Role for circadian clock genes in seasonal timing: testing the Bünning hypothesis.
Role for circadian clock genes in seasonal timing: testing the Bünning hypothesis.
复制标题
DOI：
10.1371/journal.pgen.1004603
复制
发表时间：
2014-09
期刊：
影响因子：
4.5
通讯作者：
Tauber E
中科院分区：
文献类型：
--
作者：
Pegoraro M;Gesto JS;Kyriacou CP;Tauber E
A major question in chronobiology focuses around the “Bünning hypothesis” which implicates the circadian clock in photoperiodic (day-length) measurement and is supported in some systems (e.g. plants) but disputed in others. Here, we used the seasonally-regulated thermotolerance of Drosophila melanogaster to test the role of various clock genes in day-length measurement. In Drosophila, freezing temperatures induce reversible chill coma, a narcosis-like state. We have corroborated previous observations that wild-type flies developing under short photoperiods (winter-like) exhibit significantly shorter chill-coma recovery times (CCRt) than flies that were raised under long (summer-like) photoperiods. Here, we show that arrhythmic mutant strains, per01, tim01 and ClkJrk, as well as variants that speed up or slow down the circadian period, disrupt the photoperiodic component of CCRt. Our results support an underlying circadian function mediating seasonal daylength measurement and indicate that clock genes are tightly involved in photo- and thermo-periodic measurements. The circadian clock consists of an extensive genetic network that drives daily rhythms of physiological, biochemical and behavioural processes. The network is evolutionary conserved and has been extensively studied in a broad range of organisms. Another genetic network constitutes the photoperiodic clock and monitors the seasonal change in day-length. Here, we address a major and long-standing question in chronobiology: whether the circadian clock is involved in photoperiodic timing, also known as the Bünning hypothesis. Drosophila, as with many other insects in temperate regions, exhibits a photoperiodic response that allows the insect to anticipate and survive the winter. Here we show that the cold-tolerance of the fly is regulated by the photoperiod. We use this phenotype to test day-length timing in various circadian clock mutants and observe that in null clock mutants, the photoperiodic response is abolished, whereas in mutants that exhibit short or long daily cycles, the photoperiodic response is modified, further supporting a circadian-clock function. Overall, these results provide the first evidence in Drosophila that support for the Bünning hypothesis, and pave the way for the genetic dissection of seasonal timing in Drosophila melanogaster.
登录
查看更多内容
影响因子：
5.4
作者：
Ikeno T;Tanaka SI;Numata H;Goto SG
通讯作者：
Goto SG
DOI：
10.1073/pnas.0308240100
发表时间：
2004-02-17
影响因子：
11.1
作者：
Collins, BH;Rosato, E;Kyriacou, CP
通讯作者：
Kyriacou, CP
影响因子：
3.5
作者：
Menegazzi, Pamela;Vanin, Stefano;Costa, Rodolfo
通讯作者：
Costa, Rodolfo
影响因子：
2.2
作者：
Helfrich-Förster, C
通讯作者：
Helfrich-Förster, C
影响因子：
16.2
作者：
Majercak, J;Sidote, D;Edery, I
通讯作者：
Edery, I