香菇三个功能基因部分序列的单核苷酸多态性分析

SNP analysis of the fragments of three functional genes of the mushroom Lentinula edodes

以15个香菇栽培品种为材料,对尿嘧啶核苷酸-胞嘧啶核苷酸激酶基因(UMP-CMP kinase gene,uck1)、分裂原活化蛋白激酶基因(mitogen-activated protein kinase gene,mapk)和外切β-1,3葡聚糖酶基因(exo-β-1,3-glucanase-encoding gene,exg1)进行了部分序列的单核苷酸多态性(single nucleotide polymorphism,SNP)分析。结果表明,测序中出现的双峰,是菌丝双核体细胞中两细胞核之间的差异造成的。在采用uck1、mapk和exg1的3,126bp中,共发现48处多态性位点,发生频率为1/65bp,其中36个属于转换、12个为颠换。从群体发生频率上,38个属于超过10%的常见SNP,10个属于罕见SNP。不同基因的SNP发生频率不同,uck1、mapk和exg1的SNP发生频率分别为1.40%、0.82%和2.41%。外显子区SNP数量高于内含子,3个基因在外显子区域分布28个,内含子分布20个。外显子的28个SNP位点中,11个为错义突变,17个为同义突变。错义突变引起了编码氨基酸的改变。对SNP位点的聚类分析表明,15个栽培品种间存在的多态性位点在1–36之间,15个品种的SNP类型不同。uck1,mapk,exg1的SNP可用于香菇栽培品种的鉴别。

Abstract： The single nucleotide polymorphism （SNP） was analyzed for the fragments of three functional genes, i.e. UMP-CMP kinase gene, uckl, mitogen-activated protein kinase gene, mapk and exo-β-1,3-glucanase-encoding gene, exgl for 15 cultivars of the Shiitake mushroom Lentinula edodes. The double peaks appeared in the sequencing cbromatograms werefound due to the presence of heterokaryotic nuclei in the dikaryotic cells. A total of 48 SNPs were detected at a frequency of 1/65bp from 3,126bp length of uckl, mapk and exgl genes. There were 36 transition mutations and 12 transversion mutations in the 48 SNPs. On the population frequency, there were 38 common SNPs （above 10% occurrence frequency） and 10 rare SNPs. The SNP frequency was different in the genes： 1.40% for uckl, 0.82% for mapk, and 2.41% for exgl. There were more SNPs detected in the exons （28 SNPs） than introns （20 SNPs）. Among the 28 SNPs in the exons, 11 were non-synonymous mutations caused corresponding change of coded amino acids and 17 were synonymous mutations. There were 1-36 polymorphic SNP loci in the 15 cultivars and specific SNP type was present in every cultivar of L. edodes so that SNP of uckl, mapk and exgl could be used to distinguish the cultivars of the Shiitake mushroom.