Abstract
Sleep causes changes in gene expression which result in improved cognition and overall better health. Because micro-RNAs (miRs) are important regulators of gene expression, a screen for miRs that are involved in sleep was performed by the Griffith Lab using the fruit fly Drosophila melanogaster. This screen implicated miR-190 as an important regulator of sleep. To verify that miR-190 is required in neurons for its effects on sleep, I used the GAL4/UAS system to express a miR-190 inhibitor in neurons only. Total sleep was significantly decreased, as was mean sleep episode duration. I attempted to further localize the activity of miR-190 by inhibiting the miR in a variety of neuronal subsets and general brain areas. In brain areas such as the fan-shaped bodies, which have been implicated in homeostatic regulation of sleep, lack of miR-190 reduced total sleep and elicited a fragmentation phenotype, suggesting that miR-190 could be partly responsible for regulating sleep consolidation. This phenotype recurred in many brain areas and neuronal populations, suggesting that the need for miR-190 function for consolidated sleep is widespread throughout the brain. Using CRISPR/cas9 genome editing, fly lines with endogenous mutations in the mir-190 gene were created. When their sleep was tested, it was indistinguishable from experiments performed with a miR-190 inhibitor expressed in neurons, increasing the validity of previous results. Overall, miR-190 is important in the Drosophila melanogaster brain for sleep regulation. A better understanding of this function may yield insight into human sleep disorders and other chronic illnesses.