大熊猫及其近种活化素基因β_A亚基成熟肽序列的克隆分析及其在分类地位上的应用  

Molecular Cloning of the DNA Sequence of Activin β_A Subunit Gene Mature Peptides from Panda and Related Species and Its Application in the Research of Phylogeny and Taxonomy

作　　者：汪晓晶[1] 王小行[1] 王亚军[1] 王喜忠[1] 何光昕[2] 陈红卫[2] 费立松[2] 

机构地区：[1]四川大学生命科学学院细胞室,成都610064 [2]成都市动物园,成都610081

出　　处：《Acta Genetica Sinica》2002年第9期782-786,共5页

基　　金：成都大熊猫繁育研究基金会资助 (项目编号 990 11)~~

摘　　要：借鉴互联网中已经克隆到的Activin基因 βA 亚基成熟肽序列 ,设计并合成 1对兼并引物 ,利用PCR技术从大熊猫、小熊猫、马来熊的基因组DNA中直接扩增目的基因片段 ,并分别克隆到大肠杆菌载体pBlueScript+ 当中 ,然后对培养产物进行序列测定。DNA序列分析表明 ,三种物种的Activin基因 βA 亚基成熟肽序列长度均为 35 9bp ,无内含子。基因片段编码一个含有 119个氨基酸残基的肽段。大熊猫、小熊猫、马来熊在该成熟肽核苷酸和氨基酸序列上表现出高度的同源性 ,其中核苷酸同源性为 93.9% ,氨基酸同源性高达 99%以上。此外 ,3种动物的核酸限制性酶切图谱也高度相似。与GenBank中收录的其他物种Activin基因 βA 亚基成熟肽序列相比较 ,显示此片段在处于不同进化程度的物种之间仍具有高度保守性。运用系统发育与进化树软件包PHILIP ,并结合克隆序列对大熊猫、小熊猫、马来熊进化与分类地位进行了探讨。采用不同的统计学分析方法 ,所得到的 3个物种系统发育进化树的拓扑结构完全一致。相比较而言 ,大熊猫与马来熊有着较近的亲缘关系 ,而小熊猫与上述两个物种的亲缘关系相对疏远。结果支持将大熊猫与马来熊归为熊科、而将小熊猫单列成科的学术观点。这是首次以生殖相关的核基因作为研究对象 。Activin, which is included in the transforming growth factor β (TGF β ) superfamily of proteins and receptors,is known to have broad ranging effects in the creatures. The mature peptide of β A subunit of this gene,one of the most highly conserved sequence,can elevate the basal secretion of follicle stimulating hormone (FSH) in the pituitary and FSH is pivotal to organism's reproduction. Reproduction block is one of the main reasons which cause giant panda to extinct. The sequence of Activin β A subunit gene mature peptides has been successfully amplified from giant panda,red panda and malayan sun bear's genomic DNA by using polymerase chain reaction (PCR) with a pair of degenerate primers. The PCR products were cloned into the vector pBlueScript + of Esherichia coli . Sequence analysis of Activin β A subunit gene mature peptides shows that the length of this gene segment is the same (359bp) and there is no intron in all three species. The sequence en codes a peptide of 119 amino acid residues. The homology comparison demonstrates 93.9% DNA homology and 99% homology in amino acid among these three species. Both GenBank blast search result and restriction enzyme map reveal that the sequences of Activin β A subunit gene mature peptides of different species are highly conserved during the evolution process. Phylogeny analysis is performed with PHYLIP software package. A consistent phylogeny tree has been drawn with three different methods. The software analysis outcome accords with the academic view that giant panda has a closer relationship to the malayan sun bear than the red panda. Giant panda should be grouped into the bear family ( Uersidae ) with the malayan sun bear. As to the red panda,it would be better that this animal be grouped into the unique family (red panda family) because of great difference between the red panda and the bears ( Uersidae ).

关 键 词：大熊猫 近种 活化素基因βA亚基成熟肽 克隆分析 分类地位 应用 序列分析 系统发育 

分 类 号：Q959.8[生物学—动物学]