Sustained positive consequences of genetic rescue of fitness and behavioural traits in inbred populations of Drosophila melanogaster

One solution to alleviate the detrimental genetic effects associated with reductions in population size and fragmentation is to introduce immigrants from other populations. While the effects of this genetic rescue on fitness traits are fairly well known, it is less clear to what extent inbreeding depression and subsequent genetic rescue affects behavioural traits. In this study, replicated crosses between inbred lines of Drosophila melanogaster were performed in order to investigate the effects of inbreeding and genetic rescue on egg-to-adult viability and negative geotaxis behaviour - a locomotor response used to measure e.g. the effects of physiological ageing. Transgenerational effects of outcrossing were investigated by examining the fitness consequences in both the F1 and F4 generation. The majority of inbred lines showed evidence for inbreeding depression for both egg-to-adult viability and behavioural performance (95% and 66% of lines, respectively), with inbreeding depression be..., ,

针对种群规模缩减与生境片段化所引发的有害遗传效应，一种缓解方案是引入其他种群的迁入个体。尽管该遗传拯救（genetic rescue）对适合度性状（fitness traits）的影响已较为明晰，但近交衰退（inbreeding depression）及其后续遗传拯救在多大程度上会影响行为性状（behavioural traits），目前仍不甚明确。本研究以黑腹果蝇（Drosophila melanogaster）的近交系为材料开展重复杂交实验，旨在探究近交与遗传拯救对卵至成虫存活率（egg-to-adult viability）以及负趋地性（negative geotaxis）行为的影响——负趋地性是一种可用于衡量生理衰老等效应的运动反应。本研究通过检测子一代（F1）与子四代（F4）的适合度后果，探究了异交（outcrossing）的跨代效应。多数近交系在卵至成虫存活率与行为表现上均表现出近交衰退迹象（分别占品系总数的95%与66%），而近交衰退……