Activity of the ovarian germinal epithelium in the freshwater catfish, Pimelodus maculatus (Teleostei: Ostariophysi: Siluriformes): Germline cysts, follicle formation and oocyte development

2011 ◽  
Vol 272 (11) ◽  
pp. 1290-1306 ◽  
Author(s):  
Irani Quagio-Grassiotto ◽  
Harry Grier ◽  
Talita Sarah Mazzoni ◽  
Rafael Henrique Nóbrega ◽  
João Paulo de Arruda Amorim
Keyword(s):  
Oocyte Development ◽  
Germinal Epithelium ◽  
Freshwater Catfish ◽  
Pimelodus Maculatus

scholarly journals First report of the characterization of the pathophysiological mechanisms caused by the freshwater catfish Pimelodus maculatus (order: Siluriformes)

Toxicon ◽  
2015 ◽  
Vol 101 ◽  
pp. 55-62 ◽  
Author(s):  
Beatriz Elena Sarmiento ◽  
Marisa Rangel ◽  
Jacqueline Coimbra Gonçalves ◽  
Lilibete Pereira ◽  
Solange Rego ◽  
...  
Keyword(s):  
Pathophysiological Mechanisms ◽  
First Report ◽  
Freshwater Catfish ◽  
Pimelodus Maculatus

scholarly journals Ergasilus chelangulatus sp. nov. (Copepoda: Ergasilidae) a branchial parasite of the freshwater catfish, Pimelodus maculatus from the upper São Francisco River, Brazil

2008 ◽  
Vol 25 (3) ◽  
pp. 512-514 ◽  
Author(s):  
Vernon E. Thatcher ◽  
Marilia C. Brasil-Sato
Keyword(s):  
New Species ◽  
Freshwater Fish ◽  
Antennal Segment ◽  
Minas Gerais ◽  
The Body ◽  
Freshwater Catfish ◽  
Sao Francisco River ◽  
São Francisco River ◽  
Minas Gerais State ◽  
Pimelodus Maculatus

Ergasilus chelangulatus sp. nov. is described from the freshwater fish, Pimelodus maculatus Lacépède, 1803 (Siluriformes: Pimelodidae) of the upper São Francisco River, Minas Gerais State, Brazil. The new species is based on female specimens and the male is unknown. This species has a serrate seta on exopod one and a two-segmented first endopod, as do most Amazonian species of this genus. The body is elongate and produced anteriorly. The antennae are elongate and have prominent sensilla on segments two and three. Ergasilus chelangulatus sp. nov. can be distinguished from all known species of Ergasilus by the fourth antennal segment (claw) which is bent at nearly a right angle.

scholarly journals A new vision of the origin and the oocyte development in the Ostariophysi applied to Gymnotus sylvius (Teleostei: Gymnotiformes)

2010 ◽  
Vol 8 (4) ◽  
pp. 787-804 ◽  
Author(s):  
Gisleine Fernanda França ◽  
Harry J. Grier ◽  
Irani Quagio-Grassiotto
Keyword(s):  
Basement Membrane ◽  
Ovarian Follicle ◽  
Secondary Growth ◽  
Germinal Vesicle ◽  
Oocyte Development ◽  
Follicle Cells ◽  
Germinal Epithelium ◽  
Germinal Vesicle Breakdown ◽  
Vitellogenic Stage ◽  
New Vision

Based on new knowledge coming from marine perciform species, the origin of oocytes and their development in the Ostariophysi, Gymnotus sylvius is described. In both Gymnotus sylvius and marine perciform fish, oogonia are found in the germinal epithelium that forms the surface of the ovarian lamellae. At the commencement of folliculogenesis, proliferation of oogonia and their entrance into meiosis gives rise to germ cell nests that extend into the stroma from the germinal epithelium. Both cell nests and the germinal epithelium are supported by the same basement membrane that separates them from the stroma. At the time of meiotic arrest, oocytes in a cell nest become separated one from the other as processes of prefollicle cells, these being derived from epithelial cells in the germinal epithelium, gradually encompass and individualize them while also synthesizing a basement membrane around themselves during folliculogenesis. The oocyte enters primary growth while still within the cell nest. At the completion of folliculogenesis, the oocyte and follicle cells, composing the follicle, are encompassed by a basement membrane. The follicle remains connected to the germinal epithelium as the both share a portion of common basement membrane. Cells originating from the stroma encompass the ovarian follicle, except where there is a shared basement membrane, to form the theca. The follicle, basement membrane and theca form the follicular complex. Oocyte development occurs inside the follicular complex. Development is divided into the stages primary and secondary growth, oocyte maturation and ovulation. Cortical alveoli appear in the ooplasm just prior to the beginning of secondary growth, the vitellogenic stage that begins with yolk deposition and proceeds until the oocyte is full-grown and the ooplasm is filled with yolk globules. Maturation is characterized by the germinal vesicle or nuclear migration, germinal vesicle breakdown or nuclear envelop fragmentation and the resumption of meiosis. At the ovulation the egg is released from the follicular complex into the ovarian lumen. When compared to marine Perciformes that lay pelagic eggs, oocyte development in Gymnotus sylvius has fewer steps within the stages of development, the two most remarkable being the absence of oil droplet formation during primary and secondary growth, (and the consequent absence of the oil droplets fusion during maturation), and the hydrolysis of yolf preceding ovulation.

Impact of captive conditions on female germinal epithelium of the butterflyfish Chaetodon striatus (Perciformes: Chaetodontidae)

Zygote ◽  
2021 ◽  
pp. 1-12
Author(s):  
Talita Sarah Mazzoni ◽  
Graziele Cristine da Silva ◽  
Isabelle Leite Bayona Perez ◽  
Irani Quagio-Grassiotto
Keyword(s):  
Basement Membrane ◽  
Reproductive Biology ◽  
Cell Structure ◽  
Natural Habitat ◽  
Oocyte Development ◽  
Germinal Epithelium ◽  
Follicular Atresia ◽  
Glucose Levels ◽  
In Captivity ◽  
The Difference

Summary Chaetodon striatus is a cosmopolitan seawater species present in aquaria all over the world and its extractivism is quite high. The lack of studies on the reproductive biology of C. striatus contributes to the difficulty in managing the species outside its natural habitat. Without knowledge of the mechanisms that control or affect gonadal changes, reproduction of C. striatus in captivity has become almost impossible, considering that the species is quite sensitive and the effect of captive conditions on its reproductive biology is unknown. Therefore, this study aimed to evaluate the effect on its reproductive biology of the animal’s confinement and possible alteration in structure of the ovaries. In C. striatus, after oocyte development, for animals confined in small spaces, maturing oocytes undergo atresia. During atresia, ovarian follicles were at different stages of degeneration, characterized by the progressive loss of the basement membrane and disorganization of the follicle complex. In the advanced stage of follicular atresia, there was total loss of the basement membrane, culminating in degradation of the follicle complex. In unconfined animals, oocyte development and maturation were not affected. Confinement also affected the cell structure of the germinal epithelium, which showed large numbers of apoptotic bodies. The difference in cortisol and glucose levels between the unconfined and confined groups was significant, which may have to do with the change found in the ovaries, such as extensive follicular atresia and loss of the basement membrane.

Binucleate Spermiogenesis in the Mouse

1972 ◽  
Vol 30 ◽  
pp. 112-113
Author(s):  
John J. Wolosewick
Keyword(s):  
Electron Microscopy ◽  
Phosphate Buffer ◽  
Seminiferous Epithelium ◽  
Mouse Testis ◽  
Germinal Epithelium ◽  
Intercellular Bridges ◽  
Adult Mice ◽  
Cervical Dislocation ◽  
Human And Mouse

Classically, the male germinal epithelium is depicted as synchronously developing uninucleate spermatids conjoined by intercellular bridges. Recently, binucleate and multinucleate spermatids from human and mouse testis have been reported. The present paper describes certain developmental events in one type of binucleate spermatid in the seminiferous epithelium of the mouse.Testes of adult mice (ABP Jax) were removed from the animals after cervical dislocation and placed into 2.5% glutaraldehyde/Millonig's phosphate buffer (pH 7.2). Testicular capsules were gently split and separated, exposing the tubules. After 15 minutes the tissue was carefully cut into cubes (approx. 1mm), fixed for an additional 45 minutes and processed for electron microscopy.

Structures Resembling Striated Rootlets in Oocytes

1972 ◽  
Vol 30 ◽  
pp. 124-125
Author(s):  
Valerie V. Ernst
Keyword(s):  
Golgi Complex ◽  
Fibrous Structure ◽  
Oocyte Development ◽  
The Cross

During the earliest stage of oocyte development in the limpet, Acmea scutum, Golgi complexes are small, few and randomly dispersed in the cytoplasm. As growth proceeds, the Golgi complexes increase in size and number and migrate to the periphery of the cell. At this time, fibrous structures resembling striated rootlets occur associated with the Golgi complexes. Only one fibrous structure appears to be associated with a Golgi complex.The fibers are periodically cross banded with an average of 4 dense fibrils and 6 lighter fibrils per period (Fig. 1). The cross fibrils have a center to center spacing of about 7 run which appears to be the same as that of the striated rootlets of the gill cilia in this animal.

Ultrastructural Study of Human Testicular Biopsies in Infertility

1976 ◽  
Vol 34 ◽  
pp. 156-157
Author(s):  
Shirley Siew ◽  
Philip Troen ◽  
Howard R. Nankin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Basement Membrane ◽  
Leydig Cells ◽  
Clinical Evidence ◽  
Young Male ◽  
Germinal Epithelium ◽  
Transmission Electron ◽  
Age Range ◽  
Male Subjects

Testicular biopsies were obtained from six young male subjects (age range 24-33) who complained of infertility and who had clinical evidence of oligospermia. This was confirmed on histological examination which showed a broad spectrum from profound hypospermatogenesis to relatively normal appearing germinal epithelium. Thickening of the tubular walls was noted in half of the cases and slight peritubular fibrosis in one. The Leydig cells were reported as normal or unremarkable.Transmission electron microscopy showed that the thickening of the supporting tissue of the germinal epithelium was caused more by an increase in the thickness of the layers of the lamina propria than of the tubular wall itself. The changes in the basement membrane of the tubular wall consisted mostly of a greater degree of infolding into the tubule and some reduplication which gave rise to a multilayered appearance.

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