摘要
以生长于不同气候条件下的 17个拟南芥核心生态型为材料 ,分析了它们的抗旱转录因子CBF4基因区域的序列多态性。结果表明 :拟南芥CBF4基因区域具有高密度的单核苷酸多态性 (SNP)和插入缺失 (Indel) ,多态性频率为每 35 8bp一个SNP ,每 14 3bp一个Indel,基因非编码区的多态性是编码区的 4倍 ;在编码区 ,SNP的频率为每 96 4bp一个SNP ,其中发现 2 5av、2 0 3av和 2 4 4av 3个生态型CBF4基因区域 10 34位 (以GenBank登录号AB0 15 4 78序列第 196 96位的核苷酸为 1)碱基变化 :G T ,引起第 2 0 5位氨基酸变化 :gly val。核苷酸多样性统计分析显示 ,该基因内部大范围内存在连锁不平衡 (linkagedisequilibrium ,LD) ,5′端非编码区有一个重组。与拟南芥等的研究结果类似 ,选择压力对不同的区域作用不同。 3′端非编码区核苷酸多样性程度最高 ,是平衡性选择的结果 ,编码区核苷酸变化符合中性突变假说 ,而
Intraspecific nucleotide polymorphism in the drought induced transcription factor CBF4 region of Arabidopsis thaliana was analyzed with 17 core accessions growing in different ecoclimate.High density of single nucleotide polymorphism ( SNP ) and insertion/deletion ( Indel ) were found,on average 1 SNP per 35.8 bp and 1 Indel per 143 bp.Nucleotide polymorphism in non-coding region was three times higher than that in coding region.In coding region of CBF4,SNP frequency is one SNP per 96.4 bp,one nonsynonymous mutation was detected from 25 av,203 av and 244 av accessions,which is the 205th site amino acid variation: glyval caused by the 1 034th site (corresponding to 19 696 site nucleotide of GenBank No.AB015478 as 1) nucleotide variation : GT.Statistical result of nucleotide diversity showed that linkage disequilibrium (LD) existed in large-scale region of CBF4 and recombination event was also detected in 5′non-coding region.Identical to the results of other genes of Arabidopsis,different regions of the gene were seemingly under different selective pressures.Balancing selection resulted in high nucleotide diversity in 3′non-coding region,and the neutral mutation hypothesis can explain the DNA polymorphism in coding region,whereas,nature positive selection in the population affected nucleotide variation in 5′non-coding region of gene.
基金
北京市科委科技基金 (编号 :H0 12 0 10 2 40 2 40 113
H0 2 0 82 115 0 13 0 )
科技部中法PRA(编号 :中法PRABT0 2 2 )
国家重大基础研究规划项目 (编号 :2 0 0 3CB114 3 0 0 )资助~~
