Biology subjects

Roy, V.

Publications and source records attributed to Roy, V..

3 recordsLinked to original sources

bioRxiv2020

At each site its diversity: DNA barcoding reveals remarkable earthworm diversity in neotropical rainforests of French Guiana

Despite their recognized essential role in soil, earthworms in tropical environments are still understudied. The aim of this study was to re-evaluate the diversity at the regional scale, as well as to investigate the environmental and spatial drivers of earthworm communities. We sampled earthworm communities across a range of habitats at six locations in French Guiana using three different sampling methods. We generated 1675 DNA barcodes and combined them with data from a previous study. Together, all sequences clustered into 119 MOTUs which were used as proxy to assess species richness. Only two MOTUs were common between the six locations and 20.2 % were singletons, showing very high regional species richness and a high number of rare species. A canonical redundancy analysis was used to identify key drivers of the earthworm community composition. The RDA results and beta-diversity calculations both show strong species turnover and a strong spatial effect, resulting from dispersal limitations that are responsible for the current community composition. Sampling in different microhabitats allowed the discovery of 23 MOTUs that are exclusively found in decaying trunks and epiphytes, highlighting hidden diversity of earthworms outside of soil.

ecology↗

bioRxiv2020

Non-autonomous regulation of germline stem cell proliferation bysomatic MPK-1/MAPK activity in C. elegans

Extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) is a major positive regulator of cell proliferation that is often upregulated in cancer. Yet few studies have addressed ERK/MAPK regulation of proliferation within a complete organism. The C. elegans ERK/MAPK ortholog MPK-1 is best known for its control of somatic organogenesis and germline differentiation, but it also stimulates germline stem cell proliferation. Here we identify tissue-specific MPK-1 isoforms and characterize their distinct roles in germline function. The germline-specific MPK-1B isoform promotes germline differentiation, but has no apparent role in germline stem cell proliferation. By contrast, the soma-specific MPK-1A isoform promotes germline proliferation non-autonomously. Indeed, MPK-1A functions in the intestine or somatic gonad to promote germline proliferation, independently of its other known roles. We propose that a non-autonomous role of ERK/MAPK in stem cell proliferation may be conserved across species and other tissue types, with major clinical implications for cancer and other diseases.

developmental biology↗

bioRxiv2020

Integrated technology platform for accelerated discovery of antiviral antibody therapeutics

The emergence and reemergence of highly virulent viral pathogens with pandemic potential has created an urgent need for accelerated discovery of antiviral therapeutics. Antiviral human monoclonal (mAbs) are promising drug candidates to prevent or treat severe viral diseases, but the long timelines needed for discovery limits their rapid deployment and use. Here, we report the development of an integrated sequence of technologies incorporating advances in single-cell mRNA sequence analysis, bioinformatics, synthetic biology, and high-throughput functional analysis that allowed us to discover highly potent antiviral human mAbs and validate their activity in vivo at an unprecedented scale, speed, and efficiency. In a 78-day study, modeling deployment of a rapid response platform to an outbreak, we isolated >100 individual Zika virus (ZIKV) specific human mAbs, assessed their function, identified 29 broadly-neutralizing mAbs, and verified therapeutic potency of lead candidates with antibody-encoding mRNA formulation and/or IgG protein delivery in mice and nonhuman primates. Our work provides a roadmap for the rapid antibody discovery programs against viral pathogens of global concern.

immunology↗