【摘要】 鲟形目鱼类9个物种线粒体基因组的基因组成高度保守,均编码37个基因,长度为16 438bp(达氏鲟)～16 760bp(欧洲鳇)。主编码链的A+T含量为53.3%(密苏里铲鲟)～54.6%(中华鲟和匙吻鲟)。9个蛋白质编码基因(atp6、atp8、cob、cox1、cox3、nad1、nad3、nad4和nad4L)编码氨基酸数目相同,分别为227、55、380、517、261、324、116、460和98个。15个主编码基因的差异位点分析表明,在鲟形目鱼类分子生态和群体遗传的研究中,nad5、nad4、cox1和cob基因是理想的分子标记,可用于分析其不同物种和群体之间的遗传多样性。在9种鲟形目鱼类中,遗传距离最小的是中华鲟与俄罗斯鲟(0.0070),遗传距离最大的是闪光鲟与白鲟(0.1777)。2个科之间的遗传距离远远大于科内部的遗传距离,因此支持传统的科级分类。基于线粒体基因组的系统发育结果表明,鲟形目鱼类分为2支:鲟科的7个物种和匙吻鲟科的2个物种分属2个类群(BPN=100,BPM=100,BPP=100),这与经典的系统分类观点一致。隶属于鲟属的中华鲟、俄罗斯鲟及闪光鲟与欧洲鳇聚类,支持率非常高(BPN=100,BPM=100,BPP=100),而将同为鲟属的高首鲟和达氏鲟排除在外,从而表明,线粒体基因组的数据支持将欧洲鳇并入鲟属。基于线粒体基因组数据支持鲟科内部的亲缘关系为:{[(中华鲟+俄罗斯鲟)+闪光鲟]+欧洲鳇}+(高首鲟+达氏鲟),密苏里铲鲟与它们关系最远。更多还原

【Abstract】 The gene content of mitochondrial genomes in nine sturgeons(37 genes encoded) in Acipenseriformes is highly conserved,and the lengths of nine mitochondrial genomes are changed from 16 438 bp(Acipenser dabryanus) to 16 760 bp(Huso huso).The A+T content of the heavy strand is varied from 53.3%(Scaphirhynchus albus) to 54.6%(A.sinensis and Polyodon spathula).The amino acid numbers in the nine protein coding genes(atp 6227,atp 855,cob 380,cox1 517,cox3 261,nad1 324,nad3 116,nad4 460 and nad4L 98) are identical.The genetic variation analysis of 15 main genes showed that nad5,nad4,cob and cox1 genes were ideal molecular markers in molecular ecology and genetic studies,which can be used to analysis of the genetic diversity among different species and groups.In mitochondrial genomes of nine sturgeons in Acipenseriformes,the genetic distance of A.sinensis and A.gueldenstaedtii was the minimum(0.0070),and that of A.stellatus and Psephurus gladius the maximum(0.1777).The genetic distance between two families was much larger than that within each family,which supports the traditional classification at the family level.The phylogenetic trees based on mitochondrial genomes showed that the order Acipenseriformes was divided into two clades:seven sturgeons and two paddlefishes belong to two separate groups,respectively(BPN=100,BPM=100,BPP= 100),which is identical to the traditional systematic classification viewpoint.Three Acipenser species(A.sinensis,A.gueldenstaedtii and A.stellatus) and H.huso were clustered with high support rate(BPN=100,BPM=100,BPP=100).Meanwhile,two Acipenser species(A.transmontanus and A.dabryanus) were excluded,indicating that the mitochondrial genome data support the inclusion of H.huso in the genus Acipenser.Mitochondrial genomic data support the relationship within Acipenseridae:{[(A.sinensis+ A.gueldenstaedtii) + A.stellatus]+H.huso}+(A.transmontanus + A.dabryanus) Were close relatives while S.albus was far from relatives.更多还原