Cloning and sequence analysis of mosquito defensin genes.

OBJECTIVE: To clone the defensin genes from the Chinese main mosquito vectors and conduct sequnce analysis. METHODS: The genomic DNA and total RNA were extracted from Aedes aegypti, Aedes albopictus, Culex fatigans and Anopheles sinensis respectively, followed by PCR and reverse transcriptase-PCR with 2 pairs of primers designed and synthesized on the basis of reported defensin gene sequence. Purification and sequence analysis of the PCR products derived from the above procedure were conducted. RESULTS: The products with predicted size were amplified from the genomic DNA of A.aegypti, A.albopictus and A.sinensis. Sequence analysis showed that the amplified fragments from A.aegypti and A.albopictus, but not that from A.sinensis, were highly homologous with the reported defensin sequence. CONCLUSION: The defensin gene of A.aegypti and A.albopictus have been successfully cloned, and the homology of defensin genes among different mosquitoes is parallel to their genetic distances.