Association between the Effects of High Temperature on Fertility and Sleep in Female Intra-Specific Hybrids of Drosophila melanogaster

SIMPLE SUMMARY: Given the complexity of the human reproduction system and the numerous limitations imposed on human studies, a fruit fly model was used to investigate whether the effects of high temperature on fertility and sleep correlate one with another. No evidence was provided for a causal link of temperature-sensitive sterility with sleep disturbance under high temperature in infertile females born from females of Canton-S strain and males of Harwich strain. However, sensitivity of sleep of these females to high temperature differed from that in fertile females born from females of Harwich strain and males of Canton-S strain and in males of either cross. ABSTRACT: Humans and fruit flies demonstrate similarity in sleep-wake behavior, e.g., in the pattern of sleep disturbances caused by an exposure to high temperature. Although research has provided evidence for a clear connection between sleeping problems and infertility in women, very little is known regarding the mechanisms underlying this connection. Studies of dysgenic crosses of fruit flies revealed that an exposure to elevated temperature induces sterility in female intra-specific hybrids exclusively in one of two cross directions (progeny of Canton-S females crossed with Harwich males). Given the complexity and limitations of human studies, this fruit flies’ model of temperature-sensitive sterility might be used for testing whether the effects of high temperature on fertility and on 24-h sleep pattern are inter-related. To document this pattern, 315 hybrids were kept for at least five days in constant darkness at 20 °C and 29 °C. No evidence was found for a causal link between sterility and sleep disturbance. However, a diminished thermal responsiveness of sleep was shown by females with temperature-induced sterility, while significant responses to high temperature were still observed in fertile females obtained by crossing in the opposite direction (i.e., Canton-S males with Harwich females) and in fertile males from either cross.