哺乳动物朊蛋白基因序列变异及其系统发育意义  

Prion Protein Gene(PRNP) Variation and its Phylogenetic Implications for Mammals

作　　者：管廷龙[1,2] 范振鑫[2] 曾博[2] 岳碧松[2] 邹方东[2] 

机构地区：[1]淄博市疾病预防控制中心,山东淄博255026 [2]生物资源与生态环境教育部重点实验室,四川大学生命科学学院,成都610064

出　　处：《四川动物》2010年第4期555-559,共5页Sichuan Journal of Zoology

摘　　要：以朊蛋白基因(PRNP)为研究对象,从GenBank中选取代表哺乳动物的17目61属共84个物种PRNP的编码区序列,分析了该基因的结构及其在不同层次分类阶元间的进化关系。发现由于在基因内序列重复区存在插入或缺失,PRNP的编码区长度在哺乳动物不同目的物种间存在差异。在终止密码子的使用上不同目的物种之间存在明显的偏好性,TGA和TAG是哺乳动物PRNP最常用的终止密码子,只有奇蹄目的5个种和有袋目袋鼠科的2个种是使用TAA终止。所有84条序列呈现了较高的核苷酸多样性(10.54%)。以PRNP为分子标记构建的系统进化树总体上是和以往研究一致的,结果表明PRNP可以应用于哺乳动物较高分类单元的系统进化研究,但对于能否用于种间和种内不能肯定。最后应用系统进化树对尚未有患病报道的哺乳动物的患病可能性进行了预测。Eighty-four prion protein gene （PRNP） sequences from 84 mammalian species belonging to 61 genera and 17 orders were analyzed in order to investigate its structure and differentiation among species. The lengths of PRNP coding sequences varied a lot among different species. In addition, TGA and TAG were the most widely used stop codons in mammalian PRNP, while TAA is only found in species of Perissodactyla and Marsupialia. Nucleotide diversity was high （ 10.54% ） among all 84 sequences. The reconstructed PRNP phylogenetic tree for all 84 species matches the results of traditional studies. Our analyses suggest that PRNP could be used as a molecular marker in phylogenetic studies of high level taxonomic units. Finally, we speculate on the possibility of different orders of mammals suffering from transmissible spongiform encephalopathies according to their phylogenetic relationships.

关 键 词：哺乳动物 朊蛋白基因 终止密码子 系统发育 

分 类 号：Q75[生物学—分子生物学]