Abstract:

Cytochrome P450 subfamily 6 genes are specific for insects and associated with resistance. The cyp6u1 gene of the silkworm, Bombyx mori, was cloned to test whether the cyp6u1 is related with the fluorine resistance. The sequence homologous with Drosophila melanogaster cyp6u1 gene was obtained using bioinformatics method, from which it was predicted that the open reading frame (ORF) is 1 476 bp in length, encoding 491 amino acids. The molecular weight of the deduced protein is 56.15 kD and the isoelectric point is 9.23. Using the testis cDNA of day-3 5th instar larvae of the silkworm as the template to amplify with PCR primers designed, we obtained a band of 1 500 bp.  The ORF is close to the predicated value of the silkworm cyp6u1, which was named Bmcyp6u1 (GenBank accession number: HM130560). Homologous analysis showed that it is closely related to cyp6AS13 from Apis mellifera (56%), cyp72A82 from Arabidopsis thaliana (48%) and cyp3A7 from Homo sapiens (50%). Microarray data analysis showed that Bmcyp6u1 gene from day-3 5th instar larvae of the silkworm had very low expression level in all tissues, and was only slightly expressed in testis tissue. These results suggest that the gene has tissue specificity.

Key words: Bombyx mori, Bmcyp6u1, molecular cloning, sequence analysis, expression pattern