The role of pumilio in hemocytes in the modulation of alcohol induced responses in <em>Drosophila melanogaster</em>.

Abstract

In this dissertation, the fruit fly <em>Drosophila melanogaster</em> was used as a model organism to study the effects of ambient temperature and role of pumilio via macrophages in alcohol induced responses.<br /> <br /> When ethanol assay was performed using Hml-pumRNAi flies and Hml-GFP flies, at various temperature, we found that, Temperature have little effects on the acute response to alcohol compared to the effects on tolerance. This finding indicate that temperature preferentially affects how flies adapt to alcohol rather than the initial direct responses. Alcohol tolerance is higher in the cold than in warmer environments suggesting that the adaptations associated with tolerance may be facilitated by cold temperatures. Knockdown of pumilio in hemocytes reduces tolerance and abolishes its sensitivity to changes in temperature. This finding suggests that pumilio plays a key role in mediating hemocyte-responses to temperature.<br /> <br /> In an attempt to under how these behavioral changes can corelate to the gene expression pattern in fly brains, we performed RNA-sequencing analysis on fly brain after being exposed to ethanol only on day1. Transcriptomics data revealed that, Knockdown of pumilio in hemocytes affects gene expression in the brain. This suggest a novel hemocyte-brain communication in the regulation of ethanol tolerance. The differentially expressed genes (DEG) identified by interaction analysis, revealed that whose expression was significantly altered by alcohol and regulated by pumilio, were all involved in meditating neuroadaptations to environmental stress such as pathogens, starvation and alcohol. This suggest that neuroadaptations to high doses of alcohol are triggered by general stress-response mechanisms and that pumilio may be a key stress mediator linking cellular stress-detecting systems and cellular stress-management systems.<br /> <br /> As we know ambient temperature influences the ethanol induced behaviors-sensitivity and tolerances. Now we want to understand if ethanol doses can also influence the manifestations of ethanol sensitivity and tolerances. When flies were exposed to various ethanol concentrations (50%, 75%, and 100%) at various temperatures (19°C, 25°C, 28°C), we found out that, doses have no effect on ethanol sensitivity across temperature but do develop tolerance across doses and temperature.