RESUMEN
As the fat body is a critical tissue for mosquito development, metamorphosis, immune and reproductive system function, the characterization of regulatory modules targeting gene expression to the female mosquito fat body at distinct life stages is much needed for multiple, varied strategies for controlling vector-borne diseases such as dengue and malaria. The hexameric storage protein, Hexamerin-1.2, of the mosquito Aedes atropalpus is female-specific and uniquely expressed in the fat body of fourth instar larvae and young adults. We have identified in the Hex-1.2 gene, a short regulatory module that directs female-, tissue-, and stage-specific lacZ reporter gene expression using a heterologous promoter in transgenic lines of the dengue vector Aedes aegypti. Male transgenic larvae and pupae of one line expressed no Escherichia coli ß-galactosidase or transgene product; in two other lines reporter gene activity was highly female-biased. All transgenic lines expressed the reporter only in the fat body; however, lacZ mRNA levels were no different in males and females at any stage examined, suggesting that the gene regulatory module drives female-specific expression by post-transcriptional regulation in the heterologous mosquito. This regulatory element from the Hex-1.2 gene thus provides a new molecular tool for transgenic mosquito control as well as functional genetic analysis in aedine mosquitoes.
Asunto(s)
Aedes/genética , Animales Modificados Genéticamente/genética , Cuerpo Adiposo/fisiología , Proteínas de Insectos/genética , Larva/genética , Región de Flanqueo 5' , Animales , Elementos de Facilitación Genéticos/genética , Escherichia coli , Femenino , Regulación de la Expresión Génica , Masculino , Regiones Promotoras Genéticas , Secuencias Reguladoras de Ácidos Nucleicos , beta-Galactosidasa/genéticaRESUMEN
A portion of the 5'-flanking region of the female-specific hexamerin gene, Hex-1.2, from the mosquito Ochlerotatus atropalpus was used to drive expression of the luciferase reporter gene in Drosophila melanogaster. The proximal 0.7 kb of 5'-flanking DNA were sufficient to partially repress reporter gene activity in males and to drive tissue- and stage-specific expression comparable with that of the endogenous O. atropalpus Hex-1.2 gene. The Drosophila doublesex transcription factor (DSX), expressed in Escherichia coli, bound putative DSX sites of the Hex-1.2 gene differentially in vitro. Blocking expression of the female isoform of the Doublesex transcription factor in transgenic female flies resulted in reduction of luciferase expression to levels comparable with those in males, suggesting that Doublesex could contribute to regulation of female-specific expression of the O. atropalpus Hex-1.2 gene.
Asunto(s)
Regulación de la Expresión Génica , Ochlerotatus/genética , Regiones Promotoras Genéticas , Región de Flanqueo 5' , Animales , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/crecimiento & desarrollo , Electroforesis en Gel de Poliacrilamida , Ensayo de Cambio de Movilidad Electroforética , Cuerpo Adiposo/metabolismo , Femenino , Expresión Génica , Genes Reporteros , Estadios del Ciclo de Vida , Luciferasas/genética , Masculino , Mutación , Proteínas Nucleares/genética , Ochlerotatus/crecimiento & desarrollo , Caracteres SexualesRESUMEN
The stereocontrolled reduction of 3-aryl-5-acetylisoxazolines (1) to the corresponding alcohols (2 and 3) in the presence of four different yeast strains, recognized as Baker's yeast (commercial), Candida krusei (ATCC 14243), Pichia farinosa (NRRL Y110) and Sacchromyces sp. (soil isolate) have been attempted. The C. krusei was found to be diastereoselective for the (R)-1 while the Sacchromyces sp. led to complete reduction to yield the RS- and SS-alcohol in 1:1 ratio at 10 g/L scale.
