Publications by authors named "Maya Lalzar"

14 Publications

  • Page 1 of 1

Particle-associated and free-living bacterial communities in an oligotrophic sea are affected by different environmental factors.

Environ Microbiol 2021 May 25. Epub 2021 May 25.

Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel.

In the oceans and seas, environmental conditions change over multiple temporal and spatial scales. Here, we ask what factors affect the bacterial community structure across time, depth and size fraction during six seasonal cruises (2 years) in the ultra-oligotrophic Eastern Mediterranean Sea. The bacterial community varied most between size fractions (free-living (FL) vs. particle-associated), followed by depth and finally season. The FL community was taxonomically richer and more stable than the particle-associated (PA) one, which was characterized by recurrent 'blooms' of heterotrophic bacteria such as Alteromonas and Ralstonia. The heterotrophic FL and PA communities were also correlated with different environmental parameters: the FL population correlated with depth and phytoplankton, whereas PA bacteria were correlated primarily with the time of sampling. A significant part of the variability in community structure could, however, not be explained by the measured parameters. The metabolic potential of the PA community, predicted from 16S rRNA amplicon data using PICRUSt, was enriched in pathways associated with the degradation and utilization of biological macromolecules, as well as plastics, other petroleum products and herbicides. The FL community was enriched in predicted pathways for the metabolism of inositol phosphate, a potential phosphorus source, and of polycyclic aromatic hydrocarbons.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/1462-2920.15611DOI Listing
May 2021

Geographic partitioning or environmental selection: What governs the global distribution of bacterial communities inhabiting floral nectar?

Sci Total Environ 2020 Dec 12;749:142305. Epub 2020 Sep 12.

Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel.

Floral nectar harbors microbial communities which have significant impacts on its chemistry, volatiles, nutritional contents, and attractiveness for pollinators. Yet, fundamental knowledge regarding the structure and composition of nectar-associated microbiomes remains largely unknown. Especially elusive are the environmental factors and spatial effects that shape nectar-inhabiting microbial communities. The aim of this study was to explore and analyze the role of geographical and environmental factors affecting the composition and global distribution of floral nectar microbiota. We explored and compared the structure of bacterial communities inhabiting the floral nectar of the widely spread and invasive tobacco tree (Nicotiana glauca) in six continents: South and North America, Australia, Europe, Africa, and Asia, using 16S rRNA gene sequencing. Environmental abiotic data for each sampled plant was obtained from the Worldclim database and applied for inferring the effects of environmental conditions on bacterial community structure and diversity. Most abundant in the nectar were the Proteobacteria, Firmicutes, and Actinobacteria phyla, with Acinetobacter and Rosenbergiella (Proteobacteria) being the dominant bacterial genera that contributed most to the dissimilarities between sites. Acinetobacter and Rosenbergiella abundances were negatively correlated and significantly higher in the Mediterranean regions (Greece, Israel, and the Canary Islands) compared to Argentina and Australia. Temperature, site-elevation, rainfall, and density of vegetation were found to have significant effects on the structure and diversity of these bacterial communities in the nectar. Vegetation density was positively correlated with microbial diversity, while increased temperatures and elevation reduced the diversity and evenness of bacterial communities. Mantel's test showed that the similarity between the bacterial communities' composition significantly decreased as distances between them increased. We conclude that both geographical distance and local environmental abiotic conditions affect and shape the composition and diversity of nectar inhabiting bacterial communities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.scitotenv.2020.142305DOI Listing
December 2020

The effect of toxic pyridine-alkaloid secondary metabolites on the sunbird gut microbiome.

NPJ Biofilms Microbiomes 2020 11 13;6(1):53. Epub 2020 Nov 13.

Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa, Israel.

Sunbirds feed on tobacco tree nectar which contains toxic nicotine and anabasine secondary metabolites. Our aim was to understand the effect of nicotine and anabasine on the gut microbiota composition of sunbirds. Sixteen captive sunbirds were randomly assigned to two diets: artificial nectar either with (treatment) or without (control) added nicotine and anabasine. Excreta were collected at 0, 2, 4 and 7 weeks of treatment and samples were processed for bacterial culture and high-throughput amplicon sequencing of the 16S rRNA gene. The gut microbiome diversity of the treated and control birds changed differently along the seven-week experiment. While the diversity decreased in the control group along the first three samplings (0, 2 and 4 weeks), it increased in the treatment group. The microbiota composition analyses demonstrated that a diet with nicotine and anabasine, significantly changed the birds' gut microbiota composition compared to the control birds. The abundance of nicotine- and anabasine- degrading bacteria in the excreta of the treated birds, was significantly higher after four and seven weeks compared to the control group. Furthermore, analysis of culturable isolates, including Lactococcus, showed that sunbirds' gut-associated bacteria were capable of degrading nicotine and anabasine, consistent with their hypothesised role as detoxifying and nutritional symbionts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41522-020-00161-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7666580PMC
November 2020

eIF2α controls memory consolidation via excitatory and somatostatin neurons.

Nature 2020 10 7;586(7829):412-416. Epub 2020 Oct 7.

Department of Biochemistry, McGill University, Montréal, Québec, Canada.

An important tenet of learning and memory is the notion of a molecular switch that promotes the formation of long-term memory. The regulation of proteostasis is a critical and rate-limiting step in the consolidation of new memories. One of the most effective and prevalent ways to enhance memory is by regulating the synthesis of proteins controlled by the translation initiation factor eIF2. Phosphorylation of the α-subunit of eIF2 (p-eIF2α), the central component of the integrated stress response (ISR), impairs long-term memory formation in rodents and birds. By contrast, inhibiting the ISR by mutating the eIF2α phosphorylation site, genetically and pharmacologically inhibiting the ISR kinases, or mimicking reduced p-eIF2α with the ISR inhibitor ISRIB, enhances long-term memory in health and disease. Here we used molecular genetics to dissect the neuronal circuits by which the ISR gates cognitive processing. We found that learning reduces eIF2α phosphorylation in hippocampal excitatory neurons and a subset of hippocampal inhibitory neurons (those that express somatostatin, but not parvalbumin). Moreover, ablation of p-eIF2α in either excitatory or somatostatin-expressing (but not parvalbumin-expressing) inhibitory neurons increased general mRNA translation, bolstered synaptic plasticity and enhanced long-term memory. Thus, eIF2α-dependent mRNA translation controls memory consolidation via autonomous mechanisms in excitatory and somatostatin-expressing inhibitory neurons.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41586-020-2805-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7874887PMC
October 2020

Wolbachia influence on the fitness of Anagyrus vladimiri (Hymenoptera: Encyrtidae), a bio-control agent of mealybugs.

Pest Manag Sci 2021 Feb 24;77(2):1023-1034. Epub 2020 Oct 24.

Department of Entomology, ARO Newe Ya'ar Research Center, Ramat Yishay, Israel.

Background: Like numerous other animals, biocontrol agents (BCAs) of arthropod pests carry various microorganisms that may have diverse effects on the biology of their eukaryote hosts. We postulated that it is possible to improve the efficacy of BCAs by manipulating the composition of their associated microbiota. The parasitoid wasp Anagyrus vladimiri (Hymenoptera: Encyrtidae) from a mass-rearing facility was chosen for testing this hypothesis.

Results: High-throughput sequencing analysis indicated that fungal abundance in A. vladimiri was low and variable, whereas the bacterial community was dominated by the endosymbiont Wolbachia. Wolbachia was fixed in the mass-rearing population, whereas in field-collected A. vladimiri Wolbachia's prevalence was only approximately 20%. Identification of Wolbachia strains from the two populations by Multi Locus Sequence Typing, revealed two closely related but unique strains. A series of bioassays with the mass-rearing Wolbachia-fixed (W ) and a derived antibiotic-treated Wolbachia-free (W ) lines revealed that: (i) Wolbachia does not induce reproductive manipulations; (ii) W females have higher fecundity when reared individually, but not when reared with conspecifics; (iii) W females outcompete W when they share hosts for oviposition; (iv) longevity and developmental time were similar in both lines.

Conclusions: The findings suggest that W A. vladimiri have no clear fitness benefit under mass-rearing conditions and may be disadvantageous under lab-controlled conditions. In a broader view, the results suggest that augmentative biological control can benefit from manipulation of the microbiome of natural enemies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ps.6117DOI Listing
February 2021

Cellular Localization of Two Symbionts in the Digestive System and within the Ovaries of the Mirid Bug, .

Insects 2020 Aug 13;11(8). Epub 2020 Aug 13.

Department of Entomology, Newe-Ya'ar Research Center, ARO, Ramat-Yishay 30095, Israel.

Bacterial symbionts in arthropods are common, vary in their effects, and can dramatically influence the outcome of biological control efforts. (Heteroptera: Miridae), a key component of biological control programs, is mainly predaceous but may also display phytophagy. hosts symbiotic , which induce cytoplasmic incompatibility, and two species, and , which are found in all individuals tested. To test possible involvement of the two species in the feeding habits of , we first showed that the microbiome of the insect is dominated by these three symbionts, and later described the distribution pattern of the two species in its digestive system. Although both species were located in certain gut bacteriocyes, in caeca and in Malpighian tubules of both sexes, each species has a unique cellular occupancy pattern and specific distribution along digestive system compartments. Infrequently, both species were found in a cell. In females, both species were detected in the germarium, the apical end of the ovarioles within the ovaries, but not in oocytes. Although the cause for these distribution patterns is yet unknown, it is likely linked to host nutrition while feeding on prey or plants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/insects11080530DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7469188PMC
August 2020

Optimization of skeletal protein preparation for LC-MS/MS sequencing yields additional coral skeletal proteins in .

BMC Mater 2020 16;2. Epub 2020 Jul 16.

Marine Biology Department, University of Haifa, Haifa, Israel.

Stony corals generate their calcium carbonate exoskeleton in a highly controlled biomineralization process mediated by a variety of macromolecules including proteins. Fully identifying and classifying these proteins is crucial to understanding their role in exoskeleton formation, yet no optimal method to purify and characterize the full suite of extracted coral skeletal proteins has been established and hence their complete composition remains obscure. Here, we tested four skeletal protein purification protocols using acetone precipitation and ultrafiltration dialysis filters to present a comprehensive scleractinian coral skeletal proteome. We identified a total of 60 proteins in the coral skeleton, 44 of which were not present in previously published stony coral skeletal proteomes. Extracted protein purification protocols carried out in this study revealed that no one method captures all proteins and each protocol revealed a unique set of method-exclusive proteins. To better understand the general mechanism of skeletal protein transportation, we further examined the proteins' gene ontology, transmembrane domains, and signal peptides. We found that transmembrane domain proteins and signal peptide secretion pathways, by themselves, could not explain the transportation of proteins to the skeleton. We therefore propose that some proteins are transported to the skeleton via non-traditional secretion pathways.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s42833-020-00014-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7115838PMC
July 2020

Sponge microbiome stability during environmental acquisition of highly specific photosymbionts.

Environ Microbiol 2020 08 5;22(8):3593-3607. Epub 2020 Aug 5.

Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel.

In this study, we used in situ transplantations to provide the first evidence of horizontal acquisition of cyanobacterial symbionts by a marine sponge. The acquisition of the symbionts by the host sponge Petrosia ficiformis, which was observed in distinct visible patches, appeared several months after transplantation and at different times on different sponge specimens. We further used 16S rRNA gene amplicon sequencing of genomic DNA (gDNA) and complementary DNA (cDNA) and metatranscriptomics to investigate how the acquisition of the symbiotic cyanobacterium Candidatus Synechococcus feldmannii perturbed the diverse microbiota associated with the host P. ficiformis. To our surprise, the microbiota remained relatively stable during cyanobacterial symbiont acquisition at both structural (gDNA content) and activity (cDNA expression) levels. At the transcriptomic level, photosynthesis was the primary function gained following the acquisition of cyanobacteria. Genes involved in carotene production and oxidative stress tolerance were among those highly expressed by Ca. S. feldmannii, suggesting that this symbiont may protect itself and its host from damaging light radiation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/1462-2920.15165DOI Listing
August 2020

The Role of Land Use Types and Water Chemical Properties in Structuring the Microbiomes of a Connected Lake System.

Front Microbiol 2020 12;11:89. Epub 2020 Feb 12.

Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel.

Lakes and other freshwater bodies are intimately connected to the surrounding land, yet to what extent land-use affects the quality of freshwater and the microbial communities living in various freshwater environments is largely unknown. We address this question through an analysis of the land use surrounding 46 inter-connected lakes located within seven different drainage basins in northern Germany, and the microbiomes of these lakes during early summer. Lake microbiome structure was not correlated with the specific drainage basin or by basin size, and bacterial distribution did not seem to be limited by distance. Instead, land use within the drainage basin could predict, to some extent, NO + NO concentrations in the water, which (together with temperature, and total phosphorus) correlated to some extent with the water microbiome structure. Land use directly surrounding the water bodies, however, had little observable effects on water quality or the microbiome. Several microbial lineages, including Cyanobacteria and Verrucomicrobia, were differentially partitioned between the lakes. Significantly more data, including time-series measurements of land use and water chemical properties, are needed to fully understand the interaction between the environment and the organization of microbial communities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2020.00089DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7029742PMC
February 2020

Developmental transcriptomes of the sea star, Patiria miniata, illuminate how gene expression changes with evolutionary distance.

Sci Rep 2019 11 7;9(1):16201. Epub 2019 Nov 7.

Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, 31905, Israel.

Understanding how changes in developmental gene expression alter morphogenesis is a fundamental problem in development and evolution. A promising approach to address this problem is to compare the developmental transcriptomes between related species. The echinoderm phylum consists of several model species that have significantly contributed to the understanding of gene regulation and evolution. Particularly, the regulatory networks of the sea star, Patiria miniata (P. miniata), have been extensively studied, however developmental transcriptomes for this species were lacking. Here we generated developmental transcriptomes of P. miniata and compared these with those of two sea urchins species. We demonstrate that the conservation of gene expression depends on gene function, cell type and evolutionary distance. With increasing evolutionary distance the interspecies correlations in gene expression decreases. The reduction is more severe in the correlations between morphologically equivalent stages (diagonal elements) than in the correlation between morphologically distinct stages (off-diagonal elements). This could reflect a decrease in the morphological constraints compared to other constraints that shape gene expression at large evolutionary divergence. Within this trend, the interspecies correlations of developmental control genes maintain their diagonality at large evolutionary distance, and peak at the onset of gastrulation, supporting the hourglass model of phylotypic stage conservation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-019-52577-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6838185PMC
November 2019

Comparative Analysis of Intestine Microbiota of Four Wild Waterbird Species.

Front Microbiol 2019 20;10:1911. Epub 2019 Aug 20.

Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel.

Waterbirds are ubiquitous and globally distributed. Yet, studies on wild waterbirds' gut microbiota are still rare. Our aim was to explore and compare the gut microbial community composition of wild waterbird species. Four wild waterbird species that are either wintering or all-year residents in Israel were studied: great cormorants, little egrets, black-crowned night herons and black-headed gulls. For each bird, three intestinal sections were sampled; anterior, middle and posterior. No significant differences were found among the microbiota compositions in the three intestine sections of each individual bird. Each waterbird species had a unique microbial composition. The gut microbiota of the black-headed gulls' fundamentally deviated from that of the other bird species, probably due to a very high abundance (58.8%) of the genus (). Our results suggest a correlation between the waterbird species' phylogeny and their intestine microbial community hierarchical tree, which evinced phylosymbiosis. This recent coinage stands for eco-evolutionary patterns between the host phylogeny and its microbiota composition. We conclude that eco-evolutionary processes termed phylosymbiosis may occur between wild waterbird species and their gut microbial community composition.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2019.01911DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6711360PMC
August 2019

Possible cooption of a VEGF-driven tubulogenesis program for biomineralization in echinoderms.

Proc Natl Acad Sci U S A 2019 06 31;116(25):12353-12362. Epub 2019 May 31.

Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, 31905 Haifa, Israel;

Biomineralization is the process by which living organisms use minerals to form hard structures that protect and support them. Biomineralization is believed to have evolved rapidly and independently in different phyla utilizing preexisting components. The mechanistic understanding of the regulatory networks that drive biomineralization and their evolution is far from clear. Sea urchin skeletogenesis is an excellent model system for studying both gene regulation and mineral uptake and deposition. The sea urchin calcite spicules are formed within a tubular cavity generated by the skeletogenic cells controlled by vascular endothelial growth factor (VEGF) signaling. The VEGF pathway is essential for biomineralization in echinoderms, while in many other phyla, across metazoans, it controls tubulogenesis and vascularization. Despite the critical role of VEGF signaling in sea urchin spiculogenesis, the downstream program it activates was largely unknown. Here we study the cellular and molecular machinery activated by the VEGF pathway during sea urchin spiculogenesis and reveal multiple parallels to the regulation of vertebrate vascularization. Human VEGF rescues sea urchin VEGF knockdown, vesicle deposition into an internal cavity plays a significant role in both systems, and sea urchin VEGF signaling activates hundreds of genes, including biomineralization and interestingly, vascularization genes. Moreover, five upstream transcription factors and three signaling genes that drive spiculogenesis are homologous to vertebrate factors that control vascularization. Overall, our findings suggest that sea urchin spiculogenesis and vertebrate vascularization diverged from a common ancestral tubulogenesis program, broadly adapted for vascularization and specifically coopted for biomineralization in the echinoderm phylum.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1073/pnas.1902126116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6589685PMC
June 2019

Cascading effects on bacterial communities: cattle grazing causes a shift in the microbiome of a herbivorous caterpillar.

ISME J 2018 08 25;12(8):1952-1963. Epub 2018 Apr 25.

Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, 3498838, Israel.

Large mammalian herbivores greatly influence the functioning of grassland ecosystems. Through plant consumption, excreta, and trampling, they modify biodiversity, nutrient cycling, and soil properties. Grazing mammals can also alter soil and rhizosphere bacterial communities, but their effect on the microbiome of other animals in the habitat (i.e., insects) is unknown. Using an experimental field approach and Illumina MiSeq 16S rRNA gene sequencing, we analyzed the influence of cattle grazing on the microbial community of spring webworm caterpillars, Ocnogyna loewii. Our experimental setup included replicated grazed and non-grazed paddocks from which caterpillars were collected twice (first-second and fourth-fifth instar). The caterpillars' microbiome is composed mostly of Proteobacteria and Firmicutes, and contains a potential symbiont from the genus Carnobacterium (55% of reads). We found that grazing significantly altered the microbiome composition of late instar caterpillars, probably through changes in diet (plant) composition and availability. Furthermore, the microbiome composition of early instar caterpillars significantly differed from late instar caterpillars in 221 OTUs (58 genera). Pseudomonas and Acinetobacter were dominant in early instars, while Carnobacterium and Acinetobacter were dominant in late instars. This study provides new ecological perspectives on the cascading effects mammalian herbivores may have on the microbiome of other animals in their shared habitat.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41396-018-0102-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6052054PMC
August 2018

An exceptional family: Ophiocordyceps-allied fungus dominates the microbiome of soft scale insects (Hemiptera: Sternorrhyncha: Coccidae).

Mol Ecol 2017 Oct 14;26(20):5855-5868. Epub 2017 Sep 14.

Department of Biology and Environment, University of Haifa - Oranim, Tivon, Israel.

Hemipteran insects of the suborder Sternorrhyncha are plant sap feeders, where each family is obligately associated with a specific bacterial endosymbiont that produces essential nutrients lacking in the sap. Coccidae (soft scale insects) is the only major sternorrhynchan family in which obligate symbiont(s) have not been identified. We studied the microbiota in seven species from this family from Israel, Spain and Cyprus, by high-throughput sequencing of ribosomal genes, and found that no specific bacterium was prevalent and abundant in all the tested species. In contrast, an Ophiocordyceps-allied fungus sp.-a lineage widely known as entomopathogenic-was highly prevalent. All individuals of all the tested species carried this fungus. Phylogenetic analyses showed that the Ophiocordyceps-allied fungus from the coccids is closely related to fungi described from other hemipterans, and they appear to be monophyletic, although the phylogenies of the Ophiocordyceps-allied fungi and their hosts do not appear to be congruent. Microscopic observations show that the fungal cells are lemon-shaped, are distributed throughout the host's body and are present in the eggs, suggesting vertical transmission. Taken together, the results suggest that the Ophiocordyceps-allied fungus may be a primary symbiont of Coccidae-a major evolutionary shift from bacteria to fungi in the Sternorrhyncha, and an important example of fungal evolutionary lifestyle switch.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/mec.14332DOI Listing
October 2017