为了明确菠菜EST序列中SSR的总体特点,开发菠菜EST-SSR引物;为利用EST-SSR引物进行菠菜性别相关特异序列的克隆奠定基础,本文从NCBI上获得1093条EST,利用在线软件SSRIT检测所含SSR序列,并进行分析。共检索出68条SSR序列,分布于64条EST中,检出率为6.22%,包括22种重复基元。其中二核苷酸重复基元的EST-SSR占主导地位,占总SSR数目的32.3%。利用在线引物设计软件Primer3.0设计了7对EST-SSR引物,在适合的PCR反应体系下,分别以雌、雄菠菜DNA基因组为模板,对设计的EST-SSR引物进行筛选,结果显示以EST序列HS097148设计的一对引物从菠菜雌雄基因组中扩增出一条雄性特异的条带,表明通过菠菜EST-SSR引物获得菠菜性别相关特异序列是可行的。
The objective of this study was to characterize spinach SSRs derived from ESTs and to develop EST-SSR markers for possible use of the markers in the studies of cloning sex-specific fragment from spinach (Spinacia oleracea L.). 1 093 ESTs of spinach were obtained from NCBI database, which were detected and analyzed by on-line software SSRIT. 68 SSR sequences were obtained, distributing throughout 64 ESTs. The frequency of these EST-SSRs was 6.22%, including 22 dominant type repeat unit. Among them, dinucleotide repeats was dominant, account for 32.3% of all SSR sequences. 7 pairs of EST-SSR primers were designed by on-line software Primer 3.0. The designed EST-SSR primers were screened with optimal PCR condition based on the male and female spinach genomic DNA as template respectively. Results showed that a pair of primer derived from ETS HS097148 could amplify a male specific band, indicating that a possible method to clone sex-specific fragment from spinach was established through developing EST-SSR marker from spinach EST database.