无蹼壁虎6个鸟类Z染色体连锁基因的cDNA克隆和序列分析

cDNA Cloning and Sequence Analyses of Six Avian Z-Linked Genes from Peking Gecko(Gekko swinhonis)

利用RT-PCR技术从无蹼壁虎中获得了6个鸟类Z染色体连锁基因的cDNA片段序列。与铅山壁虎的同源基因序列相比，除CHD1-5＆#39;端序列中有3 bp的缺失外，其他基因序列均具有相同的核苷酸和氨基酸长度，且核苷酸序列和氨基酸序列的保守性均非常高（97%~100%）。在与有鳞目、龟鳖目和鳄目的其他已知序列比较时，发现6个基因的8个片段有不同程度的同源性，其中GHR基因的同源性最低，与该基因片段在进化分析中较高的ω值（ Ka/Ks）是一致的。性染色体连锁基因的克隆和染色体定位，将有助于进一步了解壁虎类甚至高等脊椎动物不同类型性染色体的起源和进化。

We sequenced partial cDNA sequences of the homologues of six avian Z-linked genes from Gekko swinhonis by using the RT-PCR approach. Comparing with those obtained from G. hokouensis, the lengths of all these fragments were identical at both nucleotide and amino acid levels except the 5’ region of CHD1,in which there had a deletion of 3 bp, furthermore,sequence similarity was very high （ 97% -100%） . When comparing with other exsiting sequences from Squamata,Testudines and Crocodylia, varying degrees of similarity was found in sequences of eight fragments from six genes. GHR showed the lowest homology,which was concerdant with the relatively high value of ω（Ka/ks）. Cloning and chromosomal location of the sex-chromosome linked genes will be helpful to elucidate the origins and evolutionary processes of different sex chromosomes in geckos or even in higher vertebrates.