Publications by authors named "Chifundera Kusamba"

21 Publications

  • Page 1 of 1

Giant Tree Frog diversification in West and Central Africa: Isolation by physical barriers, climate, and reproductive traits.

Mol Ecol 2022 Aug 28;31(15):3979-3998. Epub 2021 Sep 28.

Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.

Secondary sympatry amongst sister lineages is strongly associated with genetic and ecological divergence. This pattern suggests that for closely related species to coexist in secondary sympatry, they must accumulate differences in traits that mediate ecological and/or reproductive isolation. Here, we characterized inter- and intraspecific divergence in three giant tree frog species whose distributions stretch across West and Central Africa. Using genome-wide single-nucleotide polymorphism data, we demonstrated that species-level divergence coincides temporally and geographically with a period of large-scale forest fragmentation during the late Pliocene. Our environmental niche models further supported a dynamic history of climatic suitability and stability, and indicated that all three species occupy distinct environmental niches. We found modest morphological differentiation amongst the species with significant divergence in tympanum diameter and male advertisement call. In addition, we confirmed that two species occur in secondary sympatry in Central Africa but found no evidence of hybridization. These patterns support the hypothesis that cycles of genetic exchange and isolation across West and Central Africa have contributed to globally significant biodiversity. Furthermore, divergence in both ecology and reproductive traits appear to have played important roles in maintaining distinct lineages. At the intraspecific level, we found that climatic refugia, precipitation gradients, marine incursions, and potentially riverine barriers generated phylogeographic structure throughout the Pleistocene and into the Holocene. Further studies examining phenotypic divergence and secondary contact amongst these geographically structured populations may demonstrate how smaller scale and more recent biogeographic barriers contribute to regional diversification.
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http://dx.doi.org/10.1111/mec.16169DOI Listing
August 2022

Rivers, not refugia, drove diversification in arboreal, sub-Saharan African snakes.

Ecol Evol 2021 Jun 1;11(11):6133-6152. Epub 2021 May 1.

Department of Ecology and Evolutionary Biology University of Kansas Lawrence KS USA.

The relative roles of rivers versus refugia in shaping the high levels of species diversity in tropical rainforests have been widely debated for decades. Only recently has it become possible to take an integrative approach to test predictions derived from these hypotheses using genomic sequencing and paleo-species distribution modeling. Herein, we tested the predictions of the classic river, refuge, and river-refuge hypotheses on diversification in the arboreal sub-Saharan African snake genus . We used dated phylogeographic inferences, population clustering analyses, demographic model selection, and paleo-distribution modeling to conduct a phylogenomic and historical demographic analysis of this genus. Our results revealed significant population genetic structure within both species, corresponding geographically to river barriers and divergence times from the mid-Miocene to Pliocene. Our demographic analyses supported the interpretation that rivers are indications of strong barriers to gene flow among populations since their divergence. Additionally, we found no support for a major contraction of suitable habitat during the last glacial maximum, allowing us to reject both the refuge and river-refuge hypotheses in favor of the river-barrier hypothesis. Based on conservative interpretations of our species delimitation analyses with the Sanger and ddRAD data sets, two new cryptic species are identified from east-central Africa. This study highlights the complexity of diversification dynamics in the African tropics and the advantages of integrative approaches to studying speciation in tropical regions.
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http://dx.doi.org/10.1002/ece3.7429DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8207163PMC
June 2021

Night stalkers from above: A monograph of Toxicodryas/ tree snakes (Squamata: Colubridae) with descriptions of two new cryptic species from Central Africa.

Zootaxa 2021 Apr 27;4965(1):zootaxa.4965.1.1. Epub 2021 Apr 27.

University of Texas at El Paso, Department of Biological Sciences, 500 W. University Avenue, El Paso, Texas 79912, USA.

The genus Toxicodryas, historically included with the renowned Australasian cat-eyed snakes of the colubrid genus Boiga, currently includes two widespread species (T. blandingii and T. pulverulenta) in western, central, and eastern Africa. We leverage findings from a recent phylogenomic and historical demographic analysis of this genus (based on 2848-4471 Rad-seq loci from across the genome), with robust sampling from throughout the ranges of both species, to define two additional taxonomic units, with species boundaries corresponding to river barriers. Additional morphometric data from scores of examined museum specimens and literature records bolster the recognition of these two new cryptic species. We hypothesize that T. blandingii occurs west of the confluence of the Congo and Ubangi rivers, whereas a cryptic new species that is found east of this biogeographic barrier has significantly higher numbers of ventral scale counts in both sexes, additional significant differences in several scale counts, and lower venom toxicity. Toxicodryas pulverulenta occurs west of the Niger Delta in West Africa, whereas a cryptic new species that is found east of this biogeographic barrier has significantly higher numbers of subcaudal scale counts in both sexes. A review of published information regarding morphological variation, ecology, natural history, habitat, and venom is summarized for these four Toxicodryas species.
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http://dx.doi.org/10.11646/zootaxa.4965.1.1DOI Listing
April 2021

Evolutionary history of burrowing asps (Lamprophiidae: Atractaspidinae) with emphasis on fang evolution and prey selection.

PLoS One 2019 17;14(4):e0214889. Epub 2019 Apr 17.

Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas, United States of America.

Atractaspidines are poorly studied, fossorial snakes that are found throughout Africa and western Asia, including the Middle East. We employed concatenated gene-tree analyses and divergence dating approaches to investigate evolutionary relationships and biogeographic patterns of atractaspidines with a multi-locus data set consisting of three mitochondrial (16S, cyt b, and ND4) and two nuclear genes (c-mos and RAG1). We sampled 91 individuals from both atractaspidine genera (Atractaspis and Homoroselaps). Additionally, we used ancestral-state reconstructions to investigate fang and diet evolution within Atractaspidinae and its sister lineage (Aparallactinae). Our results indicated that current classification of atractaspidines underestimates diversity within the group. Diversification occurred predominantly between the Miocene and Pliocene. Ancestral-state reconstructions suggest that snake dentition in these taxa might be highly plastic within relatively short periods of time to facilitate adaptations to dynamic foraging and life-history strategies.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0214889PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6469773PMC
January 2020

Diversifying into the branches: Species boundaries in African green and bush snakes, Philothamnus (Serpentes: Colubridae).

Mol Phylogenet Evol 2019 01 23;130:357-365. Epub 2018 Oct 23.

South African National Biodiversity Institute, Kirstenbosch Research Centre, Private Bag X7, Claremont 7735, South Africa; Centre for Ecological Genomics and Wildlife Conservation, University of Johannesburg, Auckland Park 2000, South Africa.

The African green and bush snakes of the genus Philothamnus currently comprises 21 species and three subspecies and occurs throughout sub-Saharan Africa. The genus has been the subject of previous taxonomic revisions based on traditional morphological characters and limited genetic assessment, and may not reflect their evolutionary history. Indeed, previous findings based on phylogenetics show discordant results of interspecific relationships and question the monophyly of the genus, although taxon sampling has been limited to date. We investigated phylogenetic affinities within Philothamnus with more inclusive genetic and geographical sampling, with the aim of better understanding their evolutionary history, so that future taxonomic revision of Philothamnus can be better informed. Species relationships were examined within a phylogenetic context and sampling included 133 ingroup samples from 16 taxa. Phylogenies were constructed in Bayesian and likelihood frameworks using three mitochondrial (16S, cyt b and ND4) and two nuclear (c-mos and RAG1) markers. Competing hypotheses relating to the monophyly of the genus were tested with a Shimodaira-Hasegawa test. To examine species boundaries, Bayesian General Mixed Yule-Coalescent Model and multi-rate Poisson Tree Processes analyses were conducted. In addition, a barcoding approach was used to further clarify species-level relationships by comparing frequency distributions between intra- and interspecific sequence divergence. The genus was recovered as monophyletic; however, species-delimitation results suggest that the current taxonomy does not reflect the evolutionary history of this group. For example, Philothamnus s. semivariegatus is paraphyletic, with at least four distinct clades. Philothamnus carinatus consists of two cryptic (sister) lineages from Central and West Africa that are deeply divergent, suggesting a long history of isolation between those regions. Furthermore, the subspecies P. n. natalensis and P. n. occidentalis show strong support for species-level divergence, which reflects their morphological and ecological differences. Accordingly, we elevate P. occidentalisnov. comb. to a full species. A fully informed taxonomic revision of these taxa will require additional morphological and ecological data for corroboration, but it seems that the morphological characters (e.g. scalation, dentition) used to describe these species to date are labile within and between species. This most likely has clouded our understanding of the species boundaries within the genus. Our phylogeny and species-delimitation analyses should provide a sounder framework for taxonomy, but may also prove useful toward understanding the morphological adaptations of these species to their respective habitats.
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http://dx.doi.org/10.1016/j.ympev.2018.10.023DOI Listing
January 2019

Integration of nuclear and mitochondrial gene sequences and morphology reveals unexpected diversity in the forest cobra (Naja melanoleuca) species complex in Central and West Africa (Serpentes: Elapidae).

Zootaxa 2018 Aug 1;4455(1):68-98. Epub 2018 Aug 1.

Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Bangor LL57 2UW, United Kingdom..

Cobras are among the most widely known venomous snakes, and yet their taxonomy remains incompletely understood, particularly in Africa. Here, we use a combination of mitochondrial and nuclear gene sequences and morphological data to diagnose species limits within the African forest cobra, Naja (Boulengerina) melanoleuca. Mitochondrial DNA sequences reveal deep divergences within this taxon. Congruent patterns of variation in mtDNA, nuclear genes and morphology support the recognition of five separate species, confirming the species status of N. subfulva and N. peroescobari, and revealing two previously unnamed West African species, which are described as new: Naja (Boulengerina) guineensis sp. nov. Broadley, Trape, Chirio, Ineich Wüster, from the Upper Guinea forest of West Africa, and Naja (Boulengerina) savannula sp. nov. Broadley, Trape, Chirio Wüster, a banded form from the savanna-forest mosaic of the Guinea and Sudanian savannas of West Africa. The discovery of cryptic diversity in this iconic group highlights our limited understanding of tropical African biodiversity, hindering our ability to conserve it effectively.
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http://dx.doi.org/10.11646/zootaxa.4455.1.3DOI Listing
August 2018

Phylogeny and biogeography of the African burrowing snake subfamily Aparallactinae (Squamata: Lamprophiidae).

Mol Phylogenet Evol 2018 10 15;127:288-303. Epub 2018 Mar 15.

Department of Biological Sciences, University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, USA.

Members of the snake subfamily Aparallactinae occur in various habitats throughout sub-Saharan Africa. The monophyly of aparallactine snakes is well established, but relationships within the subfamily are poorly known. We sampled 158 individuals from six of eight aparallactine genera in sub-Saharan Africa. We employed concatenated gene-tree analyses, divergence dating approaches, and ancestral-area reconstructions to infer phylogenies and biogeographic patterns with a multi-locus data set consisting of three mitochondrial (16S, cyt b, and ND4) and two nuclear genes (c-mos and RAG1). As a result, we uncover several cryptic lineages and elevate a lineage of Polemon to full species status. Diversification occurred predominantly during the Miocene, with a few speciation events occurring subsequently in the Pliocene and Pleistocene. Biogeographic analyses suggested that the Zambezian biogeographic region, comprising grasslands and woodlands, facilitated radiations, vicariance, and dispersal for many aparallactines. Moreover, the geographic distributions of many forest species were fragmented during xeric and cooler conditions, which likely led to diversification events. Biogeographic patterns of aparallactine snakes are consistent with previous studies of other sub-Saharan herpetofauna.
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http://dx.doi.org/10.1016/j.ympev.2018.03.019DOI Listing
October 2018

Cryptic diversity in Rhampholeon boulengeri (Sauria: Chamaeleonidae), a pygmy chameleon from the Albertine Rift biodiversity hotspot.

Mol Phylogenet Evol 2018 05 2;122:125-141. Epub 2017 Dec 2.

Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA.

Several biogeographic barriers in the Central African highlands have reduced gene flow among populations of many terrestrial species in predictable ways. Yet, a comprehensive understanding of mechanisms underlying species divergence in the Afrotropics can be obscured by unrecognized levels of cryptic diversity, particularly in widespread species. We implemented a multilocus phylogeographic approach to examine diversity within the widely distributed Central African pygmy chameleon, Rhampholeon boulengeri. Gene-tree analyses coupled with a comparative coalescent-based species delimitation framework revealed R. boulengeri as a complex of at least six genetically distinct species. The spatiotemporal speciation patterns for these cryptic species conform to general biogeographic hypotheses supporting vicariance as the main factor behind patterns of divergence in the Albertine Rift, a biodiversity hotspot in Central Africa. However, we found that parapatric species and sister species inhabited adjacent habitats, but were found in largely non-overlapping elevational ranges in the Albertine Rift, suggesting that differentiation in elevation was also an important mode of divergence. The phylogeographic patterns recovered for the genus-level phylogeny provide additional evidence for speciation by isolation in forest refugia, and dating estimates indicated that the Miocene was a significant period for this diversification. Our results highlight the importance of investigating cryptic diversity in widespread species to improve understanding of diversification patterns in environmentally diverse regions such as the montane Afrotropics.
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http://dx.doi.org/10.1016/j.ympev.2017.11.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6010225PMC
May 2018

Idiosyncratic responses to climate-driven forest fragmentation and marine incursions in reed frogs from Central Africa and the Gulf of Guinea Islands.

Mol Ecol 2017 Oct 24;26(19):5223-5244. Epub 2017 Aug 24.

Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA.

Organismal traits interact with environmental variation to mediate how species respond to shared landscapes. Thus, differences in traits related to dispersal ability or physiological tolerance may result in phylogeographic discordance among co-distributed taxa, even when they are responding to common barriers. We quantified climatic suitability and stability, and phylogeographic divergence within three reed frog species complexes across the Guineo-Congolian forests and Gulf of Guinea archipelago of Central Africa to investigate how they responded to a shared climatic and geological history. Our species-specific estimates of climatic suitability through time are consistent with temporal and spatial heterogeneity in diversification among the species complexes, indicating that differences in ecological breadth may partly explain these idiosyncratic patterns. Likewise, we demonstrated that fluctuating sea levels periodically exposed a land bridge connecting Bioko Island with the mainland Guineo-Congolian forest and that habitats across the exposed land bridge likely enabled dispersal in some species, but not in others. We did not find evidence that rivers are biogeographic barriers across any of the species complexes. Despite marked differences in the geographic extent of stable climates and temporal estimates of divergence among the species complexes, we recovered a shared pattern of intermittent climatic suitability with recent population connectivity and demographic expansion across the Congo Basin. This pattern supports the hypothesis that genetic exchange across the Congo Basin during humid periods, followed by vicariance during arid periods, has shaped regional diversity. Finally, we identified many distinct lineages among our focal taxa, some of which may reflect incipient or unrecognized species.
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http://dx.doi.org/10.1111/mec.14260DOI Listing
October 2017

Leapfrogging into new territory: How Mascarene ridged frogs diversified across Africa and Madagascar to maintain their ecological niche.

Mol Phylogenet Evol 2017 01 21;106:254-269. Epub 2016 Sep 21.

Trier University, Department of Biogeography, 54286 Trier, Germany. Electronic address:

The Mascarene ridged frog, Ptychadena mascareniensis, is a species complex that includes numerous lineages occurring mostly in humid savannas and open forests of mainland Africa, Madagascar, the Seychelles, and the Mascarene Islands. Sampling across this broad distribution presents an opportunity to examine the genetic differentiation within this complex and to investigate how the evolution of bioclimatic niches may have shaped current biogeographic patterns. Using model-based phylogenetic methods and molecular-clock dating, we constructed a time-calibrated molecular phylogenetic hypothesis for the group based on mitochondrial 16S rRNA and cytochrome b (cytb) genes and the nuclear RAG1 gene from 173 individuals. Haplotype networks were reconstructed and species boundaries were investigated using three species-delimitation approaches: Bayesian generalized mixed Yule-coalescent model (bGMYC), the Poisson Tree Process model (PTP) and a cluster algorithm (SpeciesIdentifier). Estimates of similarity in bioclimatic niche were calculated from species-distribution models (maxent) and multivariate statistics (Principal Component Analysis, Discriminant Function Analysis). Ancestral-area reconstructions were performed on the phylogeny using probabilistic approaches implemented in BioGeoBEARS. We detected high levels of genetic differentiation yielding ten distinct lineages or operational taxonomic units, and Central Africa was found to be a diversity hotspot for these frogs. Most speciation events took place throughout the Miocene, including "out-of-Africa" overseas dispersal events to Madagascar in the East and to São Tomé in the West. Bioclimatic niche was remarkably well conserved, with most species tolerating similar temperature and rainfall conditions common to the Central African region. The P. mascareniensis complex provides insights into how bioclimatic niche shaped the current biogeographic patterns with niche conservatism being exhibited by the Central African radiation and niche divergence shaping populations in West Africa and Madagascar. Central Africa, including the Albertine Rift region, has been an important center of diversification for this species complex.
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http://dx.doi.org/10.1016/j.ympev.2016.09.018DOI Listing
January 2017

Molecular phylogeny of Panaspis and Afroablepharus skinks (Squamata: Scincidae) in the savannas of sub-Saharan Africa.

Mol Phylogenet Evol 2016 07 23;100:409-423. Epub 2016 Apr 23.

Department of Biological Sciences, University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, USA. Electronic address:

African snake-eyed skinks are relatively small lizards of the genera Panaspis and Afroablepharus. Species allocation of these genera frequently changed during the 20th century based on morphology, ecology, and biogeography. Members of these genera occur primarily in savanna habitats throughout sub-Saharan Africa and include species whose highly conserved morphology poses challenges for taxonomic studies. We sequenced two mitochondrial (16S and cyt b) and two nuclear genes (PDC and RAG1) from 76 Panaspis and Afroablepharus samples from across eastern, central, and southern Africa. Concatenated gene-tree and divergence-dating analyses were conducted to infer phylogenies and biogeographic patterns. Molecular data sets revealed several cryptic lineages, with most radiations occurring during the mid-Miocene to Pliocene. We infer that rifting processes (including the formation of the East African Rift System) and climatic oscillations contributed to the expansion and contraction of savannas, and caused cladogenesis in snake-eyed skinks. Species in Panaspis and Afroablepharus used in this study, including type species for both genera, formed a monophyletic group. As a result, the latter genus should be synonymized with the former, which has priority. Conservatively, we continue to include the West African species P. breviceps and P. togoensis within an expanded Panaspis, but note that they occur in relatively divergent clades, and their taxonomic status may change with improved taxon sampling. Divergence estimates and cryptic speciation patterns of snake-eyed skinks were consistent with previous studies of other savanna vertebrate lineages from the same areas examined in this study.
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http://dx.doi.org/10.1016/j.ympev.2016.04.026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4898058PMC
July 2016

Pan-African phylogeography of a model organism, the African clawed frog 'Xenopus laevis'.

Mol Ecol 2015 Feb 3;24(4):909-25. Epub 2015 Feb 3.

Biology Department, McMaster University, Life Sciences Building, 1280 Main Street West, Hamilton, Ontario, Canada, L8S 4K1.

The African clawed frog Xenopus laevis has a large native distribution over much of sub-Saharan Africa and is a model organism for research, a proposed disease vector, and an invasive species. Despite its prominent role in research and abundance in nature, surprisingly little is known about the phylogeography and evolutionary history of this group. Here, we report an analysis of molecular variation of this clade based on 17 loci (one mitochondrial, 16 nuclear) in up to 159 individuals sampled throughout its native distribution. Phylogenetic relationships among mitochondrial DNA haplotypes were incongruent with those among alleles of the putatively female-specific sex-determining gene DM-W, in contrast to the expectation of strict matrilineal inheritance of both loci. Population structure and evolutionarily diverged lineages were evidenced by analyses of molecular variation in these data. These results further contextualize the chronology, and evolutionary relationships within this group, support the recognition of X. laevis sensu stricto, X. petersii, X. victorianus and herein revalidated X. poweri as separate species. We also propose that portions of the currently recognized distributions of X. laevis (north of the Congo Basin) and X. petersii (south of the Congo Basin) be reassigned to X. poweri.
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http://dx.doi.org/10.1111/mec.13076DOI Listing
February 2015

Recent divergences and size decreases of eastern gorilla populations.

Biol Lett 2014 Nov;10(11):20140811

Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig 04103, Germany

Compared with other African apes, eastern gorillas (Gorilla beringei) have been little studied genetically. We used analysis of autosomal DNA genotypes obtained from non-invasively collected faecal samples to estimate the evolutionary histories of the two extant mountain gorilla populations and the closely related eastern lowland gorillas. Our results suggest that eastern lowland gorillas and mountain gorillas split beginning some 10 000 years ago, followed 5000 years ago by the split of the two mountain gorilla populations of Bwindi Impenetrable National Park and the Virungas Massif. All three populations have decreased in effective population size, with particularly substantial 10-fold decreases for the mountain gorillas. These dynamics probably reflect responses to habitat changes resulting from climate fluctuations over the past 20 000 years as well as increasing human influence in this densely populated region in the last several thousand years.
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http://dx.doi.org/10.1098/rsbl.2014.0811DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4261871PMC
November 2014

Phylogeography and species boundaries of Leptopelis (Anura: Arthroleptidae) from the Albertine Rift.

Mol Phylogenet Evol 2015 Jan 5;82 Pt A:75-86. Epub 2014 Oct 5.

Institut für Integrierte Naturwissenschaften, Abteilung Biologie, AG Zoologie, Universität Koblenz-Landau, Universitätsstraße 1, 56070 Koblenz, Germany.

The genus Leptopelis occurs in multiple habitats throughout sub-Saharan Africa, and it includes several species that have highly variable color patterns, which makes taxonomic studies challenging. In this study, we examined multiple populations of Leptopelis from the Albertine Rift (AR), a region known for its high levels of endemism and biodiversity. Currently, five species are recognized from the AR: L. anebos, L. fiziensis, L. karissimbensis, L. kivuensis, and L. mtoewaate, most of which are found in and around the Itombwe Plateau in Democratic Republic of the Congo (DRC). We sampled 90 individuals of Leptopelis from multiple localities in DRC, Uganda, Rwanda and Burundi. We employed concatenated gene-tree analyses, coalescent species-tree analyses, and divergence dating approaches to infer phylogenies and biogeographic patterns with a multi-locus data set consisting of two mitochondrial (16S and cyt b) and one nuclear gene (RAG1). All analyses revealed several cryptic lineages within the genus, suggesting that a revision of AR Leptopelis taxonomy is needed.
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http://dx.doi.org/10.1016/j.ympev.2014.09.024DOI Listing
January 2015

Hyaluronidase, phospholipase A2 and protease inhibitory activity of plants used in traditional treatment of snakebite-induced tissue necrosis in Mali, DR Congo and South Africa.

J Ethnopharmacol 2014 Nov 23;157:171-80. Epub 2014 Sep 23.

Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark. Electronic address:

Ethnopharmacological Relevance: Snakebite envenomation, every year, causes estimated 5-10,000 mortalities and results in more than 5-15,000 amputations in sub-Saharan Africa alone. Antiserum is not easily accessible in these regions or doctors are simply not available, thus more than 80% of all patients seek traditional practitioners as first-choice. Therefore it is important to investigate whether the plants used in traditional medicine systems contain compounds against the necrosis-inducing enzymes of snake venom.

Materials And Methods: Extracts from traditionally used plants from DR Congo, Mali and South Africa were tested in hyaluronidase, phospholipase A2 and protease enzyme bioassays using Bitis arietans and Naja nigricollis as enzyme source.

Results: A total of 226 extracts from 94 different plant species from the three countries, Mali, Democratic Republic of Congo and South Africa were tested in phospholipase A2, proteases and hyaluronidase enzyme assays. Forty plant species showed more than 90% inhibition in one or more assay. Fabaceae, Anacardiaceae and Malvaceae were the families with the highest number of active species, and the active compounds were distributed in different plant parts depending on plant species. Polyphenols were removed in the search for specific enzyme inhibitors against hyaluronidase, phospholipase A2 or proteases from extracts with IC50 values below 100µg/ml. Water extracts of Pupalia lappacea, Combretum molle, Strychnos innocua and Grewia mollis and ethanol extract of Lannea acida and Bauhinia thonningii still showed IC50 values below 100µg/ml in either the hyaluronidase or protease bioassay after removal of polyphenols.

Conclusion: As four of the active plants are widely distributed in the areas where the snake species Bitis arietans and Naja nigricollis occur a potential inhibitor of the necrotic enzymes is accessible for many people in sub-Saharan Africa.
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http://dx.doi.org/10.1016/j.jep.2014.09.027DOI Listing
November 2014

Phylogeography of the reed frog Hyperolius castaneus (Anura: Hyperoliidae) from the Albertine Rift of Central Africa: implications for taxonomy, biogeography and conservation.

Zootaxa 2013 Nov 1;3731:473-94. Epub 2013 Nov 1.

Affiliation: unknown; Email: unknown.

We examine the systematics of multiple populations of the Albertine Rift endemic amphibian Hyperolius castaneus, which currently incorporates four subspecies. Standard morphometric data were analyzed with principal components analyses and analyses of covariance. Phylogenetic analyses of two mitochondrial (16S, cyt b) and one nuclear (RAG1) genes were analyzed from 41 samples representing three subspecies. Results indicated some significant morphometric differences between the nominate subspecies H. c. castaneus and the Itombwe Plateau subspecies H. c. constellatus, and phylogenetic analyses of molecular data recovered these taxa as reciprocally monophyletic groups. We recognize these two allopatric populations as recently diverged, but distinct species, H. castaneus and H. constellatus. The subspecies H. c. submarginatus from the Kabobo Plateau is transferred to the synonymy of H. constellatus, but the status of the unsampled subspecies H. c. rhodogaster, described from mid-elevations of the western Itombwe Plateau, remains problematic. The phylogeographic pattern of our study resembles some, but not all, Albertine Rift vertebrates that have been examined with molecular data. Hyperolius constellatus is restricted to the Itombwe and Kabobo plateaus, which are of special conservation concern because of high levels of amphibian diversity and endemism, and multiple threats from deforestation, mining activities and road construction.
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http://dx.doi.org/10.11646/zootaxa.3731.4.3DOI Listing
November 2013

Systematics of the poorly known treefrog (Anura: Arthroleptidae), with a description of its call.

Afr J Herpetol 2012 18;61(2):113-127. Epub 2012 Sep 18.

Department of Biological Sciences, University of Texas at El Paso, 500 W. University Avenue, El Paso, TX 79968, USA.

was described as a subspecies of from specimens that were collected in 1956 in the region in and around Fizi, in present-day Democratic Republic of the Congo. We recently discovered in transitional and montane forest near the type locality and the southeastern Itombwe Plateau, respectively. A phylogenetic analysis (16S mitochondrial sequence data) of these samples and other species recovered as sister to with strong support, and rejected a close relationship between and both topotypic from Cameroon and from Kenya. Herein, we provide a detailed description of the morphometrics, colour pattern, male advertisement call and natural history of this poorly known species. At least one literature record of from Tanzania has notable differences from our data, and requires further study to ascertain its taxonomic status.
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http://dx.doi.org/10.1080/21564574.2012.716083DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3583300PMC
September 2012

A molecular phylogeny of Equatorial African Lacertidae, with the description of a new genus and species from eastern Democratic Republic of the Congo.

Zool J Linn Soc 2011 Nov;163(3):913-942

Department of Biological Sciences, University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968, USA.

Currently, four species of the lacertid lizard genus Adolfus are known from Central and East Africa. We sequenced up to 2,825 bp of two mitochondrial (16S and cyt b) and two nuclear (c-mos and RAG1) genes from 41 samples of Adolfus (representing every species), two species each of Gastropholis and Holaspis, and in separate analyses combined this data with GenBank sequences of all other Eremiadini genera and four Lacertini outgroups. Data from DNA sequences were analyzed with maximum parsimony (PAUP), maximum-likelihood (RAxML) and Bayesian inference (MrBayes) criteria. Results demonstrated that Adolfus is not monophyletic: A. africanus (type species), A. alleni and A. jacksoni are sister taxa, whereas A. vauereselli and a new species from the Itombwe Plateau of Democratic Republic of the Congo are in a separate lineage. Holaspis and Gastropholis were recovered in separate clades. Based on this molecular data, relatively substantial sequence divergence and multiple morphological differences, we describe a new genus of lacertid for the lineage including A. vauereselli and the new Itombwe species. The recognition of this new, endemic genus underscores the conservation importance of the Albertine Rift, especially the Itombwe Plateau, a unique region that is severely threatened by unchecked deforestation, mining and poaching.
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http://dx.doi.org/10.1111/j.1096-3642.2011.00732.xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3222588PMC
November 2011

Polyketides from Eleutherine bulbosa.

Nat Prod Res 2010 Oct;24(16):1578-86

Dipartimento del Farmaco, Istituto Superiore di Sanita, I-00161 Rome, Italy.

Four new polyketides, (R)-4-hydroxyeleutherin, eleuthone, eleutherinol-8-O-β-D-glucoside and isoeleuthoside C (dihydroisoeleutherin-5-O-β-D-gentiobioside) were isolated from the bulbs of Eleutherine bulbosa, to join eleutherin, isoeleutherin, eleutherinol, eleutherol, eleuthoside B (eleutherol-4-O-β-D-gentiobioside), eleuthoside C (dihydroeleutherin-5-O-β-D-gentiobioside), hongconin (4-oxodihydroisoeleutherin) and elecanacin, which have already been isolated from the same plant. The structures of the new polyketides, based on oxydated cyclic systems, have been elucidated by chemical and spectroscopic methods.
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http://dx.doi.org/10.1080/14786419.2010.500007DOI Listing
October 2010

Oligomeric secoiridoid glucosides from Jasminum abyssinicum.

Phytochemistry 2006 Mar 27;67(5):504-10. Epub 2005 Dec 27.

Dipartimento del Farmaco, Istituto Superiore di Sanità, V. le Regina Elena 299, 00161 Rome, Italy.

From the root bark of Jasminum abyssinicum (Oleaceae) collected in Congo was isolated tree oligomeric secoiridoid glucosides named craigosides A-C. The three compounds are esters of a cyclopentanoid monoterpene with an iridane skeleton, esterified with three, two and two, respectively, units of oleoside 11-methyl ester. The structures were elucidated by spectroscopic methods and chemical correlations.
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http://dx.doi.org/10.1016/j.phytochem.2005.11.007DOI Listing
March 2006

Screening of African medicinal plants for antimicrobial and enzyme inhibitory activity.

J Ethnopharmacol 2002 Apr;80(1):25-35

Institute for Pharmaceutical Biology, Nussallee 6, D-53115, Bonn, Germany.

Seven plant species, belonging to different families, were collected in the eastern part of the Republic of Congo (Kivu) based on ethnopharmacological information. Their dichloromethane and methanolic extracts were tested for biological activity. Five of the seven collected plants exhibited antiplasmodial activity with IC(50) values ranging from 1.1 to 9.8 microg/ml. The methanolic extract of Cissampelos mucronata was the most active one showing activity against chloroquine sensitive (D6) and chloroquine resistant (W2) Plasmodium falciparum strains with IC(50) values of 1.5 and 1.1 microg/ml, respectively. Additionally, this extract significantly inhibited the enzyme tyrosine kinase p56(lck) (TK). The dichloromethane extract of Amorphophallus bequaertii inhibited the growth of Mycobacterium tuberculosis with a MIC of 100 microg/ml and the methanolic extract of Rubus rigidus inhibited the activity of both enzymes HIV1-reverse transcriptase (HIV1-RT) and TK p56(lck).
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http://dx.doi.org/10.1016/s0378-8741(01)00409-3DOI Listing
April 2002
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