Characterization of cDNAs induced in meiotic prophase in lily microsporocytes.

To identify and analyze genes functioning during reproductive cell formation in higher plants, cDNAs harboring the messages induced in meiotic prophase were isolated and characterized. A cDNA library constructed from microsporocytes in meiotic prophase of Lilium longiflorum was screened with a subtraction probe specific to meiotic prophase. Clones selected were classified into 18 groups by cross hybridization and partial sequencing. Northern blot analysis revealed that the transcripts corresponding to the respective cDNA groups began accumulating at the early stages of meiosis and exhibited clone-specific profiles during meiosis and the spore formation process. The amino acid sequences of the predicted gene products showed similarity with known gene products, e.g. heat shock proteins, serine proteases in Bacillus, and RAD 51 gene product in yeast. Half of the putative gene products had hydrophobic N-terminal regions, suggesting that they may function as signal peptides.