Abai, MR

6th International Congress of DipterologyThe expression of the cecropin genes in Armigeres subalbatusYang, C. Y. (1), W.T. Liu (1), C.C. Chen (2), W.C. Tu (3) & K.H. Lu (3)(1) Medical Insects Laboratory, Graduate School of Entomology Studies, National ChungHsing University, South District, Taichung City 40227, Taiwan (R.O.C.)(2) Institute of Parasitology, National Yang-Ming University, Beitou District, Taipei City112, Taiwan (R.O.C.)(3) Institute of Entomology, National Chung Hsing University, South District, TaichungCity 40227, Taiwan (R.O.C.)Five cecropin genes, AsCec 1, AsCec 2, AsCec 4, AsCec 6, AsCec 7, wereexpressed in the adult mosquito, Armigeres subalbatus, by inoculatingheat-killed Escherichia coli. Most expressed genes were inducible exceptAsCec 6. However, an interesting phenomenon observed in AsCec 6 wasthe constitutive expression in both adult and larval stages, which was notaffected by the microbial challenge as that of Staphylococcuc aureus,Nomuraea rileyi, and E. coli. A novel gene-expressed profile was alsoobserved in AsCec 6 that the expression of AsCec 6 declined 1 hr afterpupation and then disappeared till 48 hr, but expressed again at 72 hr afterpupation. During the early period of pupae, AsCec 6 was inducible andpersistently expressed until 18 hours with E. coli treatment, then graduallydecreased to lowest at 36 hr, and finally rise again from 48 hr tillemergence. Furthermore, the gene function of AsCec 6 was verified byusing the RNAi technique. Silencing of AsCec 6 resulted in the failure ofemergence or morphological abnormal of adult legs. The results reveal thatAsCec 6 may serve as peptide antibiotics as well as play an important rolein the emergence of Ar. subalbatus.Key Words: cecropin, Armigeres subalbatus∗∗∗∗∗∗∗∗∗∗319