基于12SrRNA和16SrRNA序列的龟鳖类系统进化特征研究  

Phylogenetic characteristics of turtles based on 12S rRNA and 16S rRNA sequence

作　　者：刘海情[1] 刘楚吾[1] 刘丽[1] 

机构地区：[1]广东海洋大学水产学院,南海水产经济动物增养殖广东普通高校重点实验室,广东湛江524025

出　　处：《南方农业学报》2012年第11期1758-1764,共7页Journal of Southern Agriculture

基　　金：广东省科技计划项目(2010B020308004)

摘　　要：【目的】研究龟鳖类的系统进化关系,为龟鳖类资源的保护和合理开发利用提供理论依据。【方法】采用PCR扩增和测序的方法,获得小鳄龟(Chelydra serpentina)的12S rRNA和16S rRNA序列,分别结合NCBI中其他龟鳖的同源性序列进行比对分析;基于Kimura双参数模型计算龟鳖类种间、属间、科间的遗传距离;采用邻接(NJ)法、最大简约(MP)法和最大似然(ML)法构建分子系统进化树。【结果】经比对后得到394bp的12S rRNA一致序列和544bp的16SrRNA一致序列,二者合并得到938bp的联合序列。其中,可变位点327个,序列总变异率为34.9%,简约信息位点222个,单变异多态位点105个。T、C、A、G的平均含量分别为23.6%、24.1%、33.5%和18.7%,A+T含量为57.1%,G+C含量为42.8%。在327个可变位点中,转换数为61,颠换数为24,转换/颠换比率(R)为2.54。拟水龟属间的遗传距离为0.021～0.060,平均为0.467;淡水龟科8属之间的遗传距离为0.022～0.110,平均为0.0724;曲颈龟亚目7科(除平胸龟属外)间的遗传距离为0.071～0.123,平均为0.105。分子系统进化树显示,木纹龟属首先和陆龟科聚在一起,然后再与淡水龟科汇聚;中华花龟、大头乌龟与拟水龟属的成员相互镶嵌,聚成一支;鳄龟科、海龟科、棱皮龟科聚为一支;动胸龟科独成一支。【结论】应将龟亚科、淡水龟亚科提升为龟科、淡水龟科,并将大头乌龟、中华花龟并入拟水龟属,而平胸龟应从鳄龟科中分离出来,独立自成平胸龟科。Objective The experiment was conducted to analyze the phylogenetic relationships of terrapin in order to offer basic theoretical basis on terrapin resources protection and development.Method 12S rRNA and 16S rRNA sequences of Chelydra serpentina were obtained by using PCR amplification and sequencing.The homologous sequences of the other terrapins were downloaded from NCBI and analyzed together with the sequences of Chelydra serpentina.Inter-specific,inter-genus,and inter-family genetic distances were calculated based on the Kimura-2-parameter model,and the phylogenetic trees were constructed using the methods of neighbor joining（NJ）,maximum parsimony（MP）,and maximum likelihood（ML）.Result After alignment,394 bp consensus sequences of 12S rRNA and 544 bp consensus sequences of 16S rRNA were obtained,which merged together and became the 938 bp combined sequence.In the combined sequence,327 variable sites were detected,accounting for 34.9% of total sequences.Furthermore,there were 222 parsimony informative sites and 105 singleton sites.The average content of T,C,A,and G were 23.6,24.1,33.5,and 18.7%,respectively.The content of A＋T（57.1%） is greater than that of G＋C（42.8%）,and the ratio between transition and transversion was 2.53.The kimura-2-parameter distances between Mauremys ranged from 0.021 to 0.060,with an average measured at 0.467;the distances among 8 genus within Bataguridae ranged from 0.022 to 0.110,with an average measured at 0.0724;lastly,the distances among 7 families within Testudines（excluding Platysternon） were from 0.071 to 0.123,with an average value measured at 0.105.Phylogenetic tree analysis results suggested that Rhinoclemmys and Testudinidae should be clustered into one cataloge,then followed by Bataguridae.Ocadia sinensis and Chinemys megalocephala should be clustered into Mauremys all together.Chelydridae,Cheloniidae,and Dermochelyidae should be clustered into a single categary.Kinosternidae should be clustered into a category alone.Conclusion Chinemys megalocep

关 键 词：龟鳖类 12SrRNA 16SrRNA Kimura双参数遗传距离 系统进化树 

分 类 号：S917.4[农业科学—水产科学]