Two ParaHox genes, SpLox and SpCdx, interact to partition the posterior endoderm in the formation of a functional gut
Two ParaHox genes, SpLox and SpCdx, interact to partition the posterior endoderm in the formation of a functional gut
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DOI：
10.1242/dev.029959
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发表时间：
2009-02-15
期刊：
影响因子：
4.6
通讯作者：
Arnone, Maria I.
中科院分区：
文献类型：
--
作者：
Cole, Alison G.;Rizzo, Francesca;Arnone, Maria I.
我们报告的直向同源的爪蟾XlHbox8 ParaHox基因的海胆Strongylocentrotus puratus，SpLox的表征。它在胚胎发生期间表达，首先出现在内胚层管的最后区域中的原肠胚形成晚期，逐渐限于中肠和后肠之间的收缩。该基因的活性的情况下的生理效应已通过敲低实验使用基因特异性吗啉代反义寡核苷酸进行了分析。我们发现，阻断SpLox mRNA的翻译降低了消化道处理食物的能力，并消除了中肠和后肠之间通常存在的形态收缩。SpLox基因的遗传相互作用通过分析参与内胚层特化的一组基因的表达来揭示。两个这样的相互作用已进行了更详细的分析：一个涉及中肠标记基因Endo16，另一个涉及其他内胚层表达的ParaHox基因，SpCdx。我们发现，SpLox能够结合Endo16顺式调节DNA，这表明直接抑制Endo16在假定的后肠领土的表达。更重要的是，我们提供了第一个证据的ParaHox基因之间的相互作用，在建立后肠的身份，并提出了一个模型的基因调控，涉及负反馈回路。
We report the characterization of the ortholog of the Xenopus XlHbox8 ParaHox gene from the sea urchin Strongylocentrotus purpuratus, SpLox. It is expressed during embryogenesis, first appearing at late gastrulation in the posterior-most region of the endodermal tube, becoming progressively restricted to the constriction between the mid- and hindgut. The physiological effects of the absence of the activity of this gene have been analyzed through knockdown experiments using gene-specific morpholino antisense oligonucleotides. We show that blocking the translation of the SpLox mRNA reduces the capacity of the digestive tract to process food, as well as eliminating the morphological constriction normally present between the mid- and hindgut. Genetic interactions of the SpLox gene are revealed by the analysis of the expression of a set of genes involved in endoderm specification. Two such interactions have been analyzed in more detail: one involving the midgut marker gene Endo16, and another involving the other endodermally expressed ParaHox gene, SpCdx. We find that SpLox is able to bind Endo16 cis-regulatory DNA, suggesting direct repression of Endo16 expression in presumptive hindgut territories. More significantly, we provide the first evidence of interaction between ParaHox genes in establishing hindgut identity, and present a model of gene regulation involving a negative-feedback loop.