甘蓝型油菜BnDMC1.A01基因的分离及序列分析

人工合成甘蓝型油菜是进行基因组学研究和种质资源创新的重要材料，但其减数分裂过程中经常出现异常，导致基因组遗传的不稳定和花粉育性的下降。DNA meiotic recombinase 1 （DMC1）是植物中控制减数分裂的重要基因，为了解油菜DMC1同源基因的序列及表达变异，本研究利用拟南芥和芸薹属作物DMC1同源基因的外显子保守序列设计引物，分离了常规和合成甘蓝型油菜（Brassica napus L.）A01染色体上的DMC1全长序列。氨基酸序列比对发现，BnDMC1.A01编码的蛋白具有植物中已报道的DMC1典型的保守结构域。分离了19个不同品系中BnDMC1.A01的基因序列，共划分为六种单倍型，发现第二外显子内存在两个导致氨基酸残基变异的SNP位点，该SNP位点在3种类型的油菜中均有分布。基因表达量分析发现，BnDMC1.A01在合成甘蓝型油菜中的表达量较常规油菜高，这些变异是否同人工合成甘蓝型油菜减数分裂异常有关还需进一步的研究验证。

Isolation and sequence analysis of meiotic gene BnDMC1.A01 in Brassica napus

Synthetic B. napus is an important type of materials for genomic research and germplasm improvement. But there are abnormalities in the process of meiosis which lead to genetic instability and pollen fertility decline in synthesized B. napus. For better understanding molecular mechanism of meiosis, sequence of DMC1 homologous, the important plants meiotic gene was isolated from B. napus. Primers were designed based on conserved cDNA sequences from homologous genes, and the DMC1 sequence on A01 chromosome was isolated from B. napus. The amino acid sequence alignment showed that BnDMC1.A01 encoded protein containng typical conserved domains of DMC1 had also been reported in rice and maize. At the same time, 6 haplotypes of the gene were obtained by sequencing analysis of BnDMC1.A01 in 19 accessions of B. napus; 2 SNPs resulted in mutation of amino acid residues were found and they distributed in all 3 types of B. napus. Gene expression showed that BnDMC1.A01 expression level in synthesized B. napus was higher than that in traditional B. napus. However, whether these variations in amino acid or gene expression cause abnormal meiosis in synthesized B. napus still need further elucidation.