Functional characterization of the promoter of the vitellogenin gene, AsVg1, of the malaria vector, Anopheles stephensi.
Some genetic strategies for controlling transmission of mosquito-borne diseases call for the introgression of antipathogen effector genes into vector populations. Endogenous mosquito promoter and other cis-acting DNA sequences are needed to direct the expression of the effector molecules to maximize their efficacy. Vitellogenin (Vg)-encoding gene control sequences are candidates for driving tissue-, stage- and sex-specific expression of exogenous genes. One of the Anopheles stephensi Vg genes, AsVg1, was cloned and a full-length cDNA, as well as 850 base pairs adjacent to the 5'-end, were sequenced and characterized. Expression of AsVg1 is restricted to the fat body tissues of blood-fed females, and the amino acid sequence of the conceptual translation product is >85% identical to those of other anopheline Vgs. These characteristics support the conclusion that AsVg1 is a Vg-encoding gene. Functional analyses of the AsVg1 putative cis-regulatory sequences were performed using transgenic mosquitoes. The results showed that DNA fragments encompassing the 850 base pairs immediately adjacent to the 5'-end of the gene and the 3'-end untranslated region are sufficient to direct sex-, stage- and tissue-specific expression of a reporter gene. These data indicate that the AsVg1 promoter is a good candidate for controlling the expression of anti-pathogen effector molecules in this malaria vector mosquito.
Nirmala
Xavier
X
Department of Molecular Biology and Biochemistry, 3205 McGaugh Hall, University of California, Irvine, CA 92697 3900, USA.
Marinotti
Osvaldo
O
Sandoval
Juan Miguel
JM
Phin
Sophea
S
Gakhar
Surendra
S
Jasinskiene
Nijole
N
James
Anthony A
AA
D000818:Animals; D000852:Anopheles / Q000235:genetics*; D001483:Base Sequence; D018076:DNA, Complementary / Q000032:analysis; D005260:Female; D005786:Gene Expression Regulation; D007303:Insect Vectors / Q000235:genetics; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000502:physiology*; D014819:Vitellogenins / Q000235:genetics*
D018076:DNA, Complementary; D014819:Vitellogenins