Lineage-specific trait variations and plasticity of obligate parthenogenetic animals following the expansion of distribution range to a continental archipelago  

作　　者：Xiao-Fei Tian Maki Toyota Hajime Ohtsuki Jotaro Urabe 

机构地区：[1]Fishery College,Zhejiang Ocean University,Zhoushan,316022 China [2]Aquatic Ecology Laboratory,Graduate School of Life Sciences,Tohoku University,Senda,980-8578 Japan [3]Institute of Freshwater Biology,Nagano University,Ueda,386-0031 Japan

出　　处：《Journal of Systematics and Evolution》2024年第4期775-784,共10页植物分类学报（英文版）

基　　金：supported by the Province Key Research and Development Program of Zhejiang(2021C02047);a MEXT Scholarship by the Japanese Government to Xiaofei Tian,the Japan Society for the Promotion of Science(JSPS)Grant-in-Aid for Scientific Research(KAKENHI)15H02642,16H02522,and 20H03315;the Environment Research and Technology Development Fund by the Ministry of Environment,Japan(4-2103)to Jotaro Urabe.

摘　　要：Evolutionary theory suggests the hypothesis that among genetically isolated populations,phenotypic variation should be smaller in populations with smaller ratios of nonsynonymous to synonymous substitutions(dN/dS)because smaller dN/dS ratios occur under greater purification selections.Two distinct lineages(JPN1 and JPN2)of panarctic Daphnia cf.pulex sensu Hebert(1995),invaded independently into Japan from North America,provide an excellent opportunity to test this hypothesis because the earlier invader JPN1 has a lower dN/dS ratio than JPN2.Therefore,we examined phenotypic variations in fitness-related traits,including digestive,life-history,and morphological traits,among several genotypes within these two lineages.We found that phenotypic variations were smaller within the JPN1 lineage than within the JPN2 lineage.Furthermore,within-lineage variation of the phenotypic plasticity to changing food levels was smaller in the JPN1 lineage than in the JPN2 lineage.These results support the hypothesis that the JPN1 lineage has been more efficiently subjected to negative selection.However,the magnitude of the phenotypic plasticity of these traits was,on average,at the same level between the JPN1 and JPN2 lineages and its direction differed among genotypes of these lineages,suggesting that the JPN2 genotypes might have exploited niches that were different from those of the JPN1 genotypes.

关 键 词：asexual animal genetic variation invasion organism phenotypic plasticity phenotypic trait ZOOPLANKTON 

分 类 号：Q94[生物学—植物学]