Modulation of gene expression in the embryonic digestive tract of C-elegans
Modulation of gene expression in the embryonic digestive tract of C-elegans
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DOI：
10.1006/dbio.1996.0218
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发表时间：
1996-09-15
影响因子：
2.7
通讯作者：
McGhee, JD
中科院分区：
文献类型：
--
作者：
Fukushige, T;Schroeder, DF;McGhee, JD
秀丽隐杆线虫消化道由来自不同细胞谱系的四个不同模块组成：来自 ABa 谱系的前咽、来自 MS 谱系的后咽、来自 E 谱系的肠道和来自 ABp 谱系的直肠。线虫肠道酯酶基因 (ges-1) 通常在胚胎肠道或 E 谱系中表达。然而，通过删除ges-1启动子中一对串联的WGATAR位点，可以将ges-1的表达转入胚胎咽和尾部的细胞中。在这里，我们使用激光消融实验和遗传分析来表明表达 WGATAR 删除的 ges-1 转基因的细胞属于消化道的所有三个非肠谱系：ABa、MS 和 ABp。我们还表明，WGATAR 删除的 ges-1 转基因或未删除的 ges-1 对照转基因产生的 ges-1 mRNA 转录物的分子大小和空间分布似乎受到正确调节，表明 ges-1 表达的空间转换发生在转录起始水平。我们进一步表明，WGATAR 删除和未删除的 ges-1 转基因都对一系列改变早期卵裂球命运的母体效应基因（skn-1、mex-1、pie-1 和 pop-1）的突变做出适当的反应。此外，WGATAR 缺失的 ges-1 转基因的咽部/尾部表达因合子基因 pha-4 的突变而被消除。最后，我们使用不精确的转座子切除来产生两个独立的线虫菌株，其具有 1 至 2 kb 的删除，从内源染色体 I 基因的启动子中删除串联 WGATAR 位点：在这两种菌株中，ges-1 不在胚胎肠道中表达，但在胚胎咽细胞中表达；咽部表达较弱，但无可争议。总体而言，我们的结果验证了先前对 ges-1 对照的转基因分析，并进一步表明 ges-1 似乎以系统特异性而非谱系特异性的方式受到调节。 ges-1表达的多个方面提供了研究如何从不同的细胞谱系建立多组分器官系统（例如消化道）的机会。 (C) 1996 学术出版社
The Caenorhabditis elegans digestive tract is composed of four distinct modules derived from separate cell lineages: anterior pharynx from the ABa lineage, posterior pharynx from the MS lineage, gut from the E lineage, and rectum from the ABp lineage. The C. elegans gut esterase gene (ges-1) is normally expressed in the embryonic gut or E lineage. However, expression of ges-1 can be switched into cells of the embryonic pharynx and tail by virtue of deleting a tandem pair of WGATAR sites in the ges-1 promoter. Here, we use both laser ablation experiments and genetic analysis to show that cells expressing the WGATAR-deleted ges-1 transgene belong to all three nongut lineages of the digestive tract: ABa, MS, and ABp. We also show that the molecular size and spatial distribution of ges-1 mRNA transcripts produced by either the WGATAR-deleted ges-1 transgene or the undeleted ges-l control transgene appear correctly regulated, suggesting that the spatial switch in ges-1 expression occurs at the level of transcription initiation. We further show that both the WGATAR-deleted and the undeleted ges-1 transgenes respond appropriately to mutations in a series of maternal effect genes (skn-1, mex-1, pie-1, and pop-1) that alter early blastomere fate. Moreover, the pharynx/tail expression of the WGATAR-deleted ges-1 transgene is abolished by mutations in the zygotic gene pha-4. Finally, we use imprecise transposon excision to produce two independent C, elegans strains with 1- to 2-kb deletions that remove the tandem WGATAR sites from the promoter of the endogenous chromosomal I gene: in both of these strains, ges-1 is not expressed in the embryonic gut but is expressed in cells of the embryonic pharynx; pharynx expression is weak but incontrovertible. Overall, our results validate previous transgenic analysis of ges-1 control and show further that ges-1 appears to be regulated in a system-specific, rather than a lineage-specific, manner. The multiple facets of ges-l expression provide an opportunity to investigate how a multicomponent organ system such as the digestive tract is established from diverse cell lineages. (C) 1996 Academic Press, Inc.