Cloning and structural and expression analysis of vitellogenin genes of the oriental fruit fly, Bactrocera dorsalis (Hendel)

• Main Authors: Hsiu-Lin Chen, 陳秀玲
• Other Authors: Kuang-Hui Lu
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/21913187421359678661

碩士 === 國立中興大學 === 昆蟲學系 === 89 === In this study, two vitellogenin genes from oriental fruit fly, Bactrocera dorsalis, named Bdvg1 and Bdvg2, respectively, were identified. Bdvg1 was 1507 bp long and contained an open reading frame encoding 437 amino acids. The identities of Bdvg1 were 78.7﹪to CcVG1 of Ceratitis capitata, 76.9﹪to AsYP of Anastrepha suspensa, 67.6﹪to CeYP3 of Calliphora erythrocephala, 65.0﹪to CcVG2 of C. capitata and CeYP2 of C. erythrocephala, respectively. Bdvg2 was 1434 bp long and contained an open reading frame as well encoding 440 amino acids. The identities of Bdvg2 were 71.9﹪to CcVG1 of C. capitata, 70.5﹪to AsYP of A. suspensa, 65.0﹪to CeYP3 of C. erythrocephala, 64.8﹪to CcVG2 of C. capitata and 64.5﹪to CeYP2 of C. erythrocephala. Bdvg1 and Bdvg2 were highly homologous to the other dipteran vitellogenin genes. The carboxyl-end domains of Bdvg1 and Bdvg2 were much conserved in comparison with other fruit flies. However, the amino-end domains were much diversed. The signal sequences of Bdvg1 and Bdvg2 are similar to the signal sequences of vitellogenins of D. melanogaster, C. capitata and C. erythrocephala. 1.5 kb genomic DNA fragment of Bdvg1 was cloned and sequenced. The sequence of this fragment overlapped with the 5’-end of the Bdvg1. The fragment contains an intron that is 67 bp downstream of Bdvg1, and a TATA box and a cap site conserved sequences were found at locatins of —27 to —22 and +3 to +7, respectively. Rt-PCR studies revealed that the vitellogenin genes in B. dorsalis expressed specifically in the adult females but not in males, eggs, larvae and pupae. The Bdvg1 and Bdvg2 expression in ovaries of female adult B. dorsalis significantly increased since day 2 and after. And the Bdvg1 expression in fat body of female adult B. dorsalis significantly increased since day 1 and after but day 2 in Bdvg2. Furthermore, Bdvg1 and Bdvg2 transcripts were detected in the heads, thoraxes and abdomens of 6-day-old adult females.