Histological and ultrastructural studies of the marsupial Didelphis albiventris Peyer's patches

Abstract

Differing from the studied Eutheria the white belly opossum Peyer's patches do not present a conspicuous dome. M cells are located in the inner layer of bilaminal formed at the bottom of the villi. A great variation in the morphology of M cells was observed. The enterocytes located at the epithelial inner layer may present endocytic vesicles, and the microvilli are shorter than the microvilli of enterocytes lining the small intestine. As these morphological aspects have been described to exist in the enterocytes of the lactent opossum small intestine it was surmised that the opossum Peyer's patches special epithelium could represent the persistence in adult animals of a cellular pattern established before the intestinal maturation had occurred.

The immune tissues of the endangered red‐tailed phascogale (Phascogale calura)

“…Although these lack dome regions, Antechinus species, opossums, dunnarts and phascogales may or may not have villi above the follicles. The presence of villi above the follicles in Dasyurids may suggest the presence of M cells similar to those observed in opossums (Coutinho et al. 1990).…”

“…Although these lack dome regions, Antechinus species, opossums, dunnarts and phascogales may or may not have villi above the follicles. The presence of villi above the follicles in Dasyurids may suggest the presence of M cells similar to those observed in opossums (Coutinho et al 1990). By contrast, tammar wallabies lack defined Peyer's patches but do have accumulations of lymphocytes (Basden et al 1997;Old & Deane, 2002a); rufous hare-wallabies (Lagorchestes hirsutus) appear to have Peyer's patches only when in diseased states (Young et al 2003) and northern brown bandicoots appear to have several different types, including lymphocyte aggregations distributed along the length of the intestine, clumps of lymphocyte aggregations and Peyer's patches (Old & Deane, 2002b).…”

A Histological Investigation of the Lymphoid and Immunohaematopoietic Tissues of the Adult Stripe-Faced Dunnart <i>(Sminthopsis macroura)</i>

“…In the koala, brushtail and ringtail possums Peyer's patches with distinct mantle zones, dome regions and caps were observed . In contrast, the white-bellied opossum [Coutinho et al, 1993[Coutinho et al, , 1994 and Antechinus species [Poskitt et al, 1984a-c] Old/Selwood/Deane the white-bellied opossum [Coutinho et al, 1990]. It would appear that adult stripe-faced dunnart has the capacity to respond to antigen exposure to gut-derived antigens.…”

“…In general, however, the histological appearance of the major lymphoid tissues resembles that seen in eutherians. This has been documented, to varying degrees, in the American polyprotodont opossums, Monodelphis domestica [Stone et al, 1996], Didelphis virginiana [Block, 1964] and Didelphis albiventris [Coutinho et al, 1990] and a number of Australian diprotodonts and polyprotodonts including the common antechinus, Antechinus stuartii and Antechinus swainsonii [Poskitt et al, 1984a-c], the tammar wallaby, Macropus eugenii [Basden et al, 1996], the quokka, Setonix brachyurus [Yadav et al, 1972a, b], the brushtail possum, Trichosurus vulpecula and the koala, Phascolarctos cinereus . Most recently the availability of species cross-reactive antibodies to lymphocyte-associated antigens has permitted a more specific analysis of the lymphocyte populations in the lymphoid tissues of D. albiventris [Coutinho et al, 1994], the koala, the brushtail possum and the ringtail possum, Pseudocheirus peregrinus , the northern brown bandicoot, Isoodon macrourus [Cisternas and Armati, 1999] and the eastern grey kangaroo (Macropus giganteus) [Old and Deane, 2001].…”

Comparative Phylogeny of the Mucosa-Associated Lymphoid Tissue

“…PP were examined in two species of marsupial mice (Antechinus swainsonii and Antechinus stuartii), where there were fewer PP, but with more numerous follicles. A South American opossum (Didelphis albiventris) also has PP, but they are unusual in that they do not have a conspicuous dome and the M cells are at the bases of the villi around the follicles (Coutinho et al, 1990). Subsequent immunohistology in the same species showed that there were T cells in the epithelium and in the PP, and that interestingly, the PP were well formed while the newborn opossums were still in the pouch (Coutinho et al, 1994).…”