THE MEC-3 GENE CONTAINS CIS-ACTING ELEMENTS MEDIATING POSITIVE AND NEGATIVE REGULATION IN CELLS PRODUCED BY ASYMMETRIC CELL-DIVISION IN CAENORHABDITIS-ELEGANS
THE MEC-3 GENE CONTAINS CIS-ACTING ELEMENTS MEDIATING POSITIVE AND NEGATIVE REGULATION IN CELLS PRODUCED BY ASYMMETRIC CELL-DIVISION IN CAENORHABDITIS-ELEGANS
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DOI：
10.1101/gad.5.12a.2199
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发表时间：
1991-12-01
影响因子：
10.5
通讯作者：
WANG, A
中科院分区：
文献类型：
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作者：
WAY, JC;WANG, L;WANG, A
含有homeo box的基因mec-3和unc-86对于指定秀丽隐杆线虫中一组确定的机械受体的命运是必要的。先前的实验已经表明mec-3的表达可以分为两个阶段：最初的合成部分由unc-86介导，继续合成需要mec-3本身。我们现在确定的序列，已保守的小杆线虫进化过程中，是必要的建立，维护和抑制mec-3的表达。mec-3编码序列的起始密码子上游是71、29、28和24 bp的四个片段（区域I-IV），它们在C. elegans和普通隐杆线虫（Caesiumhabditis vulgarensis）。区域I是影响mec-3合成建立的唯一保守序列。mec-3表达的维持主要由区域II介导。抑制似乎由几个片段控制：mec-3-lacZ融合体中III区、IV区和I区部分的突变导致mec-3阳性细胞的一些非mec-3表达姐妹篇中β-半乳糖苷酶表达。这些结果表明mec-3 5'区含有介导定型细胞谱系中姐妹细胞表达的替代命运之间的遗传转换的靶序列。
The homeo box-containing genes mec-3 and unc-86 are necessary to specify the fate of a defined set of mechanoreceptors in Caenorhabditis elegans. Previous experiments have shown that mec-3 expression can be divided into two phases: initial synthesis mediated in part by unc-86, and continued synthesis that requires mec-3 itself. We now identify sequences that have been conserved during Caenorhabditis evolution and are necessary for establishment, maintenance, and repression of mec-3 expression. Upstream of the start codon for the mec-3-coding sequence are four segments (regions I-IV) of 71, 29, 28, and 24 bp, which are almost identical between C. elegans and Caenorhabditis vulgarensis. Region I is the only conserved sequence that effects establishment of mec-3 synthesis. Maintenance of mec-3 expression is mediated primarily by region II. Repression appears to be controlled by several segments: Mutation of region III, region IV, and parts of region I in a mec-3-lacZ fusion results in beta-galactosidase expression in some non-mec-3-expressing sisters of mec-3-positive cells. These results indicate that the mec-3 5' region contains target sequences that mediate a genetic switch between alternative fates expressed by sister cells in a stereotyped cell lineage.