Biology subjects

Verdes, A.

Publications and source records attributed to Verdes, A..

5 recordsLinked to original sources

bioRxiv2024

The archaeal class Nitrososphaeria is a key player of the reproductive microbiome in sponges during gametogenesis

Sponge-associated microbes play fundamental roles in regulating their hosts physiology, yet their contribution to sexual reproduction has been largely overlooked. Most studies have concentrated on the proportion of the microbiome transmitted from parents to offspring, providing little evidence of the putative microbial functions during gametogenesis in sponges. Here, we use 16S rRNA gene analysis to assess whether the microbial composition of five gonochoristic sponge species differs between reproductive and non-reproductive individuals and correlate these changes with their gametogenic stages. In sponges with mature oocytes, reproductive status did not influence either beta or alpha microbial diversity. Interestingly, in two of the studied species, Geodia macandrewii and Petrosia ficiformis, which presented oocytes at the previtellogenic stage, significant microbial composition changes were detected between reproductive and non-reproductive individuals. These disparities were primarily driven by differentially abundant taxa affiliated with the Nitrososphaeria archaeal class in both species. We speculate that the previtellogenic stages are more energetically demanding, leading to microbial changes due to the phagocytosis of microbes to meet nutritional demands during this period. Supporting our hypothesis, we observed significant transcriptomic differences in G. macandrewii, mainly associated with the immune system, indicating potential changes in the sponges recognition system. Overall, we provide the first insights into the possible roles of sponge microbiomes during reproductive periods, potentially uncovering critical interactions that support reproductive success.

microbiology↗

bioRxiv2024

Towards the identification of the molecular toolkit involved in scale worm bioluminescence (Polinoidae, Annelida)

BackgroundBioluminescence, or the ability of a living organism to produce light, has evolved independently in numerous taxa inhabiting a panoply of ecosystems, although it is more frequent among marine animals. Scale worms are a group of marine polynoid annelids characterized by having dorsal scales, known as elytra, capable of emitting bioluminescent light by a mostly unknown molecular mechanism that may involve a photoprotein called polynoidin. Here, we used RNA-seq data to characterize the expression of genes potentially involved in light production in the polynoid species Harmothoe imbricata (Linnaeus, 1767) and Harmothoe areolata (Grube, 1860) across tissues of the specimens. We also compared the transcriptomes of the selected species with other bioluminescent and non-bioluminescent polynoids, to identify shared orthologous genes potentially involved in light production. In addition, we investigated the disposition of the photocytes on the elytra using confocal microscopy and histological analyses. ResultsOur results showed a total of 16 candidate genes, 15 orthologous genes and 12 enriched GO terms potentially involved in bioluminescence, including genes related with oxidative stress, cytoskeleton, nervous system, stress response, wounding response, eye constituents and metabolic pathways. We also confirmed the presence of photocytes in both species, which appeared distributed around the elytrophore. ConclusionsAmong the genes found potentially implicated in bioluminescence we suggest that the oxidoreductase protein, peroxidasin, could be a polynoidin candidate since it appears overexpressed in the elytra of both species and it is located in the endoplasmic reticulum, where this photoprotein has been described to be found.

evolutionary biology↗

bioRxiv2023

Drivers of species knowledge across the Tree of Life

Knowledge of biodiversity is unevenly distributed across the Tree of Life. In the long run, such disparity in awareness unbalances our understanding of life on Earth, influencing policy decisions and the allocation of research and conservation funding. We investigated how humans accumulate knowledge of biodiversity by searching for consistent relationships between scientific (number of publications) and societal (number of views in Wikipedia) interest, and species-level morphological, ecological and socio-cultural factors. Across a random selection of 3,019 species spanning 29 Phyla/Divisions, we show that socio-cultural factors are the most important correlates of scientific and societal interest in biodiversity, including the fact that a species is useful or harmful to humans, has a common name and is listed in the IUCN Red List. Furthermore, large-bodied, broadly distributed and taxonomically unique species receive more scientific and societal attention, whereas colorfulness and phylogenetic proximity to humans correlates exclusively with societal attention. These results highlight a favoritism towards limited branches of the Tree of Life, and that scientific and societal priorities in biodiversity research broadly align. This suggests that we may be missing out on key species in our research and conservation agenda simply because they are not on our cultural radar.

ecology↗

bioRxiv2018

Delegating Sex: differential gene expression in stolonizing syllids uncover the hormonal control of reproduction in Annelida

Stolonization in syllid annelids is a unique mode of reproduction among animals. During the breeding season, a structure resembling the adult but containing only gametes, called stolon, is formed at the posterior end of the animal. When the stolons mature, they detach from the adult and the gametes are released into the water column. The process is synchronized within each species, and it has been reported to be under environmental and endogenous control, probably via endocrine regulation. To further understand the reproduction in syllids and to elucidate the molecular toolkit underlying stolonization, we generated Illumina RNA-seq data from different tissues of reproductive and non-reproductive individuals of Syllis magdalena, and characterized gene expression during the stolonization process. Several genes involved in gametogenesis (ovochymase, vitellogenin, testis-specific serine/threonine-kinase), immune response (complement receptor 2), neuronal development (tyrosine-protein kinase Src42A), cell proliferation (alpha-1D adrenergic receptor), and steroid metabolism (hydroxysteroid dehydrogenase 2) were found differentially expressed in the different tissues and conditions analyzed. In addition, our findings suggest that several neurohormones, such as methyl farnesoate, dopamine and serotonin, might trigger the stolon formation, the correct maturation of gametes and the detachment of stolons when gametogenesis is complete. The process seems to be under circadian control, as indicated by the expression patterns of r-opsins. Overall, our results shed light into the genes that orchestrate the onset of gamete formation, and improve our understanding of how some hormones, previously reported to be involved in reproduction and metamorphosis processes in other invertebrates, seem to also regulate reproduction via stolonization.

molecular biology↗

bioRxiv2018

Molecular phylogeny of Odontosyllis (Annelida, Syllidae): A recent and rapid radiation of marine bioluminescent worms.

Marine worms of the genus Odontosyllis (Syllidae, Annelida) are well known for their spectacular bioluminescent courtship rituals. During the reproductive period, the benthic marine worms leave the ocean floor and swim to the surface to spawn, using bioluminescent light for mate attraction. The behavioral aspects of the courtship ritual have been extensively investigated, but little is known about the origin and evolution of light production in Odontosyllis, which might in fact be a key factor shaping the natural history of the group, as bioluminescent courtship might promote speciation. To investigate the speciation patterns and evolutionary history of Odontosyllis and to trace the origin of bioluminescence within the group, we inferred phylogenies using both gene concatenation and multispecies coalescent species-tree approaches with a multilocus molecular dataset (18S rRNA, 16S rRNA and COI). We also used this dataset to estimate divergence times and diversification rates in a relaxed molecular clock Bayesian framework. Our results suggest that Odontosyllis has undergone a recent rapid radiation, possibly triggered by the origin of bioluminescent courtship, which might have increased speciation rates and lineage divergence through sexual selection. Additionally, our analyses reveal that the genus Odontosyllis as currently delineated is a paraphyletic group that needs to be reorganized to reflect evolutionary relationships.

evolutionary biology↗