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.

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.

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.

Movement of nutrients in fungi. I. The Mycelium

1968 ◽  
Vol 16 (1) ◽  
pp. 71 ◽  
Author(s):  
LB Thrower ◽  
SL Thrower
Keyword(s):  
Nutrient Medium ◽  
Natural Habitat ◽  
Taxonomic Position ◽  
Deficient Medium ◽  
The Difference ◽  
Hyphal Apex

Thirty-one species of fungi (representing 13 orders) were examined for their ability to grow from a nutrient medium onto a non-nutrient medium; 17 were capable of colonizing the deficient medium, 10 were not, and 4 were indeterminate. The ability to grow onto deficient medium appeared to be related to the natural habitat of the fungus rather than to taxonomic position. Experiments with isotopically labelled nutrients showed that both colonizing fungi and non-colonizing fungi were capable of some transport of nutrients, the difference between the two groups being one of degree. In transporting fungi, labelled nutrients were moved more rapidly when the fungus colonized a deficient medium than when it colonized a nutrient medium; this suggested that movement of nutrients is adaptive to some extent. The importance of the growing hyphal apex as a sink for nutrients was demonstrated.

scholarly journals Brain Size of the African Grasscutter (Thryonomys Swinderianus, Temminck, 1827) at Defined Postnatal Periods

2017 ◽  
Vol 61 (4) ◽  
pp. 5-11 ◽  
Author(s):  
C. S. Ibe ◽  
S. O. Salami ◽  
N. Wanmi
Keyword(s):  
Cognitive Ability ◽  
Brain Size ◽  
Natural Habitat ◽  
Brain Weight ◽  
Strong Positive Correlation ◽  
Positive Correlation ◽  
Thryonomys Swinderianus ◽  
Physiological Studies ◽  
The Difference ◽  
The Brain

Abstract As a sequel to the current advancement in ethology, this study was designed to provide information on the brain size of the African grasscutter at specific postnatal periods and to extrapolate these findings to the behaviour of the rodent in its natural habitat. Brain samples were extracted from African grasscutter neonates on postnatal day 6, juveniles on postnatal day 72 and adults on postnatal day 450 by basic neuro-anatomical techniques. The weight, volume and dimensions of the brain samples were determined in absolute and relative terms. Their encephalisation quotient was also computed. There was a very strong positive correlation between nose-rump length and brain length in the neonates. The relative brain weight of neonates, juveniles and adults were 3.84 ± 0.12 %, 2.49 ± 0.07 % and 0.44 ± 0.03 %, respectively. The differences were significant (P < 0.05). The encephalisation quotient of juveniles was 1.62 ± 0.03 while that of the adult was 0.49 ± 0.02. The difference was significant (P < 0.05). The results were extrapolated to the animal’s cognitive ability, and compared with other rodents. It was concluded that the juvenile African grasscutter may have higher cognitive ability than the adult rodent, thus, juveniles should be preferred in physiological studies of memory and cognition.

Phenotypic Modulation of Smooth Muscle Cells after Arterial Injury Is Associated with Changes in the Distribution of Laminin and Fibronectin

1997 ◽  
Vol 45 (6) ◽  
pp. 837-846 ◽  
Author(s):  
Johan Thyberg ◽  
Karin Blomgren ◽  
Joy Roy ◽  
Phan Kiet Tran ◽  
Ulf Hedin
Keyword(s):  
Smooth Muscle ◽  
Basement Membrane ◽  
Smooth Muscle Cells ◽  
Actin Filaments ◽  
Cell Structure ◽  
Muscle Cells ◽  
Arterial Injury ◽  
Internal Elastic Lamina ◽  
Contractile Phenotype

Earlier in vitro studies suggest opposing roles of laminin and fibronectin in regulation of differentiated properties of vascular smooth muscle cells. To find out if this may also be the case in vivo, we used immunoelectron microscopy to study the distribution of these proteins during formation of intimal thickening after arterial injury. In parallel, cell structure and content of smooth muscle α-actin was analyzed. The results indicate that the cells in the normal media are in a contractile phenotype with abundant α-actin filaments and an incomplete basement membrane. Within 1 week after endothelial denudation, most cells in the innermost layer of the media convert into a synthetic phenotype, as judged by loss of actin filaments, construction of a large secretory apparatus, and destruction of the basement membrane. Some of these cells migrate through fenestrae in the internal elastic lamina and invade a fibronectin-rich network deposited on its luminal surface. Within another few weeks a thick neointima forms, newly produced matrix components replace the strands of fibronectin, and a basement membrane reappears. Simultaneously, the cells resume a contractile phenotype, recognized by disappearance of secretory organelles and restoration of α-actin filaments. These findings support the notion that laminin and other basement membrane components promote the expression of a differentiated smooth muscle phenotype, whereas fibronectin stimulates the cells to adopt a proliferative and secretory phenotype.

Reproductive behaviour and cross-mating of two closely related pygmy squids Idiosepius biserialis and Idiosepius thailandicus (Cephalopoda: Idiosepiidae)

2008 ◽  
Vol 88 (5) ◽  
pp. 987-993 ◽  
Author(s):  
Jaruwat Nabhitabhata ◽  
Jitima Suwanamala
Keyword(s):  
Reproductive Behaviour ◽  
Morphological Characters ◽  
Andaman Sea ◽  
Individual Species ◽  
Gulf Of Thailand ◽  
Separate Species ◽  
Behavioural Patterns ◽  
Sea Grass ◽  
In Captivity ◽  
The Difference

Idiosepius biserialis and Idiosepius thailandicus have been previously described as separate species although the difference in morphological characters is only the arrangement of pegs in tentacular-club suckers. The former species inhabits sea grass beds in the Andaman Sea of Thailand. The latter species inhabits mangroves in the eastern Gulf of Thailand. The present study of reproductive behaviour, mating, and spawning of the two species in captivity demonstrated that they are closely related. Copulation was performed using tentacles by the male for fixation of spermatophores at the buccal region of the female. Behavioural patterns were distinguished based on the hovering and adhering positions of each sex. Cross-mating between two species was initiated and observed, yielding fertilized eggs which developed to the organogenesis stage. Reproductive behaviour of crossed pairs was similar to those of individual species. This study revealed that the two ‘species’ are not reproductively isolated.

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