Project description:Proteomic analysis of Anopheles gambiae brain tissue after in-gel trypsin digestion. To gain insights into neurobiology of the Anopheles gambiae mosquito, we carried out a proteomic analysis of its brain using a comprehensive proteomic approach.
Project description:Malaria-transmitting mosquitoes are extremely sexually dimorphic in their anatomy and behaviour. Sex-specific gene expression in Anopheles gambiae is well-studied in adult stages, but its onset during embryogenesis, apart from sex-determination factors like Yob, remains largely unknown. Here, we report a comprehensive single-embryo transcriptome atlas of A. gambiae males and females to understand the earliest stages of establishing the sex-specific expression networks. Our dataset reveals embryonic RNA isoform diversity including a global shift towards distal alternative polyadenylation (APA) events sites during the maternal-to-zygotic genome transition. Sex-biased gene expression and alternative splicing are limited during embryogenesis, with most sex-specific patterns emerging post-embryonically. X chromosome dosage compensation is established shortly after zygotic genome activation concomitant with direct binding of the master regulator protein SOA to X-linked promoters. In contrast to DC regulators in Drosophila and mammals, we find rather weak evidence in Anopheles for early binding sites or distance-dependent patterns. Instead, both compensation and binding tend to occur locally and uniformly across genes and developmental stages. The most highly expressed genes tend to show the strongest SOA binding. We propose that the Anopheles dosage compensation system represents an extreme case of a gene-by-gene regulatory mechanism that operates at the chromosome-wide level.
Project description:Malaria-transmitting mosquitoes are extremely sexually dimorphic in their anatomy and behaviour. Sex-specific gene expression in Anopheles gambiae is well-studied in adult stages, but its onset during embryogenesis, apart from sex-determination factors like Yob, remains largely unknown. Here, we report a comprehensive single-embryo transcriptome atlas of A. gambiae males and females to understand the earliest stages of establishing the sex-specific expression networks. Our dataset reveals embryonic RNA isoform diversity including a global shift towards distal alternative polyadenylation (APA) events sites during the maternal-to-zygotic genome transition. Sex-biased gene expression and alternative splicing are limited during embryogenesis, with most sex-specific patterns emerging post-embryonically. X chromosome dosage compensation is established shortly after zygotic genome activation concomitant with direct binding of the master regulator protein SOA to X-linked promoters. In contrast to DC regulators in Drosophila and mammals, we find rather weak evidence in Anopheles for early binding sites or distance-dependent patterns. Instead, both compensation and binding tend to occur locally and uniformly across genes and developmental stages. The most highly expressed genes tend to show the strongest SOA binding. We propose that the Anopheles dosage compensation system represents an extreme case of a gene-by-gene regulatory mechanism that operates at the chromosome-wide level.
Project description:The age of mosquitoes is a crucial determinant of their susceptibility to infection, probability of survival to transmit pathogens and tolerance to insecticides. We investigated changes to the abundance of proteins found in heads and thoraces of Anopheles gambiae and Anopheles stephensi as they aged. Protein expression changes were assessed using two-dimensional difference gel electrophoresis and the identity of differentially expressed proteins was determined by using either matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry or capillary high-pressure liquid chromatography coupled with a linear ion-trap (LTQ)-Orbitrap XL hybrid mass spectrometer. Protein biomarkers were validated by quantitative Western blot analysis.
Project description:With their genome sequenced, Anopheles gambiae mosquitoes now serve as a powerful tool for basic research in comparative, evolutionary and developmental biology. The knowledge generated by these studies is expected to reveal molecular targets for novel vector control and pathogen transmission blocking strategies. Comparisons of gene-expression profiles between adult male and nonblood-fed female Anopheles gambiae mosquitoes revealed that roughly 22% of the genes showed sex-dependent regulation. Blood-fed females switch the majority of their metabolism to blood digestion and egg formation within 3 h after the meal is ingested, in detriment to other activities such as flight and response to environment stimuli. Changes in gene expression are most evident during the first, second and third days after a blood meal, when as many as 50% of all genes showed significant variation in transcript accumulation. After laying the first cluster of eggs (between 72 and 96 h after the blood meal), mosquitoes return to a nongonotrophic stage, similar but not identical to that of 3-dayold nonblood-fed females. Ageing and/or the nutritional state of mosquitoes at 15 days after a blood meal is reflected by the down-regulation of 5% of all genes. A full description of the large number of genes regulated at each analysed time point and each biochemical pathway or biological processes in which they are involved is not possible within the scope of this contribution. Therefore, we present descriptions of groups of genes displaying major differences in transcript accumulation during the adult mosquito life. However, a publicly available searchable database (Anopheles gambiae Gene Expression Database at UC Irvine) has been made available so that detailed analyses of specific groups of genes based on their descriptions, functions or levels of gene expression variation can be performed by interested investigators according to their needs. Keywords: response to bloodmeal
Project description:In order to examine the gene expression in the course of mosquito embryogenesis, microarray assays were performed on staged A. gambiae embryos, from fertilization to 52 hours of development (which is close to hatching at ~50 hours post-fertilization). RNA was extracted from staged embryos roughly every three hours after fertilization, and then hybridized to the A. gambiae transcriptome microarray. Keywords: time-course