生物谷報道:時序和其它生理節(jié)奏內在周期性控制著人體蘇醒與睡眠的循環(huán)生物鐘,,科學家們認為這種生理周期性也許已經進化到了能預見環(huán)境內的調控性短暫變化,,但是有關生理周期性的兩個方面:24小時的日夜周期以及每年季節(jié)變化的周期之間的關系,,目前了解的并不太多。
在本期的Science(6月29日)雜志上,,兩個研究小組獲得了突破性的發(fā)現(xiàn):他們發(fā)現(xiàn)果蠅的一種變異能幫助這種果蠅進入一個名為“滯育”的類似冬眠的生長停止狀態(tài),,這一發(fā)現(xiàn)連接了生理周期性的日夜周期和季節(jié)變化的周期。
在第一篇文章中,,來自英國的萊斯特大學(University of Leicester)遺傳學和生物學系的研究人員發(fā)現(xiàn)黑腹果蠅中有一個生理節(jié)律基因變異:timeless,,攜帶這一變異的果蠅比野生型果蠅能更好地響應環(huán)境的變化。
通過進一步的將timeless基因引入不同的遺傳背景,,研究人員還發(fā)現(xiàn)timeless基因天然的和人工的等位基因都會影響果蠅對外部光度和溫度作出反應。這一變異通過自然選擇傳遍了歐洲,,這種變化改變了一個重要的生活史,,從而也許增加了果蠅對季節(jié)條件變化的適應能力。
英文原文:
Science 29 June 2007:
Vol. 316. no. 5833, pp. 1895 - 1898
DOI: 10.1126/science.1138412
Natural Selection Favors a Newly Derived timeless Allele in Drosophila melanogaster
Eran Tauber,1* Mauro Zordan,2* Federica Sandrelli,2* Mirko Pegoraro,1,2 Nicolò Osterwalder,2 Carlo Breda,1,2 Andrea Daga,2 Alessandro Selmin,1,2 Karen Monger,1 Clara Benna,2 Ezio Rosato,1 Charalambos P. Kyriacou,1 Rodolfo Costa2
Circadian and other natural clock-like endogenous rhythms may have evolved to anticipate regular temporal changes in the environment. We report that a mutation in the circadian clock gene timeless in Drosophila melanogaster has arisen and spread by natural selection relatively recently in Europe. We found that, when introduced into different genetic backgrounds, natural and artificial alleles of the timeless gene affect the incidence of diapause in response to changes in light and temperature. The natural mutant allele alters an important life history trait that may enhance the fly's adaptation to seasonal conditions.
1 Department of Genetics, University of Leicester, Leicester LE1 7RH, UK.
2 Department of Biology, University of Padova, 35131 Padova, Italy.
* These authors contributed equally to this work.
Present address: Department of Pharmacology, University of Padova, Largo Meneghetti 2, 35131 Padova, Italy.
To whom correspondence should be addressed. E-mail: cpk@leicester.ac.uk
在第二篇文章中,,來自意大利帕多瓦大學(University of Padova),,英國萊斯特大學(University of Leicester),,德國雷根斯堡大學(University of Regensburg)的研究人員在上一個研究的基礎上進行了延伸研究,發(fā)現(xiàn)這一變異導致身體時鐘機制中更穩(wěn)定的蛋白質-蛋白質相互作用,。