Project description:The genomes of three major mosquito vectors of human diseases, including Anopheles gambiae, Aedes aegypti, and Culex pipiens quinquefasciatus, have been previously sequenced. C. p. quinquefasciatus has the largest number of predicted protein-coding genes, which partially results from the expansion of three detoxification gene families: cytochrome P450 monooxygenases (P450), glutathione S-transferases (GST), and carboxylcholinesterases (CCE). However, unlike A. gambiae and A. aegypti, which have large amounts of gene expression data, C. p. quinquefasciatus has limited transcriptomic resources. Knowledge of complete gene expression information is very important for the exploration of the functions of genes involved in specific biological processes. In the present study, the three detoxification gene families of C. p. quinquefasciatus were analyzed for phylogenetic classification and compared with those of three other dipteran insects. Gene expression during various developmental stages and the differential expression responsible for parathion resistance were profiled using the digital gene expression (DGE) technique. Results: A total of 291 detoxification genes were found in C. p. quinquefasciatus, including 70 CCE, 186 P450, and 35 GST genes. Compared with three other dipteran species, gene expansion in Culex mainly occurred in the CCE and P450 families, where the genes of M-NM-1-esterases, juvenile hormone esterases, and CYP325 of the CYP4 subfamily showed the most pronounced expansion on the genome. A total of 13314 genes were expressed in five DGE libraries. Genes with signal transduction and odorant binding functions were prominently expressed during egg development. Genes involved in proteolysis, glycosphingolipid biosynthesis, and purine metabolism were preferentially expressed at the larval stage. Seventy five percent of the detoxification genes were found to be expressed. One fourth of the CCE and P450 genes were expressed at unique stages, indicating their developmentally regulated expression. Fifteen detoxification genes, including 2 CCEs, 6 GSTs, and 7 P450s, were expressed at higher levels in a parathion-resistant strain than in a susceptible strain. Conclusion: The results of the present study provide new insights into the functions and evolution of three detoxification gene families in mosquitoes and comprehensive transcriptomic resources for C. p. quinquefasciatus, which will facilitate the elucidation of molecular mechanisms underlying the different biological characteristics of the three major mosquito vectors. Raw data were deposited in SRA and assigned accession number SRA049959: http://www.ncbi.nlm.nih.gov/sra?term=SRA049959 Five DGE libraries were sequenced: the egg, third instar larval, pupal, and adult stages of the SG strain, and the third instar larval stage of the S-lab strain.
Project description:Culex pipiens molestus and Cx. p. quinquefasciatus are the members of Culex pipiens Complex, but they display relatively large differences in behavior and physiological responses. We compared the genes of these mosquitoes to identify those that were differentially expressed in each subspecies. Such genes could play important roles in subspecies-specific blood feeding or oviposition behavior. Culex pipiens molestus and Cx. p. quinquefasciatus females were undertaken Illumina RNA sequencing.
Project description:The Zika outbreak, spread by the Aedes aegypti mosquito, highlights the need to create high-quality assemblies of large genomes in a rapid and cost-effective fashion. Here, we combine Hi-C data with existing draft assemblies to generate chromosome-length scaffolds. We validate this method by assembling a human genome, de novo, from short reads alone (67X coverage, Sample GSM1551550). We then combine our method with draft sequences to create genome assemblies of the mosquito disease vectors Aedes aegypti and Culex quinquefasciatus, each consisting of three scaffolds corresponding to the three chromosomes in each species. These assemblies indicate that virtually all genomic rearrangements among these species occur within, rather than between, chromosome arms. The genome assembly procedure we describe is fast, inexpensive, accurate, and can be applied to many species.
Project description:Lysinibacillus sphaericus produces the mosquito larvicidal binary toxin consisting of BinA and BinB, which are both required for toxicity against Culex and Anopheles larvae. The molecular mechanisms behind Bin toxin-induced damage remain unexplored. We used whole-genome microarray-based transcriptome analysis to better understand how Culex larvae respond to Bin toxin treatment at the molecular level. Our analyses of Culex quinquefasciatus larvae transcriptome changes at 6, 12, and 18 h after Bin toxin treatment revealed a wide range of transcript signatures, including genes linked to the cytoskeleton, metabolism, immunity, and cellular stress, with a greater number of down-regulated genes than up-regulated genes. Bin toxin appears to mainly repress the expression of genes involved in metabolism, the mitochondrial electron transport chain, and the protein transporter of the outer/inner mitochondrial membrane. The induced genes encode proteins linked to mitochondrial-mediated apoptosis and cellular detoxification including autophagic processes and lysosomal compartments.
Project description:The genomes of three major mosquito vectors of human diseases, including Anopheles gambiae, Aedes aegypti, and Culex pipiens quinquefasciatus, have been previously sequenced. C. p. quinquefasciatus has the largest number of predicted protein-coding genes, which partially results from the expansion of three detoxification gene families: cytochrome P450 monooxygenases (P450), glutathione S-transferases (GST), and carboxylcholinesterases (CCE). However, unlike A. gambiae and A. aegypti, which have large amounts of gene expression data, C. p. quinquefasciatus has limited transcriptomic resources. Knowledge of complete gene expression information is very important for the exploration of the functions of genes involved in specific biological processes. In the present study, the three detoxification gene families of C. p. quinquefasciatus were analyzed for phylogenetic classification and compared with those of three other dipteran insects. Gene expression during various developmental stages and the differential expression responsible for parathion resistance were profiled using the digital gene expression (DGE) technique. Results: A total of 291 detoxification genes were found in C. p. quinquefasciatus, including 70 CCE, 186 P450, and 35 GST genes. Compared with three other dipteran species, gene expansion in Culex mainly occurred in the CCE and P450 families, where the genes of α-esterases, juvenile hormone esterases, and CYP325 of the CYP4 subfamily showed the most pronounced expansion on the genome. A total of 13314 genes were expressed in five DGE libraries. Genes with signal transduction and odorant binding functions were prominently expressed during egg development. Genes involved in proteolysis, glycosphingolipid biosynthesis, and purine metabolism were preferentially expressed at the larval stage. Seventy five percent of the detoxification genes were found to be expressed. One fourth of the CCE and P450 genes were expressed at unique stages, indicating their developmentally regulated expression. Fifteen detoxification genes, including 2 CCEs, 6 GSTs, and 7 P450s, were expressed at higher levels in a parathion-resistant strain than in a susceptible strain. Conclusion: The results of the present study provide new insights into the functions and evolution of three detoxification gene families in mosquitoes and comprehensive transcriptomic resources for C. p. quinquefasciatus, which will facilitate the elucidation of molecular mechanisms underlying the different biological characteristics of the three major mosquito vectors. Raw data were deposited in SRA and assigned accession number SRA049959: http://www.ncbi.nlm.nih.gov/sra?term=SRA049959
Project description:The Southern house mosquito, Culex quinquefasciatus, is a vector of the causative agents of many diseases including West Nile Fever, St. Louis Encephalitis, and lymphatic filariasis. In order to manage the spread of these diseases, vector control efforts rely heavily on insecticides, including pyrethroids, namely permethrin. In our study we investigated the changes in the gene expression profiles of a highly-permethrin resistant strain of Cx. quinquefasciatus during constant exposure to permethrin at the LC-0, LC-50, and LC-70 rates, which killed 0, 50, and 70% of all larvae, respectively. Overall, we identified several genes that were up-regulated including detoxification genes such as cytochrome P450s as well as genes that were down-regulated.