Unveiling an ancient whole-genome duplication event in Stentor, the model unicellular eukaryotes  

作　　者：Weibo Zheng Chao Li Zhaorui Zhou Xiao Chen Michael Lynch Ying Yan 

机构地区：[1]School of Life Sciences,Ludong University,Yantai 264025,China [2]Key Laboratory of Evolution&Marine Biodiversity(Ministry of Education),and Institute of Evolution&Marine Biodiversity,Ocean University of China,Qingdao 266003,China [3]Biodesign Center for Mechanisms of Evolution,Arizona State University,Tempe AZ 85287,USA [4]Marine College,Shandong University,Weihai 264209,China

出　　处：《Science China(Life Sciences)》2025年第3期825-835,共11页中国科学(生命科学英文版)

基　　金：supported by the Science & Technology Innovation Project of Laoshan Laboratory(LSKJ202203203);the National Science Foundation of China (32270558);the National Institutes of Health Grant (R35-GM122566-01);the National Science Foundation (DEB-1927159, DBI-2119963);the Moore and Simons Foundations (735927);the Young Taishan Scholar Program of Shandong Province;the Project of Outstanding Young Innovative Team in Higher Education Institutions of Shandong Province (2023KJ038).

摘　　要：Whole-genome duplication(WGD)events are widespread across eukaryotes and have played a significant role in moulding the genetic architectures of diverse organisms.In the present study,the newly sequenced genome of a giant ciliated protist,Stentor roeselii,provides an opportunity for the analysis of the collinearity and retention of reciprocal best-hit genes between two Stentor species.As a main result,we have unveiled a previously undetected ancient WGD event shaping the genome of its congener,Stentor coeruleus,a model protist used in cytological and evolutionary studies.Genomes of two congeners,S.coeruleus and S.roeselii,are compared and analyzed,revealing that:(i)the former exhibits a much higher retention rate of colinear-gene pairs(28%)than does S.roeselii,and in S.coeruleus,75%of genes that have a RBH hit in S.roeselii,have paralogs with high amino-acid identity,consistent with a WGD event in the lineage leading to S.coeruleus;(ii)the S.roeselii genome possesses extremely short intergenic regions,implying that the lengths of intergenic regions are under strong selection;(iii)the unique characteristics of introns may have been shaped in the common ancestor of heterotrichs;(iv)gene families that play a role in activities of multiple protein kinases and voltage-gated ion channels expanded rapidly in the ancestor of both taxa,possibly relating to the remarkable regenerative ability in Stentor.This study offers new insights into the evolutionary dynamics of ciliate genomes,with implications for understanding of the processes underlying the evolution of genomic complexity.

关 键 词：genome complexity CILIATES whole-genome duplication Stentor 

分 类 号：R37[医药卫生—病原生物学]