虾虎鱼科(Gobiidae)基因组微卫星DNA的分布特征

为了解虾虎鱼科(Gobiidae)鱼类基因组遗传结构特征，本研究自主开发矛尾复虾虎鱼(Synechogobius hasta)微卫星序列153条，结合从 GenBank 中筛选出的虾虎鱼科微卫星序列535条，合计686条微卫星序列，隶属于19种虾虎鱼，序列总长度为295062 bp，包含473个微卫星位点，微卫星位点累计长度为33370 bp。统计微卫星重复类型，发现在所有微卫星重复类型中以二碱基重复出现次数最多，位点数为361个，占总微卫星的76.32%，其中，重复拷贝类别最多的是 AC (340个)，占全部微卫星的71.88%，占二碱基重复微卫星的94.18%，在二碱基重复类型中没有发现 AT 和 GC 两种重复类型。三碱基重复位点数为35个，占总微卫星的7.4%，其中以 ACT 重复拷贝类别最多(12个)，占三碱基重复微卫星的34.29%。四碱基重复位点数为68个，其中以 CTAT 重复最多(31个)，占总微卫星的14.38%。五碱基重复类型中只有 TCTGG和 ATCTA 两种类型，只占全部微卫星的0.42%。六碱基重复7个，占总微卫星的1.48%，六碱基重复中各重复类型出现次数相当。在所有微卫星重复类型中没有发现单核苷酸重复类型。

Characteristic Analysis of Microsatellite DNA in the Genome of Gobiidae

The family Gobiidae is one of the largest fish families consisting of more than 200 genera and 2000 species. This family was found in near shore seawater, brackish water, and freshwater in the temperate and tropical areas all over the world. In this study we applied microsatellite DNA (short sequence repeat, SSR) to characterize the genetic structure of Gobiidae. We analyzed 153 SSR sequences amplified in our laboratory and 535 SSR sequences downloaded and screened from GenBank. The 686 sequences originated from 19 different species of Gobiidae. The total length of these sequences was about 295062 bp, in which 473 microsatellite repeat loci were found by using the bio-software Tandem Repeats Finder. The length of the repeat sequences was 33370 bp. We found that 361 dinucleotide repeat sequences accounted for the majority (76.32%) of the 473 repeat loci. Moreover, the AC repeat sequences were the most common (94.18) in the dinucleotide repeat sequences, whereas AT and GC repeat sequences were not observed. The number of the trinucleotide repeat sequences was 35 (7.4%), including 12 ACT repeat sequences that were the majority (34.29%). There were 68 tetranuleotide repeat sequences including 31 CTAT that was the dominant (14.38%). The numbers of both petranucleotide and hexanucleotide repeat sequences were 2 (0.42%) and 7 (1.48%) respectively. Intriguingly repeats of single nucleotide sequences were absent. Our results about the distribution of microsatellite contributed to a better understanding of the genomic structure of goby fish, and might provide important information for the development and application of goby fish microsatellite markers.