Genome Reduction in Species within the Gut of an Amphipod from the Ocean's Deepest Point.

Citation data:

mSystems, ISSN: 2379-5077, Vol: 3, Issue: 3, Page: e00009-18

Publication Year:
Captures 14
Readers 14
Mentions 1
Blog Mentions 1
Social Media 6
Tweets 6
Repository URL:
Weipeng Zhang; Ren-Mao Tian; Jin Sun; Salim Bougouffa; Wei Ding; Lin Cai; Yi Lan; Haoya Tong; Yongxin Li; Alan J. Jamieson; Vladimir B. Bajic; Jeffrey C. Drazen; Douglas Bartlett; Pei-Yuan Qian; Morgan G. I. Langille Show More Hide
American Society for Microbiology
Immunology and Microbiology; Biochemistry, Genetics and Molecular Biology; Agricultural and Biological Sciences; Mathematics; Computer Science; Amphipod; Gut Microbiota; Mariana Trench; Psychromonas
Most Recent Tweet View All Tweets
Most Recent Blog Mention
article description
Amphipods are the dominant scavenging metazoan species in the Mariana Trench, the deepest known point in Earth's oceans. Here the gut microbiota of the amphipod Hirondellea gigas collected from the Challenger and Sirena Deeps of the Mariana Trench were investigated. The 11 amphipod individuals included for analyses were dominated by , of which a nearly complete genome was successfully recovered (designated CDP1). Compared with previously reported free-living strains, CDP1 has a highly reduced genome. Genome alignment showed deletion of the trimethylamine -oxide (TMAO) reducing gene cluster in CDP1, suggesting that the "piezolyte" function of TMAO is more important than its function in respiration, which may lead to TMAO accumulation. In terms of nutrient utilization, the bacterium retains its central carbohydrate metabolism but lacks most of the extended carbohydrate utilization pathways, suggesting the confinement of to the host gut and sequestration from more variable environmental conditions. Moreover, CDP1 contains a complete formate hydrogenlyase complex, which might be involved in energy production. The genomic analyses imply that CDP1 may have developed adaptive strategies for a lifestyle within the gut of the hadal amphipod H. gigas. As a unique but poorly investigated habitat within marine ecosystems, hadal trenches have received interest in recent years. This study explores the gut microbial composition and function in hadal amphipods, which are among the dominant carrion feeders in hadal habitats. Further analyses of a dominant strain revealed genomic features that may contribute to its adaptation to the amphipod gut environment. Our findings provide new insights into animal-associated bacteria in the hadal biosphere.