芥菜型油菜A9染色体黄籽基因区域BAC重叠群的构建

A9染色体是芸薹属植物A基因组最长的染色体(序列约37 Mb),具有控制种子大小、种皮颜色、硫苷合成、油脂合成等重要性状的基因。利用芥菜型油菜A9染色体黄籽性状共分离标记A9-88和A9-32对已经构建的ZBjH BAC文库进行PCR步移筛选,共筛选出BAC 752个,测序395个,得到BAC末端序列674条,利用BAC末端序列设计引物533对,此外利用白菜已经公布的序列设计SSR引物38对、STS引物15对,构建了芥菜型油菜黄籽基因区域估算长约2.2 Mb的BAC重叠群。

Construction of BAC Contigs around the Yellow-seeded Locus of the Chromosome A9 in Brassica juncea

The chromosome A9,about 37Mbp in length,is the longest among A-genome chromosomes and carries genes for major agronomical traits,such as seed size,seed coat color,and glucosinolate and fat synthesis in Brassica species.Therefore,dissecting this chromosome is of great scientific and practical significance.In this study,the procedure of PCR walking was used to screen ZBjH BAC library with the markers A9-88 and A9-32 which was found to co-segregate with the yellow seed in A9 chromosome of B.juncea by our laboratory.752 BACs were screened out,395 of which were end sequenced,and resultant 674 BAC end sequences were used for further analysis.533 primer pairs were developed from these end sequences for next-round screen.In addition,38 SSR and 15 STS primer pairs were designed according to B.rapa sequence available in public data.The BAC contig(about 2.2 Mb) was constructed around the yellow seed coat gene on A9 chromosome in B.juncea.