生物谷報(bào)道：日本理化研究所的一個(gè)研究小組近日成功在蒼蠅體內(nèi)發(fā)現(xiàn)生物鐘的遺傳基因，改變這些基因會(huì)導(dǎo)致蒼蠅的生物鐘周期延長(zhǎng)兩小時(shí),。
據(jù)日本《朝日新聞》日前報(bào)道，研究小組對(duì)于影響蒼蠅生活規(guī)律的137個(gè)基因分別進(jìn)行改造,，然后觀察這些改造對(duì)蒼蠅生活規(guī)律的影響,。研究發(fā)現(xiàn)，如果把蒼蠅體內(nèi)一種名為“CWO”的基因關(guān)閉,，使其不再發(fā)揮作用,，那么蒼蠅的生物鐘周期從原先的24小時(shí)變成了26小時(shí)。
研究小組負(fù)責(zé)人上田泰己說(shuō),，“今后還將進(jìn)一步研究‘CWO’基因和其他生物鐘基因的關(guān)系,，這一研究可為揭開人類生物鐘的秘密提供幫助。”
日本研究人員的這一發(fā)現(xiàn)刊登在最新一期美國(guó)《基因與發(fā)育》雜志網(wǎng)站上,。（引自新華網(wǎng)）
原始出處：
Published online before print June 19, 2007
Genes and Development, DOI: 10.1101/gad.1552607
Clockwork Orange is a transcriptional repressor and a new Drosophila circadian pacemaker component
Sebastian Kadener1, Dan Stoleru1,2, Michael McDonald3, Pipat Nawathean1,2, and Michael Rosbash1,2,4
1 Department of Biology, Brandeis University, Waltham, Massachusetts 02454, USA; 2 Howard Hughes Medical Institute and National Center for Behavioral Genomics, Brandeis University, Waltham, Massachusetts 02454, USA; 3 Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
Many organisms use circadian clocks to keep temporal order and anticipate daily environmental changes. In Drosophila, the master clock gene Clock promotes the transcription of several key target genes. Two of these gene products, PER and TIM, repress CLK–CYC-mediated transcription. To recognize additional direct CLK target genes, we designed a genome-wide approach and identified clockwork orange (cwo) as a new core clock component. cwo encodes a transcriptional repressor that synergizes with PER and inhibits CLK-mediated activation. Consistent with this function, the mRNA profiles of CLK direct target genes in cwo mutant flies manifest high trough values and low amplitude oscillations. Because behavioral rhythmicity fails to persist in constant darkness (DD) with little or no effect on average mRNA levels in flies lacking cwo, transcriptional oscillation amplitude appears to be linked to rhythmicity. Moreover, the mutant flies are long period, consistent with the late repression indicated by the RNA profiles. These findings suggest that CWO acts preferentially in the late night to help terminate CLK–CYC-mediated transcription of direct target genes including cwo itself. The presence of mammalian homologs with circadian expression features (Dec1 and Dec2) suggests that a similar feedback mechanism exists in mammalian clocks.
[Keywords: Circadian; clk; Drosophila; transcriptional oscillations; chromatin]
Received March 16, 2007; revised version accepted May 14, 2007.
