@article{6c1b43658b3244f7ada8b1520e061f82,
title = "The genome of a subterrestrial nematode reveals adaptations to heat",
abstract = "The nematode Halicephalobus mephisto was originally discovered inhabiting a deep terrestrial aquifer 1.3 km underground. H. mephisto can thrive under conditions of abiotic stress including heat and minimal oxygen, where it feeds on a community of both chemolithotrophic and heterotrophic prokaryotes in an unusual ecosystem isolated from the surface biosphere. Here we report the comprehensive genome and transcriptome of this organism, identifying a signature of adaptation: an expanded repertoire of 70 kilodalton heat-shock proteins (Hsp70) and avrRpt2 induced gene 1 (AIG1) proteins. The expanded Hsp70 genes are transcriptionally induced upon growth under heat stress, and we find that positive selection is detectable in several members of this family. We further show that AIG1 may have been acquired by horizontal gene transfer (HGT) from a rhizobial fungus. Over one-third of the genes of H. mephisto are novel, highlighting the divergence of this nematode from other sequenced organisms. This work sheds light on the genomic basis of heat tolerance in a complete subterrestrial eukaryotic genome.",
author = "Weinstein, {Deborah J.} and Allen, {Sarah E.} and Lau, {Maggie C.Y.} and Mariana Erasmus and Asalone, {Kathryn C.} and Kathryn Walters-Conte and Gintaras Deikus and Robert Sebra and Gaetan Borgonie and {van Heerden}, Esta and Onstott, {Tullis C.} and Bracht, {John R.}",
note = "Funding Information: The authors acknowledge Laura Landweber, in whose laboratory J.R.B. prepared the H. mephisto Illumina DNA library. We thank Wei Wang, Jessica Wiggins, and Donna Storton of the Princeton Sequencing Core Facility for assistance with Illumina library preparation and sequencing. We also acknowledge Aaron Goldman for early work done on the H. mephisto project, and Elizabeth Ginsburg for comments on the paper. We thank Evgeny Bisk for assistance with the installation and troubleshooting of software on the Zorro Computer Cluster at American University. Mariana Erasmus acknowledges support from the Technology Innovation Agency (TIA), an agency of the Department of Science and Technology (DST) and is grateful to Izelle de Beer and Bernice Jordaan for their assistance in culturing of the nematodes. We are indebted to the logistical support of Sibanye Gold Limited, the management and staff of Beatrix Gold Mine that enabled the capture of H. mephisto and follow-up samples for metagenomic studies. The work of M.C.Y.L. was supported by NSF Grant #DEB-1441646 to T.C.O., and J.R.B. was supported by NIH 1K22CA184297 and a NASA DC Space Grant Consortium grant which funded the RNA and PacBio sequencing. Publisher Copyright: {\textcopyright} 2019, The Author(s).",
year = "2019",
month = dec,
day = "1",
doi = "10.1038/s41467-019-13245-8",
language = "English (US)",
volume = "10",
journal = "Nature Communications",
issn = "2041-1723",
publisher = "Nature Publishing Group",
number = "1",
}