| stages in follicle cell/oocyte interface during vitellogenesis in caecilians ichthyophis tricolor and gegeneophis ramaswamii: a transmission electron-microscopic study. | we describe the ultrastructural organization of the vitellogenic follicle stages in two caecilian species. monthly samples of slices of ovary of ichthyophis tricolor and gegeneophis ramaswamii from the western ghats of india were subjected to transmission electron-microscopic analysis, with special attention to the follicle cell/oocyte interface. in order to maintain uniformity of the stages among the amphibians, all the stages in the caecilian follicles were assigned to stages i-vi, the vitello ... | 2008 | 18030494 |
| assembly of ovarian follicles in the caecilians ichthyophis tricolor and gegeneophis ramaswamii: light and transmission electron microscopic study. | though much is known about various aspects of reproductive biology of amphibia, there is little information on the cellular and mechanistic basis of assembly of ovarian follicles in this group. this is especially true of the caecilians. therefore, taking advantage of the abundant distribution of caecilians in the western ghats of india, two species of caecilians, ichthyophis tricolor and gegeneophis ramaswamii, were subjected to light and transmission electron microscopic analysis to trace the s ... | 2007 | 17637101 |
| ultrastructural observations of previtellogenic ovarian follicles of the caecilians ichthyophis tricolor and gegeneophis ramaswamii. | the ultrastructural organization of the previtellogenic follicles of the caecilians ichthyophis tricolor and gegeneophis ramaswamii, of the western ghats of india, were observed. both species follow a similar seasonal reproductive pattern. the ovaries contain primordial follicles throughout the year with previtellogenic, vitellogenic, or postvitellogenic follicles, depending upon the reproductive status. the just-recruited primordial follicle includes an oocyte surrounded by a single layer of fo ... | 2007 | 17345639 |
| antigenic homogeneity of male müllerian gland (mg) secretory proteins of a caecilian amphibian with secretory proteins of the mammalian prostate gland and seminal vesicles: evidence for role of the caecilian mg as a male accessory reproductive gland. | whereas in all other vertebrates the müllerian ducts of genetic males are aborted during development, under the influence of müllerian-inhibiting substance, in the caecilian amphibians they are retained as a pair of functional glands. it has long been speculated that the müllerian gland might be the male accessory reproductive gland but there has been no direct evidence to this effect. the present study was undertaken to determine whether the caecilian müllerian gland secretory proteins would be ... | 2014 | 25160003 |
| spermiogenesis in caecilians ichthyophis tricolor and uraeotyphlus cf. narayani (amphibia: gymnophiona): analysis by light and transmission electron microscopy. | spermiogenesis, known as spermateleosis in lower vertebrates, is the transformation of the round spermatid into a highly specialized spermatozoon with a species-specific structure. spermateleosis and sperm morphology of two species of caecilians, ichthyophis tricolor and uraeotyphlus cf. narayani, from the western ghats of kerala, india, were studied using light and transmission electron microscopy. spermateleosis is described in early, mid-, and late phases. during the early phase, the spermati ... | 2004 | 15352204 |
| stages in spermatogenesis of two species of caecilians, ichthyophis tricolor and uraeotyphlus cf. narayani (amphibia: gymnophiona): light and electron microscopic study. | the sequential changes during spermatogenesis in the testis of two species of caecilians, ichthyophis tricolor (ichthyophiidae) and uraeotyphlus cf. narayani (uraeotyphliidae), of western ghats of kerala, india, were traced using both histological techniques and transmission electron microscopy. the cell nests were assigned to stages in spermatogenesis based on the classification of van oordt (1956, thesis, utrecht university). to the best of our knowledge, this is the first identification and u ... | 2004 | 15164370 |
| sertoli cells in the testis of caecilians, ichthyophis tricolor and uraeotyphlus cf. narayani (amphibia: gymnophiona): light and electron microscopic perspective. | the caecilians have evolved a unique pattern of cystic spermatogenesis in which cysts representing different stages in spermatogenesis coexist in a testis lobule. we examined unsettled issues relating to the organization of the caecilian testis lobules, including the occurrence of a fatty matrix, the possibility of both peripheral and central sertoli cells, the origin of sertoli cells from follicular cells, and the disengagement of older sertoli cells to become loose central sertoli cells. we su ... | 2003 | 14584033 |
| light and electron microscopic observations on the organization of skin and associated glands of two caecilian amphibians from western ghats of india. | we adopted light and electron microscopy to understand the structure of the skin of two species of caecilians, ichthyophis tricolor and uraeotyphlus cf. oxyurus, from western ghats of kerala, india. the surface of the skin of these caecilians contains an irregular pattern of microridges. oval, round and polymorphic glandular openings are randomly distributed all over the skin surface. most of the openings are funnel shaped. the epithelial cells along the rim of the opening descend into the tunne ... | 2018 | 29353148 |