Isolation and analysis of differentially expressed genes in dominant genic male sterility (DGMS) Brassica napus L

摘要

Dominant genic male sterility (DGMS) is an important approach to utilize the heterosis of Brassica napus. It can be presumed that male sterility is caused by the abnormity of the male gametogenesis. This study was undertaken to compare the genes that were differentally expressed between the fertile and sterile plants of the homozygous DGMS two-type line Rs 1046AB, as an initial step towards understanding the molecular mechanism of DGMS and male gametogenesis. In this study, SSH was used to construct two subtracted libraries for enriching genes that were up-regulated in the fertile plants or sterile ones, and then a customed cDNA microarray with the clones of two subtracted libraries on it, was used to profile global gene expression patterns. cDNA clones showing a ±2.0-fold change in expression signal were regarded as up- or down- regulated. A total of 1200 significantly differentially expressed clones were isolated between the fertile and sterile plants, Northern blot further demonstrated the credibility of the microarray data. Subsequently, about 400 clones were selected for sequencing, and they represented 216 unigenes. Of these genes, 181 homologous sequences could be divided into 17 groups excluding those that encode the unclassified proteins, genes involved in metabolism; cell rescue, defense and virulence; biogenesis of cellular components and protein fate were the four largest groups, possessed 11.11%, 7.69%, 6.55% and 5.70% respectively; in contrast, genes related to protein activity regulation occupied the smallest proportion (0.9%). And the other 35 genes had no homology in the databases at the National Center for Biotechnical Information (NCBI), so including the 81 genes belonged to the unclassified proteins, there were totally 115 (54.2%) genes function unknown or novel genes. Furthermore, some important pathways related to male gametogenesis were found by using the program of KOBAS, such as nitrogen metabolism, nitrobenzene degradation, and starch and sucrose metabolism. Further analyses of the results are still in progress.