This study report about the differentiation of pancreatic acinar tissue in grass snake, Natrix natrix, embryos using light microscopy, transmission electron microscopy, and immuno‐gold labeling. Differentiation of acinar cells in the embryonic pancreas of the grass snake is similar to that of other amniotes. Pancreatic acini occurred for the first time at Stage VIII, which is the midpoint of embryonic development. Two pattern of acinar cell differentiation were observed. The first involved formation of zymogen granules followed by cell migration from ducts. In the second, one zymogen granule was formed at the end of acinar cell differentiation. During embryonic development in the pancreatic acini of N. natrix, five types of zymogen granules were established, which correlated with the degree of their maturation and condensation. Within differentiating acini of the studied species, three types of cells were present: acinar, centroacinar, and endocrine cells. The origin of acinar cells as well as centroacinar cells in the pancreas of the studied species was the pancreatic ducts, which is similar as in other vertebrates. In the differentiating pancreatic acini of N. natrix, intermediate cells were not present. It may be related to the lack of transdifferentiation activity of acinar cells in the studied species. Amylase activity of exocrine pancreas was detected only at the end of embryonic development, which may be related to animal feeding after hatching from external sources that are rich in carbohydrates and presence of digestive enzymes in the egg yolk. Mitotic division of acinar cells was the main mechanism of expansion of acinar tissue during pancreas differentiation in the grass snake embryos.

中文翻译：

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草蛇 Natrix natrix（鳞龙目，蛇）胚胎中胰腺腺泡的发育

本研究报告了使用光学显微镜、透射电子显微镜和免疫金标记对草蛇、Natrix natrix、胚胎中胰腺腺泡组织的分化。草蛇胚胎胰腺腺泡细胞的分化与其他羊膜动物相似。胰腺腺泡第一次出现在第 VIII 阶段，这是胚胎发育的中点。观察到两种腺泡细胞分化模式。第一个涉及酶原颗粒的形成，然后是细胞从导管迁移。第二，在腺泡细胞分化结束时形成一个酶原颗粒。在 N. natrix 胰腺腺泡的胚胎发育过程中，建立了五种类型的酶原颗粒，这与其成熟和凝结的程度相关。在所研究物种的分化腺泡中，存在三种类型的细胞：腺泡、中心腺泡和内分泌细胞。所研究物种胰腺中腺泡细胞和中心腺泡细胞的起源是胰管，这与其他脊椎动物相似。在 N. natrix 的分化胰腺腺泡中，不存在中间细胞。这可能与研究物种中腺泡细胞缺乏转分化活性有关。外分泌胰腺的淀粉酶活性仅在胚胎发育结束时检测到，这可能与从富含碳水化合物的外部来源孵化后的动物喂养和蛋黄中存在消化酶有关。