Molecular characterization of an anther-preferential gene from rice

Expression levels of anther-expressed genes in rice were estimated by plaque hybridization. A total of 33 cDNAs, isolated randomly from an anther-enriched cDNA library, were used as probes to hybridize both anther and leaf cDNAs. The expression level of individual cDNA clones was then estimated by counting the number of plaques hybridized to each probe. Based on abundance patterns that appeared in both anther and leaf cDNA libraries, the clones were classified into three groups. This classification showed that the majority of the clones (one group) exhibited expression in both cDNA libraries at almost equal frequency. The other two groups showed either low or no expression in the leaf cDNA library. Among the cDNA clones,RA1003 (detected only in the anther cDNA library) was selected and further characterized at the molecular level. Consistent with the results of the plaque hybridization experiment, northern blot analysis also revealed no gene expression in vegetative organs, leaves, or roots. However, expression was high in the flowers, especially in the anthers. Detailed molecular studies of the gene are also described and discussed here.