Starck J M
Zoologisches Institut, Spezielle Zoologie, Eberhard-Karls-Universität, Tübingen, Deutschland.
Acta Anat (Basel). 1996;156(4):289-306.
This paper introduces the comparison of altricial and precocial birds as a model system for the study of patterns of intestinal growth. It reports on comparative morphometric and cytokinetic studies of intestinal growth in altricial European starling (Sturnus vulgaris) and precocial Japanese quail (Coturnix coturnix japonica). Morphometric data at five gut segments of neonates and adults of both species are provided to evaluate the growth of the intestine. A double labelling technique combining 3H-thymidine autoradiography with 5-bromo-2'-deoxy-uridine immunohistochemistry gives labelling index, length of S-phase, and tissue turnover time for hatchlings and adults of both species. The results of morphometry show a similar pattern of intestinal growth in both species, a strong dependency of intestinal growth on body size, and a clear topographic separation of areas of cell proliferation from the functional mucosal epithelium. The results of the cytokinetic experiments indicate a constant length of the S-phase independent of species, development, and age. The 3H-thymidine labelling index is significantly higher in neonate quail than in neonate starling. Between adult animals of both species, the labelling index goes not differ significantly except for the duodenum which has a higher index in starling. The turnover time necessary to replace the mucosal epithelium is 3 days in hatchlings of both species and ranges between 10 and 17 days in adults. A diurnal pattern of cell proliferation, as previously reported in adult quail, is not present in neonate quail. Thus, differences in intestinal growth among altricial and precocial birds are primarily based on size differences of proliferation areas whilst cellular proliferation rates have only minor impact on intestinal growth. The short turnover time and the high rates of proliferation suggest that the intestine is a flexible organ that may be adjusted in size and function to the actual needs of the growing bird.
本文介绍了以晚成鸟和早成鸟作为模型系统来研究肠道生长模式的比较。报告了对晚成鸟欧洲椋鸟（Sturnus vulgaris）和早成鸟日本鹌鹑（Coturnix coturnix japonica）肠道生长的比较形态测量和细胞动力学研究。提供了两种鸟类幼鸟和成鸟五个肠道节段的形态测量数据，以评估肠道的生长情况。结合³H-胸腺嘧啶核苷放射自显影术与5-溴-2'-脱氧尿苷免疫组织化学的双重标记技术，得出了两种鸟类幼鸟和成鸟的标记指数、S期长度和组织更新时间。形态测量结果表明，两种鸟类的肠道生长模式相似，肠道生长强烈依赖于体型大小，并且细胞增殖区域与功能性黏膜上皮在地形上有明显分离。细胞动力学实验结果表明，S期长度恒定，与物种、发育阶段和年龄无关。³H-胸腺嘧啶核苷标记指数在幼鹌鹑中显著高于幼椋鸟。在两种成年动物之间，除了椋鸟十二指肠的标记指数较高外，标记指数没有显著差异。替换黏膜上皮所需的更新时间在两种幼鸟中均为3天，在成年鸟中为10至17天。如先前在成年鹌鹑中所报道的细胞增殖昼夜模式，在幼鹌鹑中并不存在。因此，晚成鸟和早成鸟肠道生长的差异主要基于增殖区域的大小差异，而细胞增殖速率对肠道生长的影响较小。较短的更新时间和较高的增殖速率表明，肠道是一个灵活的器官，其大小和功能可以根据生长中鸟类的实际需求进行调整。
