Hayashi K, Yasugi S, Mizuno T
Zoological Institute, Faculty of Science, University of Tokyo, Japan.
Development. 1988 Aug;103(4):725-31. doi: 10.1242/dev.103.4.725.
Proventricular (glandular stomach) mesenchyme of chicken embryos can induce endoderms of some parts of embryonic digestive tract to produce embryonic chicken pepsinogen (ECPg), a marker protein for the differentiation of embryonic proventricular epithelium. In the present study, we investigated the production of ECPg mRNA in the course of epithelial-mesenchymal interactions between endoderms of digestive tract and proventricular mesenchyme. ECPg mRNA was detected by Northern hybridization with ECPg cDNA as a probe. In normal development of the proventriculus, ECPg mRNA was first detected at day 7 of incubation, and it ceased to be produced by day 21. Embryonic esophagus, gizzard and small intestine did not contain ECPg mRNA. When 6-day esophagus, gizzard or proventricular endoderm was associated and cultured with 6-day proventricular mesenchyme, the recombinates formed proventricular-gland-like complex glands and produced ECPg mRNA in almost equal quantity. However, 6-day small intestinal or 3.5-day allantoic endoderm did not produce pepsinogen mRNA under the same conditions, though the recombinates formed complex glands. These results indicate that the proventricular mesenchyme can induce de novo transcription of ECPg gene in esophagus, proventricular and gizzard endoderms, and that ECPg gene in small intestinal and allantoic endoderms fails to react to the inducing signal.
鸡胚腺胃间充质可诱导胚胎消化道某些部位的内胚层产生胚胎鸡胃蛋白酶原（ECPg），这是胚胎腺胃上皮分化的一种标记蛋白。在本研究中，我们调查了消化道内胚层与腺胃间充质之间上皮 - 间充质相互作用过程中ECPg mRNA的产生情况。以ECPg cDNA为探针，通过Northern杂交检测ECPg mRNA。在腺胃的正常发育过程中，ECPg mRNA在孵化第7天首次被检测到，并在第21天停止产生。胚胎食管、肌胃和小肠不含ECPg mRNA。当6日龄的食管、肌胃或腺胃内胚层与6日龄的腺胃间充质联合培养时，重组体形成腺胃样复合腺体，并产生几乎等量的ECPg mRNA。然而，在相同条件下，6日龄小肠或3.5日龄尿囊内胚层虽形成复合腺体，但不产生胃蛋白酶原mRNA。这些结果表明，腺胃间充质可诱导食管、腺胃和肌胃内胚层中ECPg基因的从头转录，而小肠和尿囊内胚层中的ECPg基因对诱导信号无反应。
