Biology subjects

Rivera-Vicens, R. E.

Publications and source records attributed to Rivera-Vicens, R. E..

4 recordsLinked to original sources

bioRxiv2022

rRNA depletion for holobiont metatranscriptome profiling across demosponges

Despite the extensive knowledge of sponge microbiome diversity, a critical knowledge gap persists concerning the molecular mechanisms that govern host-symbiont interactions. Deciphering these mechanisms is crucial for understanding how sponge holobionts respond to environmental changes and identifying potential disruptions in sponge-microbe associations. A hindrance to progress in characterizing these molecular crosstalk mechanisms is the scarcity of broadly applicable molecular methods for efficiently sequencing meta-transcriptomes across a diverse array of sponge species. To tackle this challenge, we have introduced a hybrid-capture strategy capable of selectively depleting sponge and bacterial rRNA from total RNA extracts obtained from highly divergent demosponges with varying microbiome complexities. Our innovative pan-demosponge rRNA depletion approach streamlines the efficient characterization of metatranscriptomes within diverse demosponge holobionts, concurrently facilitating the quantification of gene expression in both the host and its microbiome. This methodological advancement represents a significant stride in unraveling the molecular intricacies of sponge-microbe interactions, providing a robust platform for future investigations across a broad spectrum of sponge species.

genomics↗

bioRxiv2021

Transcriptomic response of Cinachyrella cf. cavernosa sponges to spatial competition

Spatial competition in the intertidal zones drives the community structure in marine benthic habitats. Organisms inhabiting these areas not only need to withstand fluctuations of temperature, water level, pH, and salinity, but also need to compete for the best available space. Sponges are key members of the intertidal zones, and their life history processes (e.g. growth, reproduction, and regeneration) are affected by competition. Here we used transcriptomics to investigate the effects of interspecific competition between the tetillid sponge Cinachyrella cf. cavernosa, the zoantharid Zoanthus sansibaricus, and the macroalgae Dictyota ciliolata. The analysis of differentially expressed genes showed that Z. sansibaricus was the most stressful competitor to C. cf. cavernosa, which showed an increased rate of cellular respiration under stress of competition. Similarly, an up-regulation of energy metabolism, lipid metabolism, and the heat-shock protein (HSP) 70 was also observed along with an indication of a viral infection and decreased ability to synthesise protein. A down-regulation of purine and pyrimidine metabolism indicated reduction in physiological activities of the competing sponges. Moreover, a putative case of possible kleptocnidism, not previously reported in Cinachyrella cf. cavernosa was also observed. This study opens the door for more detailed investigations of marine organisms competing for spatial resources using transcriptome data.

ecology↗

bioRxiv2021

TransPi - a comprehensive TRanscriptome ANalysiS PIpeline for de novo transcriptome assembly

The use of RNA-Seq data and the generation of de novo transcriptome assemblies have been pivotal for studies in ecology and evolution. This is distinctly true for non-model organisms, where no genome information is available. Nevertheless, studies of differential gene expression, DNA enrichment baits design, and phylogenetics can all be accomplished with the data gathered at the transcriptomic level. Multiple tools are available for transcriptome assembly, however, no single tool can provide the best assembly for all datasets. Therefore, a multi assembler approach, followed by a reduction step, is often sought to generate an improved representation of the assembly. To reduce errors in these complex analyses while at the same time attaining reproducibility and scalability, automated workflows have been essential in the analysis of RNA-Seq data. However, most of these tools are designed for species where genome data is used as reference for the assembly process, limiting their use in non-model organisms. We present TransPi, a comprehensive pipeline for de novo transcriptome assembly, with minimum user input but without losing the ability of a thorough analysis. A combination of different model organisms, k-mer sets, read lengths, and read quantities were used for assessing the tool. Furthermore, a total of 49 non-model organisms, spanning different phyla, were also analyzed. Compared to approaches using single assemblers only, TransPi produces higher BUSCO completeness percentages, and a concurrent significant reduction in duplication rates. TransPi is easy to configure and can be deployed seamlessly using Conda, Docker and Singularity.

bioinformatics↗

bioRxiv2020

The genomic basis of animal origins: a chromosomal perspective from the sponge Ephydatia muelleri

The genomes of non-bilaterian metazoans are key to understanding the molecular basis of early animal evolution. However, a full comprehension of how animal-specific traits such as nervous systems arose is hindered by the scarcity and fragmented nature of genomes from key taxa, such as Porifera. Ephydatia muelleri is a freshwater sponge found across the northern hemisphere. Here we present its 326 Mb genome, assembled to high contiguity (N50: 9.88 Mb) with 23 chromosomes on 24 scaffolds. Our analyses reveal a metazoan-typical genome architecture, with highly shared synteny across Metazoa, and suggest that adaptation to the extreme temperatures and conditions found in freshwater often involves gene duplication. The pancontinental distribution and ready laboratory culture of E. muelleri make this a highly practical model system, which with RNAseq, DNA methylation and bacterial amplicon data spanning its development and range allows exploration of genomic changes both within sponges and in early animal evolution.

evolutionary biology↗