Department of Veterinary Anatomy, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Nigeria.
Department of Veterinary Physiology and Pharmacology, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Nigeria.
Anat Histol Embryol. 2022 Jan;51(1):136-142. doi: 10.1111/ahe.12774. Epub 2021 Dec 7.
Morphological development of the lamina epithelialis mucosae (LEM) of the ileum of broiler chicken was evaluated using light and transmission electron microscopic techniques. Ileal sections were collected on embryonic days (ED) 14, 17 and 19, as well as post-hatch days (PD) 1, 3, 5, 7, 14, 21, 28, 35, 42 and 56. The result showed that the ileal LEM, which were poorly defined at embryonic days 14 and 17, consisted of enterocytes and some atypically shaped goblet cells. Apico-lateral tight junctions and irregularly shaped microvilli were associated with the enterocytes at ED 14 and 17. The enterocyte microvilli were more uniform in shape and distribution at ED 19. The embryonic goblet cells were varied in shape and possessed basally displaced, star-shaped nuclei and small apical cytoplasmic vacuoles. During the post-hatch ages, the LEM was a typical epithelium with a single layer of columnar-shaped enterocytes that became highly elongated at post-hatch day (PD) 7. The goblet cells were characteristically 'wine-glass' shaped. Follicle-associated epithelium (FAE) showing numerous lymphocytes among the enterocytes occurred in the post-hatch LEM. The intra-epithelial lymphocytes (IEL) were first encountered at PD 1, but increased several folds within the first two weeks post-hatch. Entero-endocrine cells were observed in the epithelium from PD 21. Finally, from this study, it is obvious that enterocytes and small atypically shaped goblet cells occur in the ileal LEM during the pre-hatch period, but these cells assume adult morphological characteristics after hatch. Thus, the cells of the ileal LEM play strategic absorptive, secretory and protective roles in the gut.
采用光镜和透射电镜技术研究了肉鸡回肠黏膜上皮（LEM）的形态发育。在胚胎期 14、17 和 19 天以及出壳后 1、3、5、7、14、21、28、35、42 和 56 天收集回肠切片。结果表明，在胚胎期 14 天和 17 天，回肠 LEM 发育不良，由肠细胞和一些形状不规则的杯状细胞组成。顶侧紧密连接和不规则形状的微绒毛与 ED 14 和 17 的肠细胞有关。在 ED 19 时，肠细胞微绒毛的形状和分布更加均匀。胚胎杯状细胞形状多样，具有基底移位的星形核和小的顶端细胞质空泡。在出壳后的年龄，LEM 是一种具有单层柱状肠细胞的典型上皮，在出壳后第 7 天变得高度伸长。杯状细胞呈典型的“酒杯”形状。在出壳后的 LEM 中，滤泡相关上皮（FAE）显示肠细胞之间有许多淋巴细胞。上皮内淋巴细胞（IEL）在出壳后第 1 天首次出现，但在出壳后两周内增加了数倍。肠内分泌细胞在 PD 21 的上皮中观察到。最后，从这项研究中可以明显看出，在孵化前的肠 LEM 中存在肠细胞和小的形状不规则的杯状细胞，但这些细胞在孵化后呈现成人的形态特征。因此，回肠 LEM 的细胞在肠道中发挥着吸收、分泌和保护的战略作用。
