摘要
H oxa1 1基因是控制脊椎动物肢发育的重要基因 .根据人和鼠 H oxa1 1基因外显子 区和 区的保守序列设计了简并引物 ,采用 PCR法从热带爪蟾基因组 DNA中扩增和克隆到了H oxa1 1基因 ,并测定了核苷酸序列 .克隆的热带爪蟾 H oxa1 1基因片段长 1 598bp,由外显子 、内含子和外显子 三部分组成 ,其中外显子 60 4 bp,外显子 49bp.将该片段的核苷酸序列与人、鼠、斑马鱼 H oxa1 1基因的相应区域进行比较 ,发现该基因的内含子长度存在明显差异 .斑马鱼、热带爪蟾、鼠和人的内含子长度分别为 632 bp,945bp,1 42 1 bp和 1 41 2 bp,随动物进化阶梯的提高而变长 .外显子 区则高度保守 ,都是 49bp,外显子 区在长度上呈现约 1 0 %的变异 .将热带爪蟾 H oxa1 1基因编码的氨基酸序列与人、鼠、斑马鱼进行比较 ,它们之间分别有 67.0 %、66.5%和 46.0 %的同源性 .热带爪蟾与哺乳动物的同源性高于鱼类 ,可能反映了脊椎动物从鳍到肢的进化过程中 ,H oxa1 1基因经历了较多的变异 .
Hoxa 11 is a transcription factor,which plays a critical role in paired appendage development of vertebrates. Hoxa 11 gene from the frog( Xenopus tropicalis )was isolated by PCR using degenerate primers based on two highly conserved regions in exons Ⅰ and Ⅱ of Hoxa 11 genes of the human and mouse.The isolated gene fragment was cloned and sequenced. Hoxa 11 gene fragment from the frog is composed of 1 598 nucleotides:exon Ⅰ 604 bp,intron 945 bp and exon Ⅱ 49 bp.Compared the fragment with the corresponding regions of Hoxa 11 genes of the human,mouse and zebrafish,the result showed that intron was a changeable region.There was an evident increase in the length of intron from the zebrafish,frog to the mouse and human.Exon Ⅱ was a highly conserved region,and all four kinds of animals had 49 bp of exon Ⅱ.The exon Ⅰ region displayed about 10% variation in legnth.The deduced amino acid sequence of the frog shared 67.0%,66.5% and 46.0% homology respectively,with those of the human,mouse and zebrafish.The homology of amino acid sequences between the frog and mammal was higher than that between the frog and fish,which suggested that Hoxa 11 genes might have undergone a large mutation in the process of the fin limb transition.
出处
《中国生物化学与分子生物学报》
CAS
CSCD
北大核心
2001年第2期178-181,共4页
Chinese Journal of Biochemistry and Molecular Biology
基金
王宽诚教育基金&&
