Timeless Changes

Abstract

Diapause, a developmental suspension in insects often occurring in the winter, is induced by temperature and light conditions, which for the fruit fly Drosophila vary significantly over its European range (see the Perspective by Bradshaw and Holzapfel). In Drosophila , the circadian rhythm gene timeless affects diapause, and Tauber et al . identify an allelic variant of timeless that can generate only one of the two known alternative forms of this protein. The coding variant, which affects the time when insects enter diapause, is found at higher frequencies at its putative origin and decreases in frequency in all directions along a latitudinal cline throughout Europe, which suggests the influence of environmental selection. Sandrelli et al . show that this variant results in more stable protein-protein interactions between timeless protein and its partners, which may explain the selective difference in the timing of diapause among individuals of different genotypes. E. Tauber, M. Zordan, F. Sandrelli, M. Pegoraro, N. Osterwalder, C. Breda, A. Daga, A. Selmin, K. Monger, C. Benna, E. Rosato, C. P. Kyriacou, R. Costa, Natural selection favors a newly derived timeless allele in Drosophila melanogaster . Science 316 , 1895-1898 (2007). [Abstract] [Full Text] F. Sandrelli, E. Tauber, M. Pegoraro, G. Mazzotta, P. Cisotto, J. Landskron, R. Stanewsky, A. Piccin, E. Rosato, M. Zordan, R. Costa, C. P. Kyriacou, A molecular basis for natural selection at the timeless locus in Drosophila melanogaster . Science 316 , 1898-1900 (2007). [Abstract] [Full Text] W. Bradshaw, C. Holzapfel, Tantalizing timeless . Science 316 , 1851-1852 (2007). [Summary] [Full Text]