tailieunhanh - Báo cáo y học: " A weed for all reasons"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: A weed for all reasons. | Meeting report A weed for all reasons Vivian F Irish and Christopher D Day Addresses Departments of Molecular Cellular and Developmental Biology and of Ecology and Evolutionary Biology Yale University New Haven CT 06520-8104 USA. Department of Botany University of Wisconsin-Madison 430 Lincoln Drive Madison WI 53706 USA. Correspondence Vivian F Irish. E-mail Published 28 September2005 Genome Biology 2005 6 350 doi gb-2005-6-l0-350 The electronic version of this article is the complete one and can be found online at http 2005 6 10 350 2005 BioMed Central Ltd A report on the 16th International Arabidopsis Conference Madison USA 15-19 June 2005. This year s meeting on the model plant Arabidopsis highlighted the progress that has been made in many areas of its biology by the use of a variety of genetic and genomic tools. One recurring theme was how multiple layers of transcriptional and posttranscriptional regulation are integrated to produce a biological response. Triggers for flowering Particularly notable was the progress in understanding how flowering time is regulated by extrinsic and intrinsic signals Figure 1 . In some Arabidopsis winter annual cultivars a cold period is required to induce flowering a phenomenon known as vernalization as reviewed by Rick Amasino University of Wisconsin Madison USA . Extended cold leads to a stable epigenetic change that results in histone methylation at the FLOWERING LOCUS C FLC gene which encodes a repressor of flowering. The histone methylation silences FLC expression thus rendering the FLC repressor mechanism inactive and making the plants competent to flower. Modulation of FLC expression is thus key to the process of vernalization. Amasino described a novel allele of FLC that is permanently inactive as a result of the insertion of a heterochromatic island in an intron and showed that maintenance of the heterochromatic state is mediated by short interfering RNAs siRNAs . Another