Borthwick Casey R, Old Julie M
Water and Wildlife Ecology, School of Science and Health, Hawkesbury Campus, Western Sydney University, Penrith, New South Wales, Australia.
Anat Rec (Hoboken). 2016 Feb;299(2):207-19. doi: 10.1002/ar.23297. Epub 2015 Dec 18.
Red-tailed phascogale (Phascogale calura) pouch young at birth were relatively underdeveloped in comparison with their eutherian counterparts, and the lymphoid tissues of the immune system were found to be histologically immature. The phascogale thymus rapidly developed in the first few days of pouch life and was quickly populated with lymphocytes. By the end of pouch life, involution of the thymus was underway. The bone marrow started to develop in the early stage of pouch life, although adipocytes and megakaryocytes were not observed until slightly later. The liver was hematopoietic from birth and reached histological maturity toward the end of pouch life. The lymph nodes were difficult to detect macroscopically because of their small size, but were easily identified microscopically later in pouch life, particularly in the mesentery, and these lymph nodes exhibited germinal centers by the end of pouch life. The early spleen was predominately mesenchymal, but exhibited some erythropoiesis. Follicles with well-developed germinal centers were not observed until the latest stage of pouch life. Although intraepithelial lymphocytes were detected in the intestines early in pouch life, the discrete lymphoid aggregates and Peyer's patches characteristic of the gut-associated lymphoid tissue (GALT) were not detected until later in pouch life. This is the first report of histological development in phascogale pouch young, as well as the first report of the thymus, bone marrow, and lymph nodes in this dasyurid species at any age.
与有胎盘类动物的幼崽相比，红尾袋鼬（Phascogale calura）出生时的育儿袋幼崽相对发育不全，且免疫系统的淋巴组织在组织学上不成熟。袋鼬的胸腺在育儿袋生活的头几天迅速发育，并很快有淋巴细胞聚集。到育儿袋生活结束时，胸腺开始退化。骨髓在育儿袋生活的早期开始发育，不过直到稍晚些时候才观察到脂肪细胞和巨核细胞。肝脏从出生起就具有造血功能，并在育儿袋生活接近尾声时达到组织学成熟。淋巴结由于体积小，肉眼很难检测到，但在育儿袋生活后期很容易在显微镜下识别，尤其是在肠系膜中，这些淋巴结在育儿袋生活结束时出现生发中心。早期的脾脏主要是间充质的，但有一些红细胞生成。直到育儿袋生活的最后阶段才观察到具有发育良好生发中心的滤泡。尽管在育儿袋生活早期在肠道中检测到上皮内淋巴细胞，但直到育儿袋生活后期才检测到肠道相关淋巴组织（GALT）特有的离散淋巴聚集物和派尔集合淋巴结。这是关于袋鼬育儿袋幼崽组织学发育的首次报告，也是关于这种袋鼬科物种在任何年龄的胸腺、骨髓和淋巴结的首次报告。
