摘要
生物多样性在染色体水平上的体现为染色体多样性,揭示了各属、种的所处环境不稳定,且两者密切相关。鱼类的染色体研究为反映其演化过程和分类地位提供了重要信息。研究裂腹鱼亚科(Schizothoracinae)的染色体组型,可以更好地了解其演化历史和适应性机制。在不同的环境中,物种为适应环境的变化,会表现出不同程度的遗传变异和表型多样性,但染色体形态保持相对稳定。裂腹鱼亚科鱼类是分布于高海拔地区的鲤科鱼类,染色体数目2n=50是最原始的染色体核型,随着海拔不断升高,染色体由原始核型变异。变异方式主要有多倍化(整个染色体组成倍增加)、罗伯逊易位(导致染色体数目非整倍的增加或减少)和染色体结构重排(引起染色体臂数的改变)。裂腹鱼亚科鱼类122种中已经确定染色体数、核型公式、染色体臂数(fundamental arm number,NF)的种类不足全部种类的30%。通过收集34种裂腹鱼亚科鱼类的染色体数(2n)、核型公式、NF及计算NF/2n值,从染色体核型特征、核型演化地位及倍性概述了其进化方式和适应性机制。结果表明,佩枯湖裸鲤(Gymnocypris dobula)染色体数目(2n=66)最少,双须叶须鱼(Ptychobarbus dipogon)染色体数目(2n>420)最多,大部分种染色体数目88~148,主要核型进化方式为四倍体化。染色体多样性广泛存在,有9种(包括亚种)具有2个染色体数及核型公式,这显示同种不同居群间染色体的差异。在遗传上有适应高原环境的潜在能力,随着特化等级的上升,染色体数表现出稳定的进化趋势。
Biodiversity reflected at the chromosomal level is called chromosomal diversity.It reveals the instability of various genera and species in their environments and highlights the close relationship between the two factors.Chromosome studies of fish provide us with important information about their evolutionary processes and taxonomic status.By studying the karyotype of Schizothoracinae,we may better understand their evolutionary history and adaptive mechanisms.In different environments,in order to adapt to environmental changes,species will show different degrees of genetic variation and phenotypic diversity,but the chromosome morphology remains relatively stable.Schizothoracinae are Cyprinidae fish distributed in high altitude areas.Chromosome number 2n=50 is the most primitive chromosome karyotype,and the chromosomes change from the primitive karyotype with increasing altitude.The main modes of variation are polyploidy(an increase in the composition of the entire chromosome),Robertson translocation(resulting in an increase or decrease in the number of chromosomes in aneuploidy),and chromosome structural rearrangement(resulting in a change in the number of chromosome arms).Of the 122 species within Schizothoracinae,less than 30%have determined their chromosome numbers,karyotypic formulas,and fundamental arm number(NF).In this study,we collected data on 34 species of Schizothoracinae,including their chromosome numbers,karyotypic formulas,NF,and calculated the NF/2n ratio.We summarized the evolutionary mechanisms and adaptive strategies from the perspective of chromosomal karyotypic characteristics,phylogenetic status of karyotypes,and ploidy levels.The results show that Gymnocypris dobula(2n=66)has the fewest chromosome numbers,while Ptychobarbus dipogon(2n>420)has the most.The majority of species have chromosome numbers ranging from 88 to 148,with the main karyotypic evolution being through tetraploidization.Chromosome diversity is widespread,and 9 species(including subspecies)have two different chromosome numbers and karyotypic formulas,indicating differences in chromosomes between different populations of the same species.Genetically,there is a potential ability to adapt to the plateau environment,and as the degree of specialization increases,the chromosome numbers show a stable evolutionary trend.
作者
苏麦耶·米尔阿迪力
程起群
MIERADILI Sumaiye;CHENG Qiqun(East China Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences,Shanghai 200090,China;College of Fisheries and Life Science,Dalian Ocean University,Dalian Liaoning 116023,China)
出处
《渔业信息与战略》
2025年第2期110-122,共13页
Fishery Information & Strategy
基金
国家自然科学基金项目(32273140)。
关键词
裂腹鱼亚科
染色体数目
核型公式
适应性机制
Schizothoracinae
chromosome number
karyotype formula
adaptive mechanism
