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.

Age-related differences in biomedical and folk beliefs as causes for diabetes and heart disease among Mexican origin adults.

An understanding of health beliefs is key to creating culturally appropriate health services for Hispanic populations in the US. In this study we explore age-based variations in causal beliefs for heart disease and diabetes among Mexican origin adults in Houston, TX. This cross-sectional study included 497 adults of Mexican origin. Participants were asked to indicate the importance of biomedically defined and folk illness-related risk factors as causes for heart disease and diabetes. Biomedical risk factors were ranked highest as causes of diabetes and heart disease among all participants. Folk illness-related factors were ranked below biomedical factors as causes of heart disease among all age groups. Susto was ranked above the median as a risk factor for diabetes among older participants. Age-related differences in causal beliefs may have implications for designing culturally appropriate health services, such as tailored diabetes interventions for older Mexican origin adults.