D3163: Chronic sleep disturbance extends pregnancy duration in the Pacific beetle-mimic cockroach, Diploptera punctata

The Pacific beetle-mimic cockroach, Diploptera punctata, is viviparous, undergoing hormonal cycles during pregnancy that influence many biological aspects. In other live-bearing species, daily rhythms and circadian cycles, including sleep, are impacted by pregnancy. Here, we examined daily rhythms, sleep, and risk-taking behavior between the sexes in relation to the pregnancy cockroach status. The peak of activity occurs directly following nightfall, but there is no difference between pregnant and non-pregnant females in activity (males are significantly more active). Cockroaches predominantly sleep during the day, with females sleeping more than males. Emergence during the day to night transition was similar for pregnant and nonpregnant females, suggesting no change in scavenging or risk-taking behavior during pregnancy. Although sleep duration and activity levels do not appear to be influenced by pregnancy, sleep is critical to embryo development. Chronic disturbance of pregnant females during the day, but not the night, resulted in an extension of pregnancy, suggesting that sleep deprivation during the day will impact pregnancy. Supporting that daytime sleep is critical to pregnancy, the expression of transcripts for milk proteins was reduced in D. punctata following chronic disturbance during the day, demonstrating a critical role for sleep periods in milk production to feed developing embryos. Investigating the relationship between circadian rhythms and pregnancy factors such as milk production, hormonal cycles related to immune response, gestational duration, and behavior may help to uncover the role of sleep and circadian activity in viviparous insects.