【摘要】 微卫星是近年大力开发的一种遗传标记,为推进按蚊遗传学相关研究,对按蚊全基因组中由1～6个碱基重复单元组成的简单序列重复(微卫星) 进行了分析. 进而对其微卫星的丰度和分布进行了比较分析,也比较了染色体各个区域(外显子、内含子和基因间隔区) 之间的分布差异. 微卫星在按蚊基因组中的比例约占2.14%,其中X染色体拥有微卫星的密度最大. 对按蚊基因组中微卫星丰度而言,A碱基和C碱基重复在基因组中丰度相似,AC单元的丰度是AG单元的两倍多,然而AT和CG单元非常稀少;对于三四碱基而言,AGC,AAAC和AAAT单元最为丰富,ACG,ACT,AGG,CCG,ATGC,CCCG,ACTG,AACT,ACGT,AGAT,CCGG,ACCT和AGCT单元等均很稀少,而一些五碱基重复,在某条甚至某几条染色体中均未分布.除两碱基重复单元在2L的外显子区域丰度较高外,其他重复单元均在内含子和基因间隔区丰富. 进一步分析显示,微卫星在每条染色体两臂的丰度和分布存在着很多的相似性.更多还原

【Abstract】 Microsatellite is a genetic marker, explored recently. In order to improve related studies on genetics of Anopheles gambiae, simple sequence repeats of the entire mosquito genome with 1~6 bp nucleotide motifs were analyzed. Abundance and distribution of microsatellites across the A.gambiae genome were analyzed and compared between various (exons, introns and intergenic) regions of all the chromosomes. About 2.14% of the mosquito genome was occupied by SSRs. Chromosome X had the maximum density of SSRs. Abundance of A repeats was similar to C repeats. AC was a little more than two times as abundant much as AG. However, AT and CG repeats were rare. For tri- and tetramer repeats, AGC, AAAC and AAAT predominated while ACG, ACT, AGG, CCG, ATGC, CCCG, ACTG, AACT, ACGT, AGAT, CCGG, ACCT and AGCT were rare. For some pentamer repeats, one was completely absent on a certain chromosome, even on several chromosomes. SSRs in exons of all chromosomes were less abundant than in introns and intergenic regions except for mono- and dimer repeats in exons of chromosome 2L. Abundance and distribution of SSRs on the two arms of each chromosome showed much in common.更多还原