Department of Animal and Poultry Sciences, Virginia Tech. Blacksburg 24061.
Department of Animal and Poultry Sciences, Virginia Tech. Blacksburg 24061.
Poult Sci. 2020 May;99(5):2342-2348. doi: 10.1016/j.psj.2019.12.052. Epub 2020 Mar 18.
Goblet cells secrete mucin 2 (Muc2), which is a major component of the mucus that lines the intestinal tract and creates a protective barrier between pathogens and the intestinal epithelial cells and thus are important for chick health. The objectives of this study were to determine the age-specific and intestinal segment-specific expression of Muc2 mRNA and changes in the number of goblet cells from late embryogenesis to early after hatch. Small intestinal samples from the duodenum, jejunum, and ileum were collected from Cobb 500 broilers at embryonic day 19 (e19), day of hatch (doh), and day 2 and 4 after hatch. Cells expressing Muc2 mRNA and mucin glycoprotein were detected by in situ hybridization or alcian blue and periodic acid-Schiff staining, respectively. Along the villi, there were many more cells expressing Muc2 mRNA than those stained for mucin glycoprotein. In the crypt, cells expressing Muc2 mRNA did not stain for mucin glycoprotein. There was an increase in the density of goblet cells in the villi and Muc2 mRNA expressing cells in the crypts of the jejunum and ileum from e19 to doh and day 2 to day 4, with no change between doh and day 2. In contrast, in the duodenum, the density of goblet cells in the villi and Muc2 mRNA expressing cells in the crypts remained constant from e19 to day 4. At day 4, the villi in the ileum had a greater density of goblet cells than the duodenum. In the crypt, the ileum had a greater density of Muc2 mRNA expressing cells than the duodenum at doh, and the ileum and jejunum both had greater densities of Muc2 mRNA expressing cells than the duodenum at day 4. These results indicate that the population of goblet cells has reached a steady state by doh in the duodenum, whereas in the jejunum and ileum, a steady-state population was not reached until after hatch.
杯状细胞分泌黏蛋白 2（Muc2），它是肠道衬里黏液的主要成分，在病原体和肠上皮细胞之间形成保护屏障，因此对雏鸡的健康很重要。本研究的目的是确定 Muc2 mRNA 的年龄特异性和肠道节段特异性表达，并研究从胚胎晚期到孵化后早期杯状细胞数量的变化。从小鸡的十二指肠、空肠和回肠中收集 Cobb 500 肉鸡在胚胎第 19 天（e19）、孵化日（doh）以及孵化后第 2 天和第 4 天的样本。通过原位杂交或阿尔辛蓝和过碘酸希夫染色分别检测表达 Muc2 mRNA 和黏蛋白糖蛋白的细胞。沿着绒毛，表达 Muc2 mRNA 的细胞比那些染色为黏蛋白糖蛋白的细胞多得多。在隐窝中，表达 Muc2 mRNA 的细胞不染色黏蛋白糖蛋白。从 e19 到 doh 以及从第 2 天到第 4 天，空肠和回肠的绒毛中杯状细胞的密度以及隐窝中表达 Muc2 mRNA 的细胞密度增加，而 doh 和第 2 天之间没有变化。相比之下，在十二指肠中，从 e19 到第 4 天，绒毛中杯状细胞的密度以及隐窝中表达 Muc2 mRNA 的细胞密度保持不变。在第 4 天，回肠的绒毛比十二指肠的杯状细胞密度更大。在隐窝中，doh 时回肠的 Muc2 mRNA 表达细胞密度大于十二指肠，第 4 天时回肠和空肠的 Muc2 mRNA 表达细胞密度均大于十二指肠。这些结果表明，在十二指肠中，杯状细胞的数量在 doh 时已达到稳定状态，而在空肠和回肠中，直到孵化后才达到稳定状态。
