基于Roche 454 GS FLX高通量测序的叶城沙蜥基因组微卫星特征分析

叶城沙蜥Phrynocephalus axillaris是我国特有的一种小型爬行动物,广泛分布于新疆塔里木盆地、吐鲁番-哈密盆地和甘肃敦煌盆地。本研究利用Roche 454 GS FLX高通量测序技术进行叶城沙蜥微卫星位点筛选,获得了91 190条高质量序列。用Krait搜索微卫星位点,共得到1～6个碱基重复类型的完美型微卫星序列29 890个。不同类型微卫星中,单碱基重复类型数目最多,有14 630个,占总数的48. 95%,其次是二碱基,约占28. 60%,四碱基、三碱基、五碱基和六碱基分别占10. 73%、10. 48%、0. 92%和0. 32%。二碱基微卫星中AC重复类型数量最多,三碱基、四碱基、五碱基和六碱基中分别是ATC、AAAT、AAAAT和AATCCC。叶城沙蜥完美型微卫星中数量最多的11种重复拷贝类型分别为C、A、AC、AG、AAAT、ATC、AT、AAT、ATAG、AGG和AAC。本研究深化了对叶城沙蜥基因组的了解,并为以后开发和筛选大量高质量微卫星标记提供了数据支持,也为利用微卫星标记研究叶城沙蜥种群遗传结构和谱系地理模式奠定了基础。

Characterization of Microsatellites in Phrynocephalus axillaris Genome Using Roche 454 GS FLX

Yarkand toad-headed agama( Phrynocephalus axillaris),a small reptile endemic to China,is widely distributed in Tarim Basin,Turpan-Hami Basin,Xinjiang Uygur Autonomous Region and Dunhuang Basin,Gansu province.The whole genome of P.axillaris was sequenced using Roche 454 GS FLX platform,and 91 190 high quality sequences were obtained.A total of 29 890 simple sequence repeats with 1-6 bp nucleotide motifs were identified by Krait.Among the different repeat types of the microsatellites,mononucleotide( 48.95%) was the most common repeat unit,followed by the di-( 28.60%),tetra-( 10.73%),tri-( 10.48%),penta-( 0.92%) and hexanucleotides( 0.32%).AC,ATC,AAAT,AAAAT,and AATCCC were the most common repeat units among the di-,tri-,tetra-,penta-,and hexanucleotides,respectively.In the genome of P.axillaris,there were 11 predomiant repeat types,which included C,A,AC,AG,AAAT,ATC,AT,AAT,ATAG,AGG and AAC.This study contributes to the understanding of the genetic feature for P.axillaris,and will provide data support for development and screening of high quality microsatellite markers.In addition,this study lays a foundation for further revealing the population genetic structure and phylogeographic pattern of this lizard using microsatellite markers.