牦牛基因组串联重复序列(AC)n/(GT)n的分离  

Isolation of simple tandem repeats(AC)n/(GT)n from genome of yak

作　　者：蔡欣[1,2] 泽让东科[3] 张修月[1] 贾小东[1] 岳碧松[1] 

机构地区：[1]四川大学生命科学学院、四川省濒危动物保护生物学重点实验室、教育部生物资源与生态环境重点实验室,四川成都610064 [2]西南科技大学生命科学与工程学院,四川绵阳621010 [3]西南民族大学生命科学与技术学院,四川成都610041

出　　处：《中国兽医学报》2012年第9期1289-1294,共6页Chinese Journal of Veterinary Science

基　　金：中国博士后科学基金资助项目(20090461336);中国博士后科学基金特别资助项目(201003703)

摘　　要：采用Dynal磁珠-生物素标记的(AC)12探针和牦牛基因组MboⅠ酶切片段杂交,富集牦牛基因组(AC)n/(GT)n串联重复序列并构建基因文库,阳性克隆率达到61.1%。通过对176个阳性克隆的测序获得含有(AC)n/(GT)n重复的序列92条,其中连续型重复序列40条(占43.48%),间断型41条(占44.57%),复合型11条(占11.96%)。从92条序列中又筛选出重复次数大于10次的(AC)n/(GT)n序列59条。相对连续型重复序列,牦牛基因组中间断型重复序列所占比率并没有显著上升,可以推测牦牛自身基因组DNA损伤修复能力的适应性进化水平较高,足以承受高海拔地区强紫外线导致的基因组核苷酸替换突变等自然选择压力。本研究从牦牛基因组分离的全新(AC)n/(GT)n重复序列将在牦牛品种/类群内遗传结构分析、品种/类群之间遗传关系研究以及牦牛个体/群体生产或适应性性状的分子标记研究等方面具有重要应用价值。The researches on yak genetics and breeding were extremely restricted due to lacking of reliable DNA mo- lecular markers. Oligonucleotide （AC）12 -probes attached to streptavadin coated magnetic beads （Dynal） were hy- bridized with DNA fragments obtained from digestion of yak genome by Mbo I ~ The simple tandem repeats （AC）n/ （GT）n in yak genome, were enriched by Dynal magnetic beads and the gene libraries containing （AC）n/（GT）n were constructed. The percentage of positive clones confirmed by PCR was 61.1 ~//0 and 92 out of 176 positive clones were detected to contain （AC）n/（GT）n sequences. Among the 92 sequences,40 were perfect tandem repeats （43.48~//oo）, 41 were imperfect repeats （44. 570/00） and 11 were compound repeats （11.96~）. Moreover,59 sequences with more than 10 repeats of （AC）n/（GT）n motifs were screened from the 92 sequences. As compared with the percentage of perfect repeats of （AC）n/（GT） n, no significant increases of imperfect repeats were observed in yak genome. Therefore,we deduced that the level of adaptive evolution of the ability to repair damaged genomic DNA of yaks were high enough to endure the nature pressure of nucleotide substitution resulted from ultraviolet irradiation in high-altitude areas. In one words,the newly isolated （AC）n/（GT）n repeats from yak genome will display their val- ues in examining intra population genetic structure and inter- population relationships, and investigating molecular markers for production and adaptive traits of individual/population.

关 键 词：牦牛 简单串联重复 磁珠分离 

分 类 号：S813.3[农业科学—畜牧学] Q78[农业科学—畜牧兽医]