Manoli Giulia, Lankinen Pekka, Bertolini Enrico, Helfrich-Förster Charlotte
Neurobiology and Genetics, Biocenter, University of Würzburg, Würzburg, Germany.
Department of Ecology and Genetics, University of Oulu, Oulu, Finland.
Open Biol. 2025 Mar;15(3):240403. doi: 10.1098/rsob.240403. Epub 2025 Mar 5.
Insects can survive harsh conditions, including Arctic winters, by entering a hormonally induced state of dormancy, known as diapause. Diapause is triggered by environmental cues such as shortening of the photoperiod (lengthening of the night). The time of entry into diapause depends on the latitude of the insects' habitat, and this applies even within a species: populations living at higher latitudes enter diapause earlier in the year than populations living at lower latitudes. A long-standing question in biology is whether the internal circadian clock, which governs daily behaviour and serves as a reference clock to measure night length, shows similar latitudinal adaptations. To address this question, we examined the onset of diapause and various behavioural and molecular parameters of the circadian clock in the cosmopolitan fly, , a species distributed throughout Europe from the Black Sea (41° N) to Arctic regions (69° N). We found that all clock parameters examined showed the same correlation with latitude as the critical night length for diapause induction. We conclude that the circadian clock has adapted to the latitude and that this may result in the observed latitudinal differences in the onset of diapause.
昆虫能够通过进入一种由激素诱导的休眠状态（称为滞育）来在包括北极冬季在内的恶劣条件下生存。滞育由环境线索触发，如光周期缩短（夜晚变长）。进入滞育的时间取决于昆虫栖息地的纬度，即使在同一物种内也是如此：生活在高纬度地区的种群比生活在低纬度地区的种群更早进入滞育。生物学中一个长期存在的问题是，控制日常行为并作为测量夜长参考时钟的内部生物钟是否表现出类似的纬度适应性。为了解决这个问题，我们研究了遍布欧洲从黑海（北纬41°）到北极地区（北纬69°）的世界性果蝇物种的滞育开始情况以及生物钟的各种行为和分子参数。我们发现，所检查的所有时钟参数与诱导滞育的临界夜长一样，与纬度呈现相同的相关性。我们得出结论，生物钟已经适应了纬度，这可能导致观察到的滞育开始的纬度差异。
