AUTHOR=Seong Keon Mook , Coates Brad S. , Pittendrigh Barry R. 

TITLE=Impacts of Sub-lethal DDT Exposures on microRNA and Putative Target Transcript Expression in DDT Resistant and Susceptible Drosophila melanogaster Strains

JOURNAL=Frontiers in Genetics

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2019.00045

DOI=10.3389/fgene.2019.00045

ISSN=1664-8021

ABSTRACT=<p>Ten constitutively differentially expressed miRNAs were previously described between DDT-resistant <italic>91-R</italic> and -susceptible control <italic>Drosophila melanogaster</italic> strains, and among their predicted target genes were those associated with metabolic DDT resistance mechanisms. The present study evaluated the inducibility of miRNA expression and putative downstream regulation of cytochrome P450s in response to DDT exposure in a time-dependent manner in <italic>91-R</italic> and the susceptible <italic>Canton-S</italic> strain. Specifically, RT-qPCR analysis showed that DDT exposures led to the significant down-regulation (repression) of <italic>miR-310-3p</italic>, <italic>miR-311-3p</italic>, <italic>miR-312-3p</italic>, <italic>miR-313-3p</italic>, and <italic>miR-92a-3p</italic> levels in <italic>Canton-S</italic>. This is contrasted with the lack of significant changes in <italic>91-R</italic> at most time-points following DDT exposure. The levels of expression among miRNAs exhibited opposite expression patterns compared to their corresponding putative target cytochrome P450s at the same time points after DDT exposure. Collectively, results from this study suggest that <italic>miR-310-3p</italic>, <italic>miR-311-3p</italic>, <italic>miR-312-3p</italic>, <italic>miR-313-3p</italic>, and <italic>miR-92a-3p</italic> might have a potential role in the control of DDT detoxification through the post-transcriptional regulation of target cytochrome P450s in <italic>Canton-S</italic>. Conversely, the lack of significant changes of these same miRNAs in <italic>91-R</italic> following DDT-exposure suggests a possible adaptive mutation that removes repressive control mechanisms. These data are important for the understanding impact of adaptive changes in miRNA expression on post-transcriptional regulatory mechanism involved in the evolution of DDT resistance in <italic>91-R</italic>.</p>