Chapter 1 The biological clock: it's all in the genes

Abstract

Publisher Summary This chapter focuses on the recent progress using genetic approaches to study circadian rhythms in mammals. A central question in the field of circadian rhythms concerns the molecular mechanism of circadian clocks. Two general approaches have been used to study the cellular and molecular mechanisms regulating circadian rhythms—physiological analysis and genetic analysis using circadian clock mutants. Until recently, most work in the field has favored physiological approaches; however, a new era in which the genetic approach can also be successfully applied to mammals is now growing up. While substantial progress has been achieved in the understanding of the neurobiology and physiology of circadian rhythms, much less is known about the molecular mechanisms that generate circadian rhythms in mammals. N-ethyl-N-nitrosourea (ENU) mutagenesis and screening for clock mutants provides an efficient approach to identify previously unknown genes, using phenotype-driven methods. The isolation of clock is just the beginning of the attempts to open and understand the black box that has so far represented the molecular mechanism of the circadian clock in mammals.