Homozygous, yarΔ1A-2/yarΔHR2 and yarΔ1A-2/Df(1)y-ac females show a significant decrease in the level of total nighttime sleep. The average length of each nighttime sleep bout is reduced compared to controls, and coincides with an increase in the number of sleep episodes.
yarΔ1A-2/Df(1)y-ac females do not increase total daytime sleep or the duration of daytime sleep bouts following sleep deprivation (in contrast to control flies). Homozygous and yarΔ1A-2/yarΔHR2 females do increase total daytime sleep and the duration of daytime sleep bouts following sleep deprivation.
y transcription is not altered in this mutant allele, but the level of yar transcription is reduced compared to wild type.