【摘要】 miRNA(microRNA)是一类21～24个核酸长度的非编码小分子RNA(sRNA),它主要通过抑制或降解靶基因来调控植物生长发育等过程。试验利用在纤维长度上有显著差异的2个回交自交系BILs(Backcrossinbred lines)的0 DPA(Days post anthesis)、3 DPA的胚珠和10 DPA的纤维构建6个sRNA文库并进行Solexa测序。以已公布的棉花D5基因组序列和棉属其他序列为参考,经分析共发现561个miRNAs,其中包括254个已知的miRNAs(属于40个miRNA家族),75个候选的miRNAs和232个新的miRNAs,研究结果极大地丰富了棉属miRNAs。通过miRNA靶基因预测分析发现多数miRNAs负调控其对应的靶基因,少数正调控。KEGG(Kyoto encyclopedia of genes and genomes)注释结果表明miRNA的靶基因在植物激素代谢途径中显著富集。更多还原

【Abstract】 miRNAs(microRNAs) are 21-24 nt non-protein-coding small RNAs that play important roles in controlling plant growth and development by directing target mRNA cleavage or translational inhibition.In this study,we constructed libraries using ovules collected at 0 DPA(days post anthesis) and 3 DPA,and fibers collected at 10 DPA,from two interspecific backcross inbred lines(BILs).The libraries were sequenced and analyzed.There were significant differences in fiber length between the two lines,while other yield and fiber quality characters were similar.By comparison with the D5cotton genome and other known cotton sequences,we identified 561 miRNAs,including 254 conserved miRNAs,75 candidate conserved miRNAs,and 232 new miRNAs in the libraries.These data represent a large increase in the number of known cotton miRNAs.Most miRNAs act as negative regulators of their targets,and very few miRNAs are positive regulators.Analyses of target gene functions indicated that plant hormone metabolism was the main target for miRNAs.KEGG(Kyoto encyclopedia of genes and genomes) analysis indicates that miRNA target genes were significant enriched in plant hormone pathways.更多还原