental Antarctic). Future development of molecular systematic studies in this group should contribute to assessing the correspondence between morphological taxonomy and molecular evolutionary radiation.
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http://dx.doi.org/10.3897/zookeys.854.29614DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6579792PMC
June 2019

Antarctic and sub-Antarctic Nacella limpets reveal novel evolutionary characteristics of mitochondrial genomes in Patellogastropoda.

Mol Phylogenet Evol 2019 02 3;131:1-7. Epub 2018 Nov 3.

Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Casilla 567, Valdivia, Chile.

Mitochondrial genomes (mitogenomes) provide valuable phylogenetic information and genome-level characters that are useful in resolving evolutionary relationships within major lineages of gastropods. However, for more than one decade, these relationships and the phylogenetic position of Patellogastropoda have been inferred based on the genomic architecture as well as the nucleotide and protein sequences of a single representative, the limpet Lottia digitalis. This mitogenome exhibits extensive rearrangements and several repetitive units that may not represent universal features for Patellogastropoda. Here, we sequenced the complete mitogenomes of three Nacella limpets, providing new insights into the dynamics of gene order and phylogenetic relationships of Patellogastropoda. Comparative analyses revealed novel gene rearrangements in Gastropoda, characterised by two main translocations that affect the KARNI and the MYCWQ clusters in Nacella limpets. Our phylogenetic reconstructions using combined sequence datasets of 13 mitochondrial protein-coding genes and two rRNAs, recovered Patellogastropoda, and Gastropoda in general, as non-monophyletic. These findings could be related to the long-branch attraction tendency of these groups, and/or taxon sampling bias. In our novel mitogenome-based phylogenetic hypothesis, L. digitalis is placed in a sister position to Bivalvia and Heterobranchia, whereas Nacella limpets are placed sister to a clade containing Caenogastropoda + Neritimorpha and Vetigastropoda + Neomphalina.
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http://dx.doi.org/10.1016/j.ympev.2018.10.036DOI Listing
February 2019

Molecular and Serologic Survey of Pathogens in an Endangered Andean Cat ( Leopardus jacobita) of the High Andes of Bolivia.

J Wildl Dis 2019 01 20;55(1):242-245. Epub 2018 Aug 20.

1 Instituto de Ecología y Biodiversidad (IEB), Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Santiago, Chile.

The Andean cat ( Leopardus jacobita) is one of the most threatened and least known wild felids in the world. Using molecular and serologic tests, we screened a free-ranging Andean cat for 17 pathogens of conservation concern. Results suggested no evidence of infection or exposure. Whether pathogens are a threat for Andean cat populations remains currently unknown.
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http://dx.doi.org/10.7589/2018-05-136DOI Listing
January 2019

Correction to: Chinstrap penguin population genetic structure: one or more populations along the Southern Ocean?

BMC Evol Biol 2018 07 25;18(1):117. Epub 2018 Jul 25.

Departamento de Ecosistemas y Medio Ambiente, Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul, Santiago, Chile.

Correction to: BMC Evolutionary Biology (2018) 18:90 https://doi.org/10.1186/s12862-018-1207-0 .
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http://dx.doi.org/10.1186/s12862-018-1231-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6060512PMC
July 2018

Thorson's rule, life-history evolution, and diversification of benthic octopuses (Cephalopoda: Octopodoidea).

Evolution 2018 09 31;72(9):1829-1839. Epub 2018 Jul 31.

Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Santiago, Chile.

Here, we evaluate the so-called Thorson's rule, which posits that direct-development and larger eggs are favored toward the poles in marine organisms and whose validity been the subject of considerable debate in the literature, combining an expanded phenotypic dataset encompassing 60 species of benthic octopuses with a new molecular phylogeny. Phylogenetic reconstruction shows two clades: clade 1 including species of the families Eledonidae, Megaleledonidae, Bathypolypodidae, and Enteroctopodidae, and clade 2 including species of Octopodidae. Egg size, development mode, and all environmental variables exhibited phylogenetic signal, partly due to differences between the two clades: whereas most species in clade 1 inhabit cold and deep waters, exhibit large eggs and hatchling with holobenthic development, species from clade 2 inhabit tropical-temperate and shallow waters, evolved small eggs, and generally exhibit merobenthic development. Phylogenetic regressions show that egg size exhibits a conspicuous latitudinal cline, and that both egg size and development mode vary with water temperature. Additionally, analyses suggest that egg size is constrained by body size in lineages with holobenthic development. Taken together, results suggest that the variation in egg size and development mode across benthic octopuses is adaptive and associated with water temperature, supporting Thorson's rule in these organisms.
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http://dx.doi.org/10.1111/evo.13559DOI Listing
September 2018

Chinstrap penguin population genetic structure: one or more populations along the Southern Ocean?

BMC Evol Biol 2018 06 13;18(1):90. Epub 2018 Jun 13.

Departamento de Ecosistemas y Medio Ambiente, Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul, Santiago, Chile.

Background: Historical factors, demography, reproduction and dispersal are crucial in determining the genetic structure of seabirds. In the Antarctic marine environment, penguins are a major component of the avian biomass, dominant predators and important bioindicators of ecological change. Populations of chinstrap penguins have decreased in nearly all their breeding sites, and their range is expanding throughout the Antarctic Peninsula. Population genetic structure of this species has been studied in some colonies, but not between breeding colonies in the Antarctic Peninsula or at the species' easternmost breeding colony (Bouvetøya).

Results: Connectivity, sex-biased dispersal, diversity, genetic structure and demographic history were studied using 12 microsatellite loci and a mitochondrial DNA region (HVRI) in 12 breeding colonies in the South Shetland Islands (SSI) and the Western Antarctic Peninsula (WAP), and one previously unstudied sub-Antarctic island, 3600 km away from the WAP (Bouvetøya). High genetic diversity, evidence of female bias-dispersal and a sign of population expansion after the last glacial maximum around 10,000 mya were detected. Limited population genetic structure and lack of isolation by distance throughout the region were found, along with no differentiation between the WAP and Bouvetøya (overall microsatellite F  = 0.002, p = 0.273; mtDNA F  = - 0.004, p = 0.766), indicating long distance dispersal. Therefore, genetic assignment tests could not assign individuals to their population(s) of origin. The most differentiated location was Georges Point, one of the southernmost breeding colonies of this species in the WAP.

Conclusions: The subtle differentiation found may be explained by some combination of low natal philopatric behavior, high rates of dispersal and/or generally high mobility among colonies of chinstrap penguins compared to other Pygoscelis species.
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http://dx.doi.org/10.1186/s12862-018-1207-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6001010PMC
June 2018

Genetic structure and demographic inference of the regular sea urchin Sterechinus neumayeri (Meissner, 1900) in the Southern Ocean: The role of the last glaciation.

PLoS One 2018 6;13(6):e0197611. Epub 2018 Jun 6.

Instituto de Ecología y Biodiversidad (IEB), Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras, Ñuñoa, Santiago, Chile.

One of the most relevant characteristics of the extant Southern Ocean fauna is its resiliency to survive glacial processes of the Quaternary. These climatic events produced catastrophic habitat reductions and forced some marine benthic species to move, adapt or go extinct. The marine benthic species inhabiting the Antarctic upper continental shelf faced the Quaternary glaciations with different strategies that drastically modified population sizes and thus affected the amount and distribution of intraspecific genetic variation. Here we present new genetic information for the most conspicuous regular sea urchin of the Antarctic continental shelf, Sterechinus neumayeri. We studied the patterns of genetic diversity and structure in this broadcast-spawner across three Antarctic regions: Antarctic Peninsula, the Weddell Sea and Adélie Land in East Antarctica. Genetic analyses based on mitochondrial and nuclear markers suggested that S. neumayeri is a single genetic unit around the Antarctic continent. The species is characterized by low levels of genetic diversity and exhibits a typical star-like haplotype genealogy that supports the hypothesis of a single in situ refugium. Based on two mutation rates standardized for this genus, the Bayesian Skyline plot analyses detected a rapid demographic expansion after the Last Glacial Maximum. We propose a scenario of rapid postglacial expansion and recolonization of Antarctic shallow areas from a less ice-impacted refugium where the species survived the LGM. Considering the patterns of genetic diversity and structure recorded in the species, this refugium was probably located in East Antarctica.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0197611PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5991379PMC
December 2018

Variation in fine-scale genetic structure and local dispersal patterns between peripheral populations of a South American passerine bird.

Ecol Evol 2017 10 8;7(20):8363-8378. Epub 2017 Sep 8.

Instituto de Ecología y Biodiversidad Departamento de Ciencias Ecológicas Facultad de Ciencias Universidad de Chile Santiago Chile.

The distribution of suitable habitat influences natal and breeding dispersal at small spatial scales, resulting in strong microgeographic genetic structure. Although environmental variation can promote interpopulation differences in dispersal behavior and local spatial patterns, the effects of distinct ecological conditions on within-species variation in dispersal strategies and in fine-scale genetic structure remain poorly understood. We studied local dispersal and fine-scale genetic structure in the thorn-tailed rayadito (), a South American bird that breeds along a wide latitudinal gradient. We combine capture-mark-recapture data from eight breeding seasons and molecular genetics to compare two peripheral populations with contrasting environments in Chile: Navarino Island, a continuous and low density habitat, and Fray Jorge National Park, a fragmented, densely populated and more stressful environment. Natal dispersal showed no sex bias in Navarino but was female-biased in the more dense population in Fray Jorge. In the latter, male movements were restricted, and some birds seemed to skip breeding in their first year, suggesting habitat saturation. Breeding dispersal was limited in both populations, with males being more philopatric than females. Spatial genetic autocorrelation analyzes using 13 polymorphic microsatellite loci confirmed the observed dispersal patterns: a fine-scale genetic structure was only detectable for males in Fray Jorge for distances up to 450 m. Furthermore, two-dimensional autocorrelation analyzes and estimates of genetic relatedness indicated that related males tended to be spatially clustered in this population. Our study shows evidence for context-dependent variation in natal dispersal and corresponding local genetic structure in peripheral populations of this bird. It seems likely that the costs of dispersal are higher in the fragmented and higher density environment in Fray Jorge, particularly for males. The observed differences in microgeographic genetic structure for rayaditos might reflect the genetic consequences of population-specific responses to contrasting environmental pressures near the range limits of its distribution.
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http://dx.doi.org/10.1002/ece3.3342DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5648682PMC
October 2017

Lineage divergence, local adaptation across a biogeographic break, and artificial transport, shape the genetic structure in the ascidian Pyura chilensis.

Sci Rep 2017 03 16;7:44559. Epub 2017 Mar 16.

Departamento de Biología Marina, Facultad de Ciencias del Mar, Universidad Católica del Norte, 1781421, Coquimbo, Chile.

Marine benthic organisms inhabit a heterogeneous environment in which connectivity between populations occurs mainly through dispersive larval stages, while local selective pressures acting on early life history stages lead to non-random mortality, shaping adaptive genetic structure. In order to test the influence of local adaptation and neutral processes in a marine benthic species with low dispersal, in this study we used Genotyping by Sequencing technology to compare the neutral and putatively selected signals (neutral and outlier loci, respectively) in SNPs scattered throughout the genome in six local populations of the commercially exploited ascidian Pyura chilensis along the southeast Pacific coast (24°-42°S). This species is sessile as an adult, has a short-lived larval stage, and may also be dispersed by artificial transport as biofouling. We found that the main signal in neutral loci was a highly divergent lineage present at 39°S, and a subjacent signal that indicated a separation at 30°S (north/south), widely reported in the area. North/south separation was the main signal in outlier loci, and the linage divergence at 39°S was subjacent. We conclude that the geographic structure of the genetic diversity of outlier and neutral loci was established by different strengths of environmental, historical and anthropogenic factors.
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http://dx.doi.org/10.1038/srep44559DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5353582PMC
March 2017

Pattern of genetic differentiation of an incipient speciation process: The case of the high Andean killifish Orestias.

PLoS One 2017 28;12(2):e0170380. Epub 2017 Feb 28.

Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Ñuñoa, Santiago, Región Metropolitana, Chile.

During the Pleistocene and Holocene, the southwest Andean Altiplano (17°-22°S) was affected by repeated fluctuations in water levels, high volcanic activity and major tectonic movements. In the early Holocene the humid Tauca phase shifted to the arid conditions that have lasted until the present, producing endorheic rivers, lakes, lagoons and wetlands. The endemic fish Orestias (Cyprinodontidae) represents a good model to observe the genetic differentiation that characterizes an incipient speciation process in allopatry since the morphospecies described inhabit a restricted geographic area, with present habitat fragmentation. The genetic diversity and population structure of four endemic morphospecies of Orestias (Cyprinodontidae) found in the Lauca National Park (LNP) analyzed with mitochondrial markers (Control Region) and eight microsatellites, revealed the existence of genetic groups that matches the fragmentation of these systems. High values of genetic and phylogeographic differentiation indices were observed between Chungará Lake and Piacota lagoon. The group composed of the Lauca River, Copapujo and Chuviri wetlands sampling sites showed a clear signal of expansion, with a star-like haplotype network. Levels of genetic differentiation were lower than in Chungará and Piacota, suggesting that these localities would have differentiated after the bottlenecks linked to the collapse of Parinacota volcano. The Parinacota sample showed a population signal that differed from the other localities revealing greater genetic diversity and a disperse network, presenting haplotypes shared with other LNP localities. A mixing pattern of the different genetic groups was evident using the microsatellite markers. The chronology of the vicariance events in LNP may indicate that the partition process of the Orestias populations was gradual. Considering this, and in view of the genetic results, we may conclude that the morphospecies from LNP are populations in ongoing differentiation process.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0170380PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5330459PMC
September 2017

Biogeography in Cellana (Patellogastropoda, Nacellidae) with Special Emphasis on the Relationships of Southern Hemisphere Oceanic Island Species.

PLoS One 2017 18;12(1):e0170103. Epub 2017 Jan 18.

GAIA-Antártica, Universidad de Magallanes, Punta Arenas, Chile.

Oceanic islands lacking connections to other land are extremely isolated from sources of potential colonists and have acquired their biota mainly through dispersal from geographically distant areas. Hence, isolated island biota constitutes interesting models to infer biogeographical mechanisms of dispersal, colonization, differentiation, and speciation. Limpets of the genus Cellana (Nacellidae: Patellogastropoda) show limited dispersal capacity but are broadly distributed across the Indo-Pacific including many endemic species in isolated oceanic islands. Here, we examined main distributional patterns and geographic boundaries among Cellana lineages with special emphasis in the relationships of Southern Hemisphere oceanic islands species. Phylogenetic reconstructions based on mtDNA (COI) recognized three main clades in Cellana including taxa from different provinces of the Indo-Pacific. Clear genetic discontinuities characterize the biogeography of Cellana and several lineages are associated to particular areas of the Indo-Pacific supporting the low dispersal capacity of the genus across recognized biogeographical barriers in the region. However, evolutionary relationships within Cellana suggest that long-distance dispersal processes have been common in the history of the genus and probably associated to the origin of the species in Hawaii and Juan Fernández Archipelago. Therefore, the presence of Cellana species in geographically distant Southern Hemisphere oceanic islands, such as the Juan Fernández Archipelago, suggests that long-distance dispersal mediated by rafting may have played an important role in the biogeography of the genus.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0170103PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5242442PMC
August 2017

Marked phylogeographic structure of Gentoo penguin reveals an ongoing diversification process along the Southern Ocean.

Mol Phylogenet Evol 2017 02 8;107:486-498. Epub 2016 Dec 8.

Instituto de Ecología y Biodiversidad, Departamento de Ciencias Ecológicas, Universidad de Chile, Santiago, Chile.

Two main hypotheses have been debated about the biogeography of the Southern Ocean: (1) the Antarctic Polar Front (APF), acting as a barrier between Antarctic and sub-Antarctic provinces, and (2) the Antarctic Circumpolar Current (ACC), promoting gene flow among sub-Antarctic areas. The Gentoo penguin is distributed throughout these two provinces, separated by the APF. We analyzed mtDNA (HVR1) and 12 microsatellite loci of 264 Gentoo penguins, Pygoscelis papua, from 12 colonies spanning from the Western Antarctic Peninsula and the South Shetland Islands (WAP) to the sub-Antarctic Islands (SAI). While low genetic structure was detected among WAP colonies (mtDNA Ф=0.037-0.133; microsatellite F=0.009-0.063), high differentiation was found between all SAI and WAP populations (mtDNA Ф=0.678-0.930; microsatellite F=0.110-0.290). These results suggest that contemporary dispersal around the Southern Ocean is very limited or absent. As predicted, the APF appears to be a significant biogeographical boundary for Gentoo penguin populations; however, the ACC does not promote connectivity in this species. Our data suggest demographic expansion in the WAP during the last glacial maximum (LGM, about 20kya), but stability in SAI. Phylogenetic analyses showed a deep divergence between populations from the WAP and those from the SAI. Therefore, taxonomy should be further revised. The Crozet Islands resulted as a basal clade (3.57Mya), followed by the Kerguelen Islands (2.32Mya) as well as a more recent divergence between the Falkland/Malvinas Islands and the WAP (1.27Mya). Historical isolation, local adaptation, and past climate scenarios of those Evolutionarily Significant Units may have led to different potentials to respond to climate changes.
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http://dx.doi.org/10.1016/j.ympev.2016.12.003DOI Listing
February 2017

Genetics, Gene Flow, and Glaciation: The Case of the South American Limpet Nacella mytilina.

PLoS One 2016 6;11(9):e0161963. Epub 2016 Sep 6.

Instituto de Ecología y Biodiversidad (IEB), Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras # 3425, Ñuñoa, Santiago, Chile.

Glacial episodes of the Quaternary, and particularly the Last Glacial Maximum (LGM) drastically altered the distribution of the Southern-Hemisphere biota, principally at higher latitudes. The irregular coastline of Patagonia expanding for more than 84.000 km constitutes a remarkable area to evaluate the effect of Quaternary landscape and seascape shifts over the demography of near-shore marine benthic organisms. Few studies describing the biogeographic responses of marine species to the LGM have been conducted in Patagonia, but existing data from coastal marine species have demonstrated marked genetic signatures of post-LGM recolonization and expansion. The kelp-dweller limpet Nacella mytilina is broadly distributed along the southern tip of South America and at the Falkland/Malvinas Islands. Considering its distribution, abundance, and narrow bathymetry, N. mytilina represents an appropriate model to infer how historical and contemporary processes affected the distribution of intraspecific genetic diversity and structure along the southern tip of South America. At the same time, it will be possible to determine how life history traits and the ecology of the species are responsible for the current pattern of gene flow and connectivity across the study area. We conducted phylogeographic and demographic inference analyses in N. mytilina from 12 localities along Pacific Patagonia (PP) and one population from the Falkland/Malvinas Islands (FI). Analyses of the mitochondrial gene COI in 300 individuals of N. mytilina revealed low levels of genetic polymorphism and the absence of genetic differentiation along PP. In contrast, FI showed a strong and significant differentiation from Pacific Patagonian populations. Higher levels of genetic diversity were also recorded in the FI population, together with a more expanded genealogy supporting the hypothesis of glacial persistence of the species in these islands. Haplotype genealogy, and mismatch analyses in the FI population recognized an older and more complex demographic history than in PP. Demographic reconstructions along PP suggest a post-LGM expansion process (7.5 ka), also supported by neutrality tests, mismatch distribution and maximum parsimony haplotype genealogies. Migration rate estimations showed evidence of asymmetrical gene flow from PP to FI. The absence of genetic differentiation, the presence of a single dominant haplotype, high estimated migration rates, and marked signal of recent demographic growth, support the hypothesis of rapid post-glacial expansion in N. mytilina along PP. This expansion could have been sustained by larval and rafting-mediated dispersal of adults from northernmost populations following the Cape Horn Current System. Marked genetic differentiation between PP and FI could be explained through differences in their respective glacial histories. During the LGM, Pacific Patagonia (PP) was almost fully covered by the Patagonian Ice Sheet, while sheet coverage in the FI ice was restricted to small cirques and valleys. As previously recorded in the sister-species N. magellanica, the FI rather than represent a classical glacial refugium for N. mytilina, seems to represent a sink area and/or a secondary contact zone. Accordingly, historical and contemporary processes, contrasting glacial histories between the analyzed sectors, as well as life history traits constitute the main factors explaining the current biogeographical patterns of most shallow Patagonian marine benthic organisms.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0161963PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5012656PMC
August 2017

Filling phylogenetic gaps and the biogeographic relationships of the Octodontidae (Mammalia: Hystricognathi).

Mol Phylogenet Evol 2016 12 24;105:96-101. Epub 2016 Aug 24.

Instituto de Ecología y Biodiversidad (IEB), Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile.

Endemic to South America, octodontid rodents are remarkable by being the only mammal taxa where allotetraploidy has been documented. The taxon's extensive morpho-physiological radiation associated to niche shifts has allowed testing phylogeographic hypotheses. Using maximum likelihood and Bayesian inference analyses, applied to all nominal species of octodontids, phylogenetic reconstructions based on sequences of 12S rRNA and growth hormone receptor gene are presented. Species boundaries were determined by coalescent analyses and divergence times among taxa were estimated based on mutation rates. Two main clades associated to the Andean orogenesis were recognized. The essentially western clade comprises genera Aconaemys, Octodon, Spalacopus, and Octodontomys whereas the eastern one included genera Octomys, Pipanacoctomys, Salinoctomys, and Tympanoctomys. Genetic relationships, coalescent analyses, and genetic distance supported the specific status given to Octodon pacificus and that given to Pipanacoctomys aureus as a species of Tympanoctomys. However, these analyses failed to recognize Salinoctomys loschalchalerosorum as a valid taxon considering its position within the diversity of Tympanoctomys barrerae. Although the origin of genome duplication remains contentious, the coincidence of the basal clade split with distinctive modes of karyotypic evolution across the Andes emphasizes the role of physiographic barriers and westerlies in shaping different edaphological conditions, selective grounds, and concomitantly distinct adaptations within the octodontids.
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http://dx.doi.org/10.1016/j.ympev.2016.08.015DOI Listing
December 2016

Molecular systematics and taxonomic status of three latitudinally widespread nototheniid (Perciformes: Notothenioidei) fishes from the Southern Ocean.

Zootaxa 2016 Jan 8;4061(4):381-96. Epub 2016 Jan 8.

Instituto de Ecología y Biodiversidad, Departamento de Ciencias Ecológicas, Universidad de Chile, Las Palmeras 3425, Nuñoa, Santiago, Chile; Email: unknown.

The taxonomic status of the three nototheniids, Lepidonotothen squamifrons, L. larseni and Gobionotothen marionensis from different localities in the Southern Ocean is re-evaluated at the DNA level. DNA sequence divergences and phylogenetic relationship were estimated using a combined mitochondrial (mtDNA, ND2 and COI) dataset and data for one nuclear gene (S7 intron 1). Phylogenies of both datasets had Lepidonotothen kempi nested within L. squamifrons lineage, with low sequence divergences (0% to 0.4%) between the two nominal species suggesting that they are populations of one species. Therefore, these results do not support the previous splitting of L. squamifrons into different species. Similarly, the L. larseni specimens also represented a single genetic unit (0.3% to 0.6%) with low geographic variation between Atlantic and Indian Ocean specimens, which does not support the splitting of this species into geographically restricted species. The mtDNA phylogeny clearly separated individuals of G. acuta from Kerguelen, Heard and MacDonald Islands from G. marionensis individuals into different clades, with sequence divergence of 2.9% between these clades supporting they are different species.
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http://dx.doi.org/10.11646/zootaxa.4061.4.4DOI Listing
January 2016
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