Polarized distribution of binding sites for concanavalin A and wheat-germ agglutinin in the zona pellucida of goodeid oocytes (teleostei)

Lectin-binding pattern of the Senegalese sole Solea senegalensis oogenesis

The glycoconjugate pattern of developing ovarian follicles in wild and cultured Senegalese sole Solea senegalensis was investigated by means of lectin histochemistry. Ovaries from cultured fish contained oocytes up to the late vitellogenic stage, whereas they reached the hydration stage in wild specimens. The follicular cells bound MAL II, SBA, HPA, DBA, Con A, KOH-sialidase (K-s)-WGA, GSA I-B(4) in the late vitellogenic stage, and in wild fish also SNA and K-s-PNA, whereas in the hydration stage SBA, HPA, DBA, and GSA I-B(4) only. The zona radiata reacted with SBA, HPA, DBA, Con A, and GSA I B(4) in the late vitellogenic stage and in cultured fish also with UEA I, whereas in the hydration stage it stained with SBA only. The cortical alveoli bound SBA, HPA, RCA(120) during the late vitellogenic stage, also SNA, PNA, K-s-PNA, GSA I-B(4) in cultured fish, DBA, and K-s-WGA in wild ones which stained with SBA, HPA, and GSA I-B(4) in the hydrated stage. The yolk reacted with Con A in the late vitellogenic oocytes, and also with MAL II, SNA, K-s-PNA, SBA, HPA, K-s-WGA, GSA I-B(4), UEA I in the hydrated ones. From perinucleolus to late vitellogenic stages, the oocyte nucleoplasm bound Con A, GSA I-B(4), GSA II, UEA I, and in wild fish also MAL II, SNA, LTA but only GSA I-B(4) reactivity in the early maturation stage. These findings demonstrate that the glycan pattern of fish ovarian follicles changes during the maturative stages and that it is affected by culture-rearing conditions.

Histological, histochemical and immunohistochemical study on the growing oocytes of the abyssal teleost Hoplostethus mediterraneus (V)

The oocytes of the abyssal Teleost, Hoplostethus mediterraneus were studied. Four stages of growth were observed and the oocytes of all the stages were surrounded by follicular cells and had several nucleoli in the nucleus. In the oocytes of the II degrees stage, vacuoles without contents, in oocytes of the III degrees stage several vacuoles with a basophilic contents and small yolk globules were identified. General and basic proteins, ribonucleoproteins, acid proteoglycans with -COOH groups were recognized in the cytoplasm, in the nucleoli of oocytes in the II degrees stage and in the vacuolar contents of oocytes in the III degrees stage. In the follicular cells, in the pellucid zone, in the yolk globules, from their beginning, glycoproteins were present. Positivity, for all lectins used, was revealed in the follicular cells and in the four stages of oocytes growth. alpha-D-glucose and alpha-D-mannose binding sites were in the pellucid zone and in the initial yolk globules. In the lather galactose and beta-N-acetyl glucosamine were present too. nNOS and VIP immunopositivity revealed at the periphery of the cytoplasm and at network of nerve fibres between oocytes, suggests NO is involved in a mechanism of regulation of the gametogenesis and of the spawning.