一个水稻雄配子不育基因MGA1(t)的遗传及表达特征分析

在水稻转基因材料后代中筛选到一个自交后代标记基因呈1:1异常分离的雄配子不育突变体(暂命名为Male gametophyte abortion1,mga1(t))。该突变体花粉约50%败育,花粉败育表型与T-DNA共分离,且只能通过雌配子传递,表明mga1(t)是一个T-DNA插入引起的雄配子败育突变体。Southern blot分析表明,mga1(t)为单拷贝T-DNA插入突变体。侧翼序列分析发现T-DNA插入在水稻3号染色体上一个Bax inhibitor(BI)-1 like家族蛋白基因的5’非翻译区,该基因可能与细胞程序性死亡有关。RT-PCR表达分析显示MGA1(t)基因在水稻不同生长发育期均有表达,尤其在长度发育为0～7mm的颖花中强表达,表明该基因是一个水稻雄配子优势表达基因。

Genetic and Expression Analyses of a Male Sterile Gene MGA l(t) in Rice (Oryza sativa L.)

A male gamete sterile mutant(tentatively named Male gametophyte abortion1,mga1(t)) was obtained by abnormality screening of transgenic rice materials.The ratio of marker gene segregation was 1:1 by χ2-test and the pollen grains of the mutant were half sterile.The phenotype of pollen abortion was found co-segregating with T-DNA insertion in mga1(t) mutant,and T-DNA passed only through the female gamete.Southern blot analysis indicated that T-DNA inserted into the genome of the mutant was single copy.Flanking sequence analysis showed that T-DNA was inserted into the 5’ untranslated region of a Bax inhibitor(BI)-1 like family protein gene in rice chromosome 3.BI-1 like protein gene was predicted to be involved in programmed cell death.RT-PCR expression analyses revealed that MGA1(t) gene expressed during the whole growth and development stages of rice,and had strong expression pattern in the spikelets with length about 0～7 mm.These results indicated that MGA1(t) gene was an male-preferential expressed gene.