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Secretory granules produced by the Mehlis' gland and by the wall of the distal ootype in Schistosoma haematobium females, were examined at the ultrastructural level by means of several cytochemical methods. Strong staining, due to a relatively high percentage of carbohydrates in the granules, was observed in polymethacrylate sections treated with a phosphotungstic acidhydrochloric acid mixture at pH ≈ 0.5. Staining with ferric chloride-mixed-diamine mixtures (the LID and the HID reaction) showed no detectable level of oligosaccharide carboxyl and sulphate groups. A periodic acid-thiocarbohydrazide-silver proteinate reaction which was performed on epoxy sections, revealed a relatively high level of glycopyranosidic 1,2-diol groups in the granules. These results as well as the sensitivity of the secretory granules to the proteolytic action of papain indicated that the secretions produced by the Mehlis' gland and by the ootype wall were neutral glycoproteins.
In this work, clover was shown to respond to infection with Rhizobium leguminosarum bv. trifolii by producing reactive oxygen species. Superoxide radical and hydrogen peroxide were detected in infection threads and nodule primordia. The role of reactive oxygen species in clover-Rhizobium leguminosarum bv. trifolii symbiosis is discussed
Vitellogenesis in Wenyonia virilis was examined by transmission electron microscopy (TEM), including the cytochemical detection of glycogen at the ultrastructural level with the periodic acid-thiosemicarbazide-silver proteinate (PA-TSC-SP) technique. Mature vitelline follicles have cells in various stages of development, progressing from immature cells of gonial type near the periphery of the follicle to maturing and mature vitellocytes towards the centre. Maturation is characterized by: (1) increase in cell volume; (2) increase in nuclear surface area restoring the N/C (nucleo-cytoplasmic) ratio; (3) nucleolar transformation; (4) extensive development of parallel cisternae of GER, the shell-protein producing units; (5) development of Golgi complexes, engaged in shell-granule/shell-globule formation and packaging; (6) synthesis and storage of glycogen in the cytoplasm; (7) simultaneous, independent formation and storage of intranuclear glycogen; (8) continuous fusion of small shell-granules into larger shell-globules and fusion of these into large shell-globule clusters with a progressive increase in the number and size of the latter; and (9) disintegration of GER in the medial layer of vitellocyte cytoplasm, degenerative changes and accumulation of glycogen and shell-globule clusters within the cytoplasm. The functional significance of numerous shell-globule clusters and the relatively small amount of nuclear and cytoplasmic glycogen is analysed. Unlike vitellogenesis of other caryophyllids, the nuclear glycogen of mature vitellocytes in W. virilis is randomly dispersed in the nucleoplasm and never forms a high central accumulation, the so-called “nuclear vacuole”. The nutritive function of vitellocytes appears greatly reduced in W. virilis, a fact perhaps related to the intrauterine development of the early embryos. The ultrastructure of vitellogenesis in W. virilis is compared with that in other lower cestodes, both monozoic and polyzoic. Conclusions concerning interrelationships of the vitellogenesis pattern of the ultrastructural cytochemistry of mature vitellocytes of W. virilis to intrauterine embryonation, absence of uterine glands and an extensive uterus characteristic for this species, are drawn and discussed.
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