利用Cyt b基因序列研究翘嘴红鲌的系统发生

线粒体细胞色素b基因序列分析可显示种间及种内遗传差异，广泛用于种类鉴定和系统发生研究。为了阐明翘嘴红鲌与其他鳊亚科鱼类的亲缘关系，扩增并测定了翘嘴红鲌的414bp细胞色素b基因片段序列。所获序列与4种鳊亚科鱼类细胞色素b基因的相应序列进行比较，发现共有61个多态性核苷酸位点（14．73％），大多数位点出现在密码子的第3位且主要为碱基转换。翘嘴红鲌与鳊之间的序列同源性最高，为93．48％，与广东鲂、三角鲂和团头鲂的序列同源性则分别为90．58％，90．82％，91．30％。以鲤为外群，分别利用MP法和NJ法分析上述序列数据，获得相似的系统发生树。该结果显示，翘嘴红鲌和鳊聚为1个支系，广东鲂、三角鲂以及团头鲂则聚为另1个支系，说明翘嘴红鲌与鳊的亲缘关系较近，而与广东鲂、三角鲂及团头鲂的亲缘关系则较远。

PHYLOGENETIC RELATIONSHIP OF ERYTHROCULTER ILISHAEFORMIS WITH OTHER FOUR ABRAMIDINAE SPECIES BASED ON CYTOCHROME b GENE SEQUENCES

A 414-bp fragment of Cytochrome b gene from Erythroculter ilisshaeformis was PCR amplified and sequenced.Alignment of this fragment with the sequences of other 4 Abramidinae species revealed 61 polymorphic nucleotide sites(14.73% of the total),most of which were base transitions and occurred at the third position of the codons.The sequence homology of E.ilisshaeformis to Parabramis pekinesis,Megalobrama hoffmanni,M.terminalis and M.amblycephala was 93.48%,90.58%,90.82% and 91.30%,respectively.After the sequence data were analyzed by the methods of maximum parsimony and neighbor-joining,using Cyprinus carpio as an outgroup species,two similar phylogenetic trees were obtained.Based on the trees,E.ilisshaeformis and P.pekinesis were clustered into one clade and the other 3 species into another,thus indicating that E.ilisshaeformis shared a closer relationship to P.pekinesis than to Megalobrama hoffmanni,M.terminalis and M.amblycephala.