Rancurel, C. | Search bioRxiv

bioRxiv2018

Family-Companion: analyse, visualise, browse, query and share your homology clusters

Identifying homology groups in predicted proteomes from different biological sources allows biologists to address questions as diverse as inferring species-specific proteins or retracing the phylogeny of gene families. Nowadays, command-line software exists to infer homology clusters. However, computing and interpreting homology groups with this software remains challenging for biologists and requires computational skills.\n\nWe propose Family-Companion, a web server dedicated to the computation, the analysis and the exploration of homology clusters. Family-Companion aims to fill the gap between analytic software and databases presenting orthologous groups based on a set of public data. It offers a user-friendly interface to launch or upload precomputed homology cluster analysis, to explore and share the results with other users. The exploration of the results is highly facilitated by interactive solutions to visualize proteome intersections via Venn diagrams, phylogenetic trees, multiple alignments, and also by querying the results by blast or by keywords.\n\nFamily-Companion is available at http://family-companion.toulouse.inra.fr with a demo dataset and a set of video tutorials. Source code and installation protocol can be found at https://framagit.org/BBRIC/family-companion/. A container-based package simplifies the installation of the web-suite.

bioinformatics↗

bioRxiv2017

Signatures of the evolution of parthenogenesis and cryptobiosis in the genomes of panagrolaimid nematodes

Most animal species reproduce sexually, but parthenogenesis, asexual reproduction of various forms, has arisen repeatedly. Parthenogenetic lineages are usually short lived in evolution; though in some environments parthenogenesis may be advantageous, avoiding the cost of sex. Panagrolaimus nematodes have colonised environments ranging from arid deserts to arctic and antarctic biomes. Many are parthenogenetic, and most have cryptobiotic abilities, being able to survive repeated complete desiccation and freezing. It is not clear which genomic and molecular mechanisms led to the successful establishment of parthenogenesis and the evolution of cryptobiosis in animals in general. At the same time, model systems to study these traits in the laboratory are missing.\n\nWe compared the genomes and transcriptomes of parthenogenetic and sexual Panagrolaimus able to survive crybtobiosis, as well as a non-cryptobiotic Propanogrolaimus species, to identify systems that contribute to these striking abilities. The parthenogens are most probably tripoids originating from hybridisation (allopolyploids). We identified genomic singularities like expansion of gene families, and selection on genes that could be linked to the adaptation to cryptobiosis. All Panagrolaimus have acquired genes through horizontal transfer, some of which are likely to contribute to cryptobiosis. Many genes acting in C. elegans reproduction and development were absent in distant nematode species (including the Panagrolaimids), suggesting molecular pathways cannot directly be transferred from the model system.\n\nThe easily cultured Panagrolaimus nematodes offer a system to study developmental diversity in Nematoda, the molecular evolution of parthenogens, the effects of triploidy on genomes stability, and the origin and biology of cryptobiosis.

evolutionary biology↗