林麝全基因组微卫星分布规律研究

Distribution Regularity of Microsatellites in Moschus berezovskii Genome

林麝Moschus berezovskii是中国重要的资源动物,也是国家Ⅰ级重点保护野生动物。本研究使用生物信息学方法,分析林麝全基因组中完美型微卫星的分布特征。在林麝2.53 Gb的基因组序列中,共搜索到665 524个完美型微卫星,总长度为11 517 784 bp,占基因组序列总长度的0.42%,总丰度为244个/Mb。林麝基因组中,单碱基微卫星序列数量最多,为221 058个,约占总微卫星数的33.22%,丰度为81.05个/Mb,然后依次为二碱基、五碱基、三碱基、四碱基、六碱基重复类型微卫星。林麝基因组中数目最多的10种微卫星类别依次为:A、AACTG、AGC、AC、AT、AG、AAAT、AAC、AAT和AAAC,占所有基因组微卫星的93.2%,表现出明显的A、T偏好。林麝基因组微卫星序列分布研究表明,其在外显子(2 530个)上的分布数量远低于内含子(200 906个)和基因间隔区(454 596个),与前人关于微卫星在非编码区的分布多于编码区的结论一致。本研究为深入研究林麝基因组特征及筛选更多优良微卫星标记提供了基础数据。

Forest musk deer（ Moschus berezovskii） is a critically endangered species. Perfect microsatellite number and distribution regularity of microsatellites in forest musk deer genome were analyzed by microsatellite search tool. A repertoire of 665 524 perfect SSRs with 1-6 bp nucleotide motifs accounting for 0. 42% of forest musk deer genome（ 2. 53 Gb） were scanned,and the abundance of microsatellites was 244 no./Mb. Mono-nucleotide was the most abundant category with the highest relative abundance（ 81. 05 no./Mb）,accounting for 33. 22% of all the SSRs,followed by di-nucleotide（ 21. 68%）,pentra-nucleotide（ 21. 09%）,tri-nucleotide（ 18. 08%）,tetra-nucleotide（ 5. 86%）,and hexa-nucleotide（ 0. 09%）. The most abundant microsatellite repeats in forest musk deer genome were A,AACTG,AGC,AC,AT,AG,AAAT,AAC,AAT,and AAAC,totally accounting 93. 2% of the scanned microsatellites and showed an apparent A and T preference.The number of microsatellites located on the coding sequences（ n = 2 530） was less than that on the non-coding sequence such as introns（ n = 200 906） and intergenic regions（ n = 454 596）,and this was consistent with previous studies. This study provides adequate material for the future study of forest musk deer.