Divergent paths in the evolutionary history of maternally transmitted clam symbionts
- 주제(키워드) symbiosis , reductive genome evolution , deep-sea , niche partitioning , selection
- 주제(기타) Biology
- 주제(기타) Ecology
- 주제(기타) Evolutionary Biology
- 설명문(일반) [Perez, Maeva; Angers, Bernard] Univ Montreal, Dept Biol Sci, Montreal, PQ, Canada; [Breusing, Corinna; Beinart, Roxanne A.] Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA; [Won, Yong-Jin] Ewha Womans Univ, Div EcoSci, Seoul, South Korea; [Young, C. Robert] Natl Oceanog Ctr, Southampton, England
- 등재 SCIE, SCOPUS
- OA유형 Green Accepted
- 발행기관 ROYAL SOC
- 발행년도 2022
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000190526
- 본문언어 영어
- Published As https://doi.org/10.1098/rspb.2021.2137
- PubMed https://pubmed.ncbi.nlm.nih.gov/35259985
초록/요약
Vertical transmission of bacterial endosymbionts is accompanied by virtually irreversible gene loss that results in a progressive reduction in genome size. While the evolutionary processes of genome reduction have been well described in some terrestrial symbioses, they are less understood in marine systems where vertical transmission is rarely observed. The association between deep-sea vesicomyid clams and chemosynthetic Gammaproteobacteria is one example of maternally inherited symbioses in the ocean. Here, we assessed the contributions of drift, recombination and selection to genome evolution in two extant vesicomyid symbiont clades by comparing 15 representative symbiont genomes (1.017-1.586 Mb) to those of closely related bacteria and the hosts' mitochondria. Our analyses suggest that drift is a significant force driving genome evolution in vesicomyid symbionts, though selection and interspecific recombination appear to be critical for maintaining symbiont functional integrity and creating divergent patterns of gene conservation. Notably, the two symbiont clades possess putative functional differences in sulfide physiology, anaerobic respiration and dependency on environmental vitamin B12, which probably reflect adaptations to different ecological habitats available to each symbiont group. Overall, these results contribute to our understanding of the eco-evolutionary processes shaping reductive genome evolution in vertically transmitted symbioses.
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