Characterization of three anther-specific genes isolated from Chinese cabbage

Two cDNA libraries were constructed from poly(A)+ RNAs isolated from each of immature flowers (less than 2.0 mm long buds) and anthers (2.0-5.0 mm long buds) of Chinese cabbage (Brassica campestris L. ssp. pekinensis). Using dot-differential hybridization, three cDNA clones, designated BIF38, BAN54, and BAN237, have been isolated from the constructed cDNA libraries and sequenced completely in both directions. Northern blot analyses indicate that all three cDNA clones are abundantly expressed in anther, but not in leaf or other floral organs. The deduced amino acid sequences of BIF38, BAN54, and BAN237 showed high identity with those of known anther-specific genes. Especially the deduced amino acid sequence of BIF38 has 98% identity with that of a phospholipid protein gene (E2) from Brassica napus. Also, the deduced amino acid sequences of BAN54 and BAN237 are similar to the sequences of microspore-specific genes (Bp4A and Bp4C) and pollen oleosins (I3, pol3 and C98), respectively. Southern blot analyses revealed that all three genes belong to multiple gene families in the Chinese cabbage genome.