Abstract
The epigenome of the human malaria vector Anopheles gambiae was characterized in midgut cells by mapping the distribution and levels of two post-translational histone modifications, H3K27ac and H3K27me3. These histone profiles were then correlated with levels of gene expression obtained by RNA-seq. Analysis of the transcriptome of A. gambiae midguts and salivary glands led to the discovery of 13,898 new transcripts not present in the most recent genome assembly. A subset of these transcripts is differentially expressed between midgut and salivary glands. The enrichment profiles of H3K27ac and H3K27me3 are mutually exclusive and associate with high and low levels of transcription, respectively. This distribution agrees with previous findings in Drosophila showing association of these two histone modifications with either active or inactive transcriptional states, including Polycomb-associated domains in silenced genes. This study provides a mosquito epigenomics platform for future comparative studies in other mosquito species, opening future investigations into the role of epigenetic processes in vector-borne systems of medical and economic importance.
Highlights
Host-parasite interactions are among the most plastic and dynamic systems in nature
The expression analysis on the assembly of reads obtained from A. gambiae female mosquito tissues, midguts and salivary glands, resulted in a total of 13,969 novel transcripts that correspond to newly discovered non-annotated loci; combined GTF and BED files available at GEO GSE59773) as well as transcripts categorized as class code “=”correspond in most cases to extensions of previously annotated genes based on intron matches
DIRECTIONS Here we present an integrative approach that combines genomewide profiling of histone modifications and gene expression that allows the functional interpretation of chromatin modifications as well as de novo prediction of regulatory elements and genes
Summary
Host-parasite interactions are among the most plastic and dynamic systems in nature. In these systems, epigenetic modifications can provide an accessory source of fast-acting, reversible and readily available phenotypic variation that can be directly shaped by both host and parasite selection pressures (Bonduriansky and Day, 2009; Gómez-Díaz et al, 2012). Anopheles gambiae is major vector of malaria in Africa, a disease that affects more than 300 million people and causes around 650,000 deaths each year (Who, 2013). Genetic mechanisms alone are not sufficient to explain natural phenotypic variation in terms of vector competence (Lambrechts, 2010). It is critical to expand our current understanding of mosquito-parasite interactions into an integrated view that includes both genetic and epigenetic dimensions. A great deal of progress has been made in deciphering the epigenetic code of Plasmodium parasites (see Hoeijmakers et al, 2012 for a review), knowledge of epigenetic processes in mosquitoes is limited
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
