Genome analysis of <I>Plectus murrayi</I>, a nematode from continental Antarctica

TitleGenome analysis of Plectus murrayi, a nematode from continental Antarctica
Publication TypeJournal Article
Year of Publication2021
AuthorsXue, X, Suvorov, A, Fujimoto, S, Dilman, AR, Adams, B
JournalG3 Genes|Genomes|Genetics
Date Published01/2021
Keywordsgene loss, genome architecture, genome assembly, genome decay, Plectus murrayi

Plectus murrayi is one of the most common and locally abundant invertebrates of continental Antarctic ecosystems. Because it is readily cultured on artificial medium in the laboratory and highly tolerant to an extremely harsh environment, Plectus murrayi is emerging as a model organism for understanding the evolutionary origin and maintenance of adaptive responses to multiple environmental stressors, including freezing and desiccation. The de novo assembled genome of Plectus murrayi contains 225.741 million base pairs and a total of 14,689 predicted genes. Compared to Caenorhabditis elegans, the architectural components of Plectus murrayi are characterized by a lower number of protein-coding genes, fewer transposable elements, but more exons, than closely related taxa from less harsh environments. We compared the transcriptomes of lab-reared Plectus murrayi with wild-caught Plectus murrayi and found genes involved in growth and cellular processing were up-regulated in lab-cultured Plectus murrayi, while a few genes associated with cellular metabolism and freeze tolerance were expressed at relatively lower levels. Preliminary comparative genomic and transcriptomic analyses suggest that the observed constraints on P. murrayi genome architecture and functional gene expression, including genome decay and intron retention, may be an adaptive response to persisting in a biotically simplified, yet consistently physically harsh environment.