Molecular cloning of rice cDNAs related to pollen development using the subtraction hybridization technique

The meiotic stage of pollen mother cell is a very important stage in contro lling the development and formation of pollen. In order to clone the rice c DNA(s) of this stage, a normal rice, Annong N and its thermosensitive mutan t, Annong S-1 were used as the plant material. The mRNA has been extracted from the young panicle at the meiotic stage. By using the cDNA subtraction hybridization technique, three cDNA fragments, RP-1, RP-2 and RP-3 have bee n successfully cloned from Annong N. Northern blot analysis reveals that th e mRNA of these three clones are expressed only in anthers, and not leaves. The mRNA levels of these clones are lower in anthers of Annong S-1 than in Annong N. Furthermore, the amount of mRNA extracted from anthers of Annong S-1 growing under high temperature (28 degrees C) is lower than plants gro wing at lower temperature (25 degrees C). Sequence analysis and homology se arch indicate that these three clones display no similarity to the current database. It is concluded that the three novel cDNA cloned are related to p ollen development in rice.