Abstract：To investigate mechanism of fluoride-resistance to highly resistant silkworm, using fluorescent different display technique, a differentially expressed cDNA amplicon A14-6 was identified and denoted Bmbcl-2(AB008449), which encodes antiapoptosis protein. Bioinformatics analyses indicates that Bmbcl-2 encodes 965 amino acid with relative molecular mass being 108.800kD，and that isoelectric point was 6.370. The protein has no hydrophobic transmembrane anchor region at the C-terminus and has 19 exons and 18 introns, and splice sites conform to GT/AG rule. Protein analyses indicated that BCL-2 family proteins contain four evolutionarily conserved regions known as BH1、 BH2、 BH3 and BH4, but low homologues between BmBCL-2 and other BCL-2 family proteins by using ClustalX1.83 and MEGA3.1 software. RT-PCR results showed that the Bmbcl-2 expressed in five tissues of the 48h of 5th instar silkworm，but its expression was higher in midgut and fat body in 441DZ. Highly fluoride-resistant strain 441 and highly susceptible strain 440 were used. After treated with water and 200mg•L-1, the transcription level of Bmbcl-2 was higher in 441F than in 440F, while there was no significant change in water treatment. The results indicated that Bmbcl-2 may be related with fluoride-resistance.
