Genome-wide association in Drosophila identifies a role for Piezo and Proc-R in sleep latency.

Sleep latency, the amount of time that it takes an individual to fall asleep, is a key indicator of sleep need. Sleep latency varies considerably both among and within species and is heritable, but lacks a comprehensive description of its underlying genetic network. Here we conduct a genome-wide association study of sleep latency.

Nonlinear expression patterns and multiple shifts in gene network interactions underlie robust phenotypic change in Drosophila melanogaster selected for night sleep duration.

All but the simplest phenotypes are believed to result from interactions between two or more genes forming complex networks of gene regulation. Sleep is a complex trait known to depend on the system of feedback loops of the circadian clock, and on many other genes; however, the main components regulating the phenotype and how they interact remain an unsolved puzzle. Genomic and transcriptomic data may well provide part of the answer, but a full account requires a suitable quantitative framework.

Natural selection on sleep duration in Drosophila melanogaster.

Sleep is ubiquitous across animal species, but why it persists is not well understood. Here we observe natural selection act on Drosophila sleep by relaxing bi-directional artificial selection for extreme sleep duration for 62 generations. When artificial selection was suspended, sleep increased in populations previously selected for short sleep.

Short-Term Memory Deficits in the SLEEP Inbred Panel.

Although sleep is heritable and conserved across species, sleep duration varies from individual to individual. A shared genetic architecture between sleep duration and other evolutionarily important traits could explain this variability. Learning and memory are critical traits sharing a genetic architecture with sleep.

The Sleep Inbred Panel, a Collection of Inbred with Extreme Long and Short Sleep Duration.

Understanding how genomic variation causes differences in observable phenotypes remains a major challenge in biology. It is difficult to trace the sequence of events originating from genomic variants to changes in transcriptional responses or protein modifications. Ideally, one would conduct experiments with individuals that are at either extreme of the trait of interest, but such resources are often not available.

Selection for long and short sleep duration in Drosophila melanogaster reveals the complex genetic network underlying natural variation in sleep.

Why do some individuals need more sleep than others? Forward mutagenesis screens in flies using engineered mutations have established a clear genetic component to sleep duration, revealing mutants that convey very long or short sleep. Whether such extreme long or short sleep could exist in natural populations was unknown. We applied artificial selection for high and low night sleep duration to an outbred population of Drosophila melanogaster for 13 generations.

Genotype Influences Day-to-Day Variability in Sleep in Drosophila melanogaster.

Patterns of sleep often vary among individuals. But sleep and activity may also vary within an individual, fluctuating in pattern across time. One possibility is that these daily fluctuations in sleep are caused by the underlying genotype of the individual.

The Genetic Architecture of Ovariole Number in : Genes with Major, Quantitative, and Pleiotropic Effects.

Ovariole number has a direct role in the number of eggs produced by an insect, suggesting that it is a key morphological fitness trait. Many studies have documented the variability of ovariole number and its relationship to other fitness and life-history traits in natural populations of However, the genes contributing to this variability are largely unknown. Here, we conducted a genome-wide association study of ovariole number in a natural population of flies.

Comparison of normalization and differential expression analyses using RNA-Seq data from 726 individual Drosophila melanogaster.

Background: A generally accepted approach to the analysis of RNA-Seq read count data does not yet exist. We sequenced the mRNA of 726 individuals from the Drosophila Genetic Reference Panel in order to quantify differences in gene expression among single flies. One of our experimental goals was to identify the optimal analysis approach for the detection of differential gene expression among the factors we varied in the experiment: genotype, environment, sex, and their interactions.

The genetic basis for variation in olfactory behavior in Drosophila melanogaster.

The genetic underpinnings that contribute to variation in olfactory perception are not fully understood. To explore the genetic basis of variation in olfactory perception, we measured behavioral responses to 14 chemically diverse naturally occurring odorants in 260400 flies from 186 lines of the Drosophila melanogaster Genetic Reference Panel, a population of inbred wild-derived lines with sequenced genomes. We observed variation in olfactory behavior for all odorants.

Natural variation, functional pleiotropy and transcriptional contexts of odorant binding protein genes in Drosophila melanogaster.

How functional diversification affects the organization of the transcriptome is a central question in systems genetics. To explore this issue, we sequenced all six Odorant binding protein (Obp) genes located on the X chromosome, four of which occur as a cluster, in 219 inbred wild-derived lines of Drosophila melanogaster and tested for associations between genetic and phenotypic variation at the organismal and transcriptional level. We observed polymorphisms in Obp8a, Obp19a, Obp19b, and Obp19c associated with variation in olfactory responses and polymorphisms in Obp19d associated with variation in life span.