Seasonal changes in pyloric caecum and gonad indices during the annual reproductive cycle in the seastar Asterias forbesi

1986 ◽  
Vol 91 (4) ◽  
pp. 553-560 ◽  
Author(s):  
D. R. Franz
Keyword(s):  
Reproductive Cycle ◽  
Seasonal Changes ◽  
Pyloric Caecum ◽  
Annual Reproductive Cycle ◽  
Asterias Forbesi

scholarly journals Seasonal changes in the pituitary gonadotrops during tha annual reproductive cycle of the Murrel Channa punctatus (Bloch)

1998 ◽  
Vol 12 (12) ◽  
pp. 17
Author(s):  
S. J. Srivastava ◽  
R. Singh
Keyword(s):  
Reproductive Cycle ◽  
Seasonal Changes ◽  
Channa Punctatus ◽  
Annual Reproductive Cycle

Foram observadas mudanças sazonais na estrutura e comportamento dos hormônios gonadotrópicos pituitários durante o ciclo reprodutivo anual de Channa punctatus. Os hormônios gonadotrópicos demonstram mudanças morfológicas marcantes na forma da granulação, degranulação e vacuolisação com o ciclo sexual sugerindo sua tendência de armazenamento e liberaçào durante atividades gonadais.

Seasonal changes in the protein profile and enzyme activity of the epididymal luminal fluid in the lizard, Eutropis carinata (Schneider, 1801)

2018 ◽  
Vol 68 (4) ◽  
pp. 387-404
Author(s):  
R. Medini ◽  
M. Bhagya ◽  
S. Samson
Keyword(s):  
Enzyme Activity ◽  
Reproductive Cycle ◽  
Seasonal Changes ◽  
Protein Profile ◽  
Periodic Acid ◽  
Active Phase ◽  
Surface Proteins ◽  
Protein Profiles ◽  
Annual Reproductive Cycle ◽  
Periodic Acid Schiff

Abstract The epididymis of the male reproductive system is known to be involved in sperm maturation via the production of polypeptides, glycoproteins, surface proteins, enzymes and other factors. During the annual reproductive cycle, the epididymis of the lizard Eutropis carinata undergoes dramatic changes, both morphologically and biochemically, that occur in a well-organized sequence. The present study reveals the sequential changes that occur in the production and concentration of proteins in the epididymal luminal fluid throughout the annual reproductive cycle. A one-dimensional electrophoretic profile of the epididymal luminal proteins revealed a total of 18 bands in the regenerative phase, 22 bands during breeding and 17 bands in the post-breeding as well as regressed phases of the reproductive cycle. By two-dimensional electrophoresis, the protein complexes that are unique to the breeding phase were further resolved based on their pI and the molecular weight of each protein of the protein complex was determined. This is the first study to observe that proteins that are present during the reproductively inactive phase disappear during the reproductively active phase. The Periodic Acid Schiff (PAS) test for protein profiles revealed the presence of proteins with a carbohydrate moiety. Certain enzymes, such as acid phosphatase, alkaline phosphatase, and α-glucosidase, are highly sensitive to seasonal changes and their activity parallels the production of the epididymal proteins. This study provides evidence for androgen-dependent cyclical changes in the pattern of protein profiles and enzyme activity of the epididymal lumen in the lizard E. carinata.

scholarly journals Seasonal changes in testicular and epididymal histology of the tropical lizard, Tropidurus itambere (Rodrigues, 1987), during its reproductive cycle

2009 ◽  
Vol 69 (2) ◽  
pp. 429-435 ◽  
Author(s):  
A. Ferreira ◽  
DN. Silva ◽  
M. Van Sluys ◽  
H. Dolder
Keyword(s):  
Electron Microscopy ◽  
Reproductive Cycle ◽  
Seasonal Changes ◽  
Seminiferous Tubule ◽  
Annual Reproductive Cycle ◽  
The Mean ◽  
Reproductive Cycles

The reproductive cycles of lizards, including Tropidurus species, have been widely studied. However, few studies describe in detail the ultrastructure and the epithelial changes in the epididymis. Using histology and trasmission electron microscopy, we show the seasonal changes in the testis and epididymis of the lizard Tropidurus itambere, during its annual reproductive cycle. The reproductive cycle of T. itambere was analysed from June 1988 to June 1989 and from June 2001 to June 2002. While the frequency of reproductive males in the population varied throughout the year, there were reproductive males in most months except for February through April. During this nonreproductive period, there is a reduction in the mean seminiferous tubule volume and few sperm were found in both the testis and the epididymis.

Mechanisms underlying pituitary microvascular remodelling in thoroughbred horses during the annual reproductive cycle

2014 ◽  
Author(s):  
Angus Yeomans ◽  
Nichol Thompson ◽  
Jennifer Castle-Miller ◽  
David O Bates ◽  
Domingo Tortonese
Keyword(s):  
Reproductive Cycle ◽  
Annual Reproductive Cycle ◽  
Thoroughbred Horses

scholarly journals Proliferative and Apoptotic Pathways in the Testis of Quail Coturnix coturnix during the Seasonal Reproductive Cycle

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1729
Author(s):  
Sara Falvo ◽  
Luigi Rosati ◽  
Maria Maddalena Di Fiore ◽  
Federica Di Giacomo Russo ◽  
Gabriella Chieffi Baccari ◽  
...  
Keyword(s):  
Reproductive Cycle ◽  
Second Messengers ◽  
Reproductive Period ◽  
Annual Reproductive Cycle ◽  
Coturnix Coturnix ◽  
Immunohistochemistry Analysis ◽  
17Β Estradiol ◽  
Apoptotic Pathways ◽  
Camp And Cgmp ◽  
Activation Phase

The quail Coturnix coturnix is a seasonal breeding species, with the annual reproductive cycle of its testes comprising an activation phase and a regression phase. Our previous results have proven that the testicular levels of both 17β-estradiol (E2) and androgens are higher during the reproductive period compared to the non-reproductive period, which led us to hypothesize that estrogens and androgens may act synergistically to initiate spermatogenesis. The present study was, therefore, aimed to investigate the estrogen responsive system in quail testis in relation to the reproduction seasonality, with a focus on the molecular pathways elicited in both active and regressive quail testes. Western blotting and immunohistochemistry analysis revealed that the expression of ERα, which is the predominant form of estrogen receptors in quail testis, was correlated with E2 concentration, suggesting that increased levels of E2-induced ERα could play a key role in the resumption of spermatogenesis during the reproductive period, when both PCNA and SYCP3, the mitotic and meiotic markers, respectively, were also increased. In the reproductive period we also found the activation of the ERK1/2 and Akt-1 kinase pathways and an increase in second messengers cAMP and cGMP levels. In the non-reproductive phase, when the E2/ERα levels were low, the inactivation of ERK1/2 and Akt-1 pathways favored apoptotic events due to an increase in the levels of Bax and cytochrome C, with a consequent regression of the gonad.

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