<span style="font-size:14.0pt;line-height: 115%;font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-IN;mso-fareast-language:EN-IN;mso-bidi-language:HI" lang="EN-IN">Circadian clock genes in <i>Drosophila</i>: Recent developments</span>

Abstract

<span style="font-size:14.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:hi"="" lang="EN-IN">Circadian rhythms provide a temporal framework to living organisms and are established in a majority of eukaryotes and in a few prokaryotes. The molecular mechanisms of circadian clock is constantly being investigated in <i>Drosophila melanogaster</i>. The core of the clock mechanism was described by a transcription-translation feedback loop model involving <i>period (per), timeless (tim),</i> <i>dclock</i> and <i>cycle</i> genes. However, recent research has identified multiple feedback loops controlling rhythm generation and expression. Novel mutations of <i>timeless</i> throw more light on the functions of <i>per </i>and <i>tim</i> products. Analysis of <i>pdf </i>neuropeptide gene (expressed in circadian pacemaker cells in <i>Drosophila)</i>, indicate that PDF acts as the principal circadian transmitter and is involved in output pathways. The product of <i>cryptochrome</i> is known to function as a circadian photoreceptor as well as component of the circadian clock. This review focuses on the recent progress in the field of molecular rhythm research in the fruit fly. The gene(s) and the gene product(s) that are involved in the transmission of environmental information to the clock, as well as the timing signals from the clock outward to cellular functions are remain to be determined.</span>