Gene discovery by SSH analysis of Ms2 isogenic lines of wheat.

摘要

Wheat has a complex and large genome compared to rice. The characterization of the expressed portion of wheat genome is the choice of strategies in discovering wheat genes. To identify genes associated with nuclear male sterility of wheat, suppressionsubtractive hybridization (SSH) was performed using RNA from young spikelets of a pair of Ms2 isogenic lines around the meiotic stage. A SSH library was constructed with more than 900 clones. Dot and colony hybridization using cDNA of fertile and sterile young anthers as probes showed over 80% of the cloned inserts were present only in the sterile lines. Twelve unique ESTs were isolated from this library and sequenced. Blast analysis showed that some of them only showed similarity to sequences derivedfrom Triticeae species. However, when they were used as probes in hybridization to DNA of T. aestivum, H villosa, rice and maize, hybridization signal was observed for almost all probes and all species used. Full-length cDNA has been obtained for some ofthem by RACE-PCR or by library screening. Some of these ESTs were mapped to wheat chromosome groups by nulli-tetrasomic analysis.