Cloning and Alternative Splicing Analysis of Bombyx mori Transformer-2 Gene using Silkworm EST Database

Abstract

We have identified Bombyx mori transformer-2 gene(Bmtra-2)cDNA by blasting the EST database of B.mori.It was expressed in the whole life of the male and female silkworm and was observed as a band of 1.3 kb by Northern blot analysis.By comparing corresponding ESTs to the Bmtra-2 DNA sequence, it was revealed that there were eight exons and seven introns,and all splice sites of exons/introns conformed to the GT/AG rule.Bmtra-2 pre-mRNA can produce multiple mRNAs encoding six distinct isoforms of BmTRA-2 protein using an alternative splicing pathway during processing.Six types of Bmtra-2 cDNA clones were identified by reverse transcription-polymerase chain reaction.All isoforms of BmTRA-2 protein contain two arginine/serine-rich domains and one RNA recognition motif,showing striking organizational similarity to Drosophila TRA-2 proteins.