RESUMO
The DREP-1 gene plays an important role in the process of apoptosis in Drosophila. The amino acid sequence of Drosophila ICAD was searched against the silkworm EST database. The resulted ESTs were clustered and assembled into a consensus sequence. Primers based on the consensus sequence were designed and the full length cDNA of ICAD gene, designated BmICAD, was cloned firstly from Bombyx mori. This BmICAD cDNA was 844-bp in length, containing a 522-bp open reading frame (ORF), which encoded a protein of 174 amino acids; the molecular weight of this protein was estimated to be 19.6 kDa and the isoelectric point was 4.23. The BmICAD protein shares 36% identity with Drosophila DREP-1. No signal has inspected by Northern blot, but RT-PCR analysis showed that BmICAD was testis-specific expressed at the mRNA level. Structure and clustering analysis indicated that this gene might be involved in the process of apoptosis that regulate the degradation of DNA.