红原鸡全基因组中微卫星分布规律研究

本文对红原鸡Gallus gallus全基因组中微卫星数量及分布规律进行了分析,查找到l～6个碱基重复类型的微卫星序列共282728个,约占全基因组序列(1.1Gb)的0.49%,分布频率为1/3.89kb,微卫星序列的长度主要在12～70个碱基长度范围内。第1、2、3条染色体上微卫星分布频率较高,而32号染色体上无微卫星分布。不同类型微卫星中,单碱基重复类型数目最多,为184192个,占总数的65.1%;其次是四、二、三、五、六碱基重复单元序列,分别占到总数的12.8%、9.7%、7.2%、4.6%、0.8%。T、A、AT、GTTT、AAAC、G、C、ATTT、AC、GT、AAAT、ATT、AAC、AAT、GTT、AG、CT、CTTT、AAAG、GTTTT、AAACA、AAGG、CCTT是红原鸡基因组中最主要的微卫星重复类型。本研究为红原鸡微卫星标记的分离筛选、遗传多样性的研究以及不同物种微卫星的比较分析奠定了基础。

Distribution Regularities of Microsatellites in the Gallus gallus Genome

Microsatellites of the entire genome in Gallus gallus were analyzed in this study. A total of 282 728 simple sequence repeats (SSRs) with 1~6 bp nucleotide motifs were identified, indicates that about 0.49% of the G. gallus genome was occupied by SSRs. And the frequency of SSR was 1/3.89 kb. The length of different microsatellites ranged mainly from 12 bp to 70 bp. Chromosome 1, 2 and 3 showed the maximum density of SSRs while the chromosome 32 had no SSR. In the different repeat types of the microsatellites, mononucleotide repeats (65.1%) motifs appeared to be the most abundant type, while the tetranucleotide, dinucleotide, trinucleotide, pentanucleotide and hexanucleotide repeats rates were 12.8%, 9.7%, 7.2%, 4.6% and 0.8%, respectively. In the G. gallus genome, T, A, AT, GTTT, AAAC, G, C, ATTT, AC, GT, AAAT, ATT, AAC, AAT, GTT, AG, CT, CTTT, AAAG, GTTTT, AAACA, AAGG, CCTT were the predominant repeat types. This study will certainly facilitate the isolation of microsatellites and the genetic diversity analysis of G. gallus, and build up the foundation for the comparative studies of microsatellites in different species.