ABSTRACT The integuments of ten treefrog species of two genera from Scinaxnae - O. angrensis (Lutz, 1973), O. flavoguttata (Lutz & Lutz, 1939), O. humilis (Lutz & Lutz, 1954), O. perpusilla (Lutz & Lutz, 1939), O. v-signata (Lutz, 1968), Scinax hayii (Barbour, 1909), S. similis (Cochran, 1952), O. trapicheroi (Lutz & Lutz, 1954) and S. x-signatus (Spix, 1824) - were investigated using conventional and histochemical techniques of light microscopy, and polarized light microscopy. All integuments showed the basic structure of the anuran integument. Moreover, the secretory portions of exocrine glands, such as serous merocrine and apocrine glands, were found to be restricted to the spongious dermis. Lipid content occurred together with the heterogeneous secretory material of the glands with an apocrine secretion mechanism. In addition, clusters of these apocrine glands were present in the ventrolateral integument of some species. Melanophores were also visualized in all examined hylids. However, the occurrence of iridophores, detected through polarized light microscopy, varied according to the species. The Eberth-Katschenko layer occurred in the dorsal integument from both genera, but it was only present in the ventral integument of O. albicans, O. angrensis, O. flavoguttata, O. perpusilla and O. v-signata. Although the integument of all treefrogs showed the same basic structure, some characteristics were genus-specific; however, these features alone may not be used to distinguish both genera.

ABSTRACT The purpose of this study was to examine the ovaries and the oviduct of juvenile females of the broad-snouted caiman, Caiman latirostris (Daudin, 1802), using light microscopy, histochemical and immunocytochemical techniques. The ovarian cortex was observed to contain groups of germinative cells and abundant previtellogenic follicles at different stages of development. In previtellogenic follicles, the oocyte was surrounded by a single cuboidal layer of granulosa cells, supported by the theca layer. The theca was formed by a concentric layer containing collage nous fibers, predominantly type I, and several smooth muscle fibers. The inner perivitelline layer appeared as a narrow basophilic region between the oocyte and the granulosa. The ovarian medullary region of loose connective tissue contained blood and lymphatic vessels, as well as numerous lacunae, being covered by a simple squamous epithelium, supported by a thin layer of connective tissue. The oviduct of C. latirostris showed five histologically distinct regions: infundibulum, magnum, isthmus, uterus and vagina. The infundibulum was composed of an irregularly folded mucosa covered by a simple columnar epithelium with the presence of ciliated cells, weakly reactive to PAS staining. In the magnum, the mucosa was highly folded, and pseudostratified columnar epithelium contains mucous cells, which reacted positively to PAS staining. The isthmus was lining by an epithelium of ciliated and non-ciliated secretory cells, but no gland was visualized in mucosa. In the uterus, the folded mucosa was composed of a simple epithelium of high cylindrical cells and the lamina propria, which was predominantly formed by strongly birefringent fibers, but yellow-green weakly birefringent fibers were also present. The epithelium of the vagina contained intensely ciliated and non-ciliated cells, both of which were positive to PAS staining and no gland was observed in this region. Although the ovary and the oviduct showed some morphological particularities, they are similar to other crocodilians.

This work found the occurrence of a distinct sialic acid-rich polysaccharide in the sperm surface of the sea urchin Lytechinus variegatus, which differed significantly from a similar molecule found in the egg jelly. The sperm polysaccharide extracted by protease digestion was purified using anion exchange chromatography and characterized using agarose gel electrophoresis, gas chromatography/mass spectrometry and NMR spectroscopy. This polysaccharide was highly sulfated and composed almost exclusively of N-acetylneuraminic acid. In contrast, the sialic acid-rich polysaccharide from the egg jelly was composed of N-glycolylneuraminic acid and contains several other hexoses in its structure. This new molecule could help to characterize in further detail the mechanism of fertilization in the sea urchin model system. Sulfated polysaccharides from the jelly coat of sea urchins showed species-specificity in inducing the sperm acrosome reaction, providing an example of a signal transduction event regulated by the sulfated polysaccharide. The new sialic acid-rich polysaccharide found in the sperm head could represent a new molecule involved in the biology of the sea urchin fertilization.