Project description:The emergence of insecticide resistance is a fast-paced example of the evolutionary process of natural selection. In our study, we investigated the molecular basis of resistance in the myiasis-causing fly Cochliomyia hominivorax (Diptera: Calliphoridae) to organophosphates (OP). By sequencing the RNA from surviving larvae treated with OP (resistant condition) and non-treated larvae (control condition), we identified genes displaying condition-specific polymorphisms, as well as those differentially expressed. Both analyses revealed that resistant individuals have altered expression and allele-specific expression of genes involved in proteolysis (specifically serine-endopeptidase), olfactory perception and cuticle metabolism, among others. We also confirmed that resistant individuals carry almost invariably the Trp251Ser mutation in the esterase E3 known to confer OP and Pyrethroid resistance. Interestingly, genes involved in metabolic and detoxifying processes (notably cytochrome P450s) were found under-expressed in resistant individuals. An exception to this were esterases, which were found up-regulated. These observations suggest that reduced penetration and aversion to OP contaminated food, may be important complementary strategies of resistant individuals. The specific genes and processes found are an important starting point for future functional studies. Their role in insecticide resistance merits consideration to better the current pest management strategies.
Project description:Understanding and quantifying the effects of environmental factors influencing the variation of abundance and diversity of microbial communities was a key theme of ecology. For microbial communities, there were two factors proposed in explaining the variation in current theory, which were contemporary environmental heterogeneity and historical events. Here, we report a study to profile soil microbial structure, which infers functional roles of microbial communities, along the latitudinal gradient from the north to the south in China mainland, aiming to explore potential microbial responses to external condition, especially for global climate changes via a strategy of space-for-time substitution. Using a microarray-based metagenomics tool named GeoChip 5.0, we showed that microbial communities were distinct for most but not all of the sites. Using substantial statistical analyses, exploring the dominant factor in influencing the soil microbial communities along the latitudinal gradient. Substantial variations were apparent in nutrient cycling genes, but they were in line with the functional roles of these genes. 300 samples were collected from 30 sites along the latitudinal gradient, with 10 replicates in every site
