Year: 2019
Type: conference-abstract
Abstract: One of the hallmarks of insomnia in humans is difficulty initiating sleep. Sleep latency, the amount of time it takes to fall asleep initially, is one way to quantify this difficulty. Sleep latency can be easily measured in flies as the time to the fly’s first night sleep bout. In this study, we leveraged raw sleep and activity data from a previous genome-wide association study (GWAS) of Drosophila melanogaster. Our goal was to assess the extent of genetic variation in sleep latency in a wild-derived population of flies and to identify polymorphic variants explaining that variation. Using the raw data, we calculated the average sleep latency over six days per fly in the Drosophila Genetic Reference Panel (DGRP). We associated 1,920,276 polymorphic variants with sleep latency in a mixed model that accounted for population structure, Wolbachia pipientis infection status, and the presence/absence of large chromosomal inversions. Sleep latencies averaged 41.4 minutes in the DGRP and ranged from 4.1 to 178.0 minutes. Genetic variation for sleep latency was relatively high; broad-sense heritability was H2 = 0.443 for both sexes combined. We observed sex-specific effects for sleep latency; the cross-sex correlation was 0.656, with male sleep latency being somewhat higher on average than that of females. We found 855 polymorphisms significantly associated with sleep latency. Of these polymorphisms, 91 were significant for both sexes combined and were located ± 1000 bp of 67 candidate genes. We are currently confirming the predicted effects on sleep latency for 24 candidate genes using readily available knock-down insertions. Sleep latency is highly variable among wild-type flies and heritable. GWAS results suggest that the genetic architecture of sleep latency is polygenic and maps to genes with roles in central nervous system development and morphogenesis. This work was supported by the Intramural Research Program of the National Institutes of Health, The National Heart Lung and Blood Institute.
Source: SLEEP
Authors: Matthew N Eiman, Susan T Harbison
Institution: National Heart, Lung, and Blood Institute
Language: English
Subfield: Cellular and Molecular Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: bronze
Funder: National Institutes of Health
OpenAlex ID: W2936971787