Christine Tabuloc's Exit Seminar: Environmental and anthropogenic impact on insect gene expression and physiology
From Anthony Garcia
"Natural environmental factors and anthropogenic disturbances can modulate gene expression, resulting in alteration of organismal phenotype. In the first part of my thesis project, I used Drosophila melanogaster as an insect model to understand the mechanisms by which 24-hour light-dark cycles can regulate rhythmic changes in the chromatin to generate circadian rhythms of gene expression and orchestrate daily biological rhythms. I observed that two clock proteins, CLOCK and TIMELESS, regulate daily rhythmicity in the binding of BRAHMA, a chromatin remodeler, to DNA spanning clock-controlled genes to facilitate their rhythmic gene expression cycles. Moreover, because TIMELESS degrades in the presence of light, my results provide new insights into how light affects DNA structure and gene expression. In the second part of my thesis project, I investigated the impact of insecticide applications on the fruit pest Drosophila suzukii. Specifically, I performed RNA sequencing analysis on D. suzukii flies that are either susceptible or resistant to common insecticides to determine genetic mechanisms underlying insecticide resistance in this agricultural pest. My results revealed that enhanced metabolic detoxification confers pyrethroid resistance while spinosad resistance is the result of both metabolic and penetration resistance. Finally, we identified alternative splicing as an additional mechanism of resistance. These results will facilitate the development of efficient molecular diagnostics to identify insecticide resistance in the field and enable growers to adjust D. suzukii spray programs to control this devastating pest more effectively."