Extracellular matrix of different composition supports the various splenic compartments of guinea fowl ( Numida meleagris).
The extracellular matrix (ECM) of the spleen of the guinea fowl has been studied by immunohistochemistry. Each splenic compartment contains a different composition of ECM. Reticular-fiber-specific collagen III is expressed by the red pulp and thymus-dependent periarterial lymphatic sheath, but silver impregnation reveals a reticular-fiber-like structure in the periellipsoidal white pulp (PWP) where collagen III is absent. The penicillar capillaries of one central artery are enveloped by a single branching sheath or sleeve: the ellipsoid or Schweigger-Seidel sheath. The shape of the sleeve shows more resemblance to a deer antler than to an ellipsoid; it emerges at the beginning of the penicillar capillaries and ends at the edge of the PWP. It is wrapped by a novel discontinuous basement-membrane-like structure that expresses tenascin and that is named the capsule of the Schweigger-Seidel sheath (CSS). The cuboidal-shaped inner cell layer of the ellipsoid can be identified by a novel monoclonal antibody: BID3. BID3-positive stellate-shaped cells also occur in the PWP, suggesting that this cell population has migratory capability. Monoclonal antibody KIF8 recognizes an ECM component in the ellipsoid not only of guinea fowl, but also of chicken and quail, and may thus identify an ellipsoid-specific antigen. Collagen I is associated with both the basement membrane of the penicillar capillary and the CSS, whereas collagen III is present only in the CSS. Laminin is expressed in the red pulp, but its staining pattern does not indicate the presence of the "ring fibers", which suggests the absence of sinuses. Fibronectin is the only ECM molecule studied that occurs in every splenic compartment, indicating extensive intrasplenic cell migration.
Gumati
Mohamed Khalifa
MK
Department of Human Morphology and Developmental Biology, Faculty of Medicine, Semmelweis University, Tuzoltó Street 58, 1094, Budapest, Hungary.
Magyar
Attila
A
Nagy
Nándor
N
Kurucz
Eva
E
Felföldi
Balázs
B
Oláh
Imre
I
D000375:Aging / Q000502:physiology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D001717:Birds / Q000033:anatomy & histology* / Q000378:metabolism; D005109:Extracellular Matrix / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D007150:Immunohistochemistry; D013154:Spleen / Q000033:anatomy & histology* / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure
D000911:Antibodies, Monoclonal