This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Lakin-Thomas, P. L. Search for Related Content PubMed PubMed Citation Articles by Lakin-Thomas, P. L. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB CHOLINE BITARTRATE CHOLINE CHLORIDE Social Bookmarking                         What's this?

Choline Depletion, frq Mutations, and Temperature Compensation of the Circadian Rhythm in Neurospora crassa

Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK

In the fungus Neurospora crassa, the chol-1 mutation blocks the synthesis of the lipid phosphatidylcholine and also lengthens the period of the circadian rhythm of conidiation under conditions of choline depletion. The frq mutations, which have no known metabolic defect, affect both the period of the rhythm and temperature compensation. In this article, the chol-1 mutant strain has been further characterized with respect to its temperature compensation and its interactions with frq. Choline depletion of chol-1 abolishes good temperature compensation: Low temperatures lengthen the period under choline-depleted conditions, and low choline lengthens the period at any one temperature. Double-mutant strains carrying both chol-1 and one of a series of frq alleles demonstrate interactions between chol-1 and frq: On high choline, the periods of the double mutants are identical to the corresponding chol+ strains, whereas on low choline all double mutants display very long periods (greater than 50 h). Short-period frq mutations shorten the long period on low choline, whereas long-period frq mutations have no effect. A null frq mutation in the chol-1 background is arrhythmic on high choline but is robustly rhythmic on low choline and has no effect on the long period. The interactions between frq and chol-1 are similar to the interactions between frq and cel, another lipid-deficient mutant. These results provide support for the hypothesis that membrane lipids may be involved in temperature compensation of the circadian rhythm. The possibility is discussed that the frq gene may not be required for circadian rhythmicity under some conditions and therefore may not be a central component of the circadian oscillator but rather a component of an input pathway.

Key Words: circadian • clock • Neurospora • choline • temperature compensation • frequency

Journal of Biological Rhythms, Vol. 13, No. 4, 268-277 (1998)
DOI: 10.1177/074873098129000101


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				K. Schneider, S. Perrino, K. Oelhafen, S. Li, A. Zatsepin, P. Lakin-Thomas, and S. Brody Rhythmic Conidiation in Constant Light in Vivid Mutants of Neurospora crassa Genetics, March 1, 2009; 181(3): 917 - 931. [Abstract] [Full Text] [PDF]

				M. Shi, L. F. Larrondo, J. J. Loros, and J. C. Dunlap A developmental cycle masks output from the circadian oscillator under conditions of choline deficiency in Neurospora PNAS, December 11, 2007; 104(50): 20102 - 20107. [Abstract] [Full Text] [PDF]

				L. Lombardi, K. Schneider, M. Tsukamoto, and S. Brody Circadian Rhythms in Neurospora crassa: Clock Mutant Effects in the Absence of a frq-Based Oscillator Genetics, March 1, 2007; 175(3): 1175 - 1183. [Abstract] [Full Text] [PDF]

				J. J. Loros, J. C. Dunlap, L. F. Larrondo, M. Shi, W. J. Belden, V. D. Gooch, C.-H. Chen, C. L. Baker, A. Mehra, H. V. Colot, et al. Circadian Output, Input, and Intracellular Oscillators: Insights into the Circadian Systems of Single Cells Cold Spring Harb Symp Quant Biol, January 1, 2007; 72(0): 201 - 214. [Abstract] [PDF]

				R. M. de Paula, M. W. Vitalini, R. H. Gomer, and D. Bell-Pedersen Complexity of the Neurospora crassa Circadian Clock System: Multiple Loops and Oscillators Cold Spring Harb Symp Quant Biol, January 1, 2007; 72(0): 345 - 351. [Abstract] [PDF]

				T. Roenneberg, Z. Dragovic, and M. Merrow Demasking biological oscillators: Properties and principles of entrainment exemplified by the Neurospora circadian clock PNAS, May 24, 2005; 102(21): 7742 - 7747. [Abstract] [Full Text] [PDF]

				A. M. Pregueiro, N. Price-Lloyd, D. Bell-Pedersen, C. Heintzen, J. J. Loros, and J. C. Dunlap From The Cover: Assignment of an essential role for the Neurospora frequency gene in circadian entrainment to temperature cycles PNAS, February 8, 2005; 102(6): 2210 - 2215. [Abstract] [Full Text] [PDF]

				P. L. Lakin-Thomas and S. Brody Circadian rhythms in Neurospora crassa: Lipid deficiencies restore robust rhythmicity to null frequency and white-collar mutants PNAS, January 4, 2000; 97(1): 256 - 261. [Abstract] [Full Text] [PDF]

				J.-C. Leloup, D. Gonze, and A. Goldbeter Limit Cycle Models for Circadian Rhythms Based on Transcriptional Regulation in Drosophila and Neurospora J Biol Rhythms, December 1, 1999; 14(6): 433 - 448. [Abstract] [PDF]

				T. Roenneberg and M. Merrow Circadian Systems and Metabolism J Biol Rhythms, December 1, 1999; 14(6): 449 - 459. [Abstract] [PDF]

				M. Ramsdale and P. L. Lakin-Thomas sn-1,2-Diacylglycerol Levels in the Fungus Neurospora crassa Display Circadian Rhythmicity J. Biol. Chem., September 1, 2000; 275(36): 27541 - 27550. [Abstract] [Full Text] [PDF]