scholarly journals Ovarian Development and Serum Steroid Hormone Profiles in Hatchery-bred Female Catfish Clarias macrocephalus (Gunther) during an Annual Reproductive Cycle

1997 ◽  
Vol 63 (6) ◽  
pp. 867-872 ◽  
Author(s):  
Josefa D. Tan-Fermin ◽  
Shigeho Ijiri ◽  
Hiroshi Ueda ◽  
Shinji Adachi ◽  
Kohei Yamauchi
Keyword(s):  
Reproductive Cycle ◽  
Ovarian Development ◽  
Steroid Hormone ◽  
Annual Reproductive Cycle ◽  
Clarias Macrocephalus

scholarly journals Testicular Histology and Serum Steroid Hormone Profiles in Hatchery-bred Catfish Clarias macrocephalus (Gunther) during an Annual Reproductive Cycle

1997 ◽  
Vol 63 (5) ◽  
pp. 681-686 ◽  
Author(s):  
Josefa D. Tan-Fermin ◽  
Takeshi Miura ◽  
Hiroshi Ueda ◽  
Shinji Adachi ◽  
Kohei Yamauchi
Keyword(s):  
Reproductive Cycle ◽  
Steroid Hormone ◽  
Annual Reproductive Cycle ◽  
Clarias Macrocephalus ◽  
Testicular Histology

Monthly variations in the profile of sex steroids and ovarian development of brook trout (Salvelinus fontinalis Mitchill) during the annual reproductive cycle in Tasmania

2015 ◽  
Vol 63 (3) ◽  
pp. 220 ◽  
Author(s):  
Shafaq Fatima ◽  
Mark Adams ◽  
Ryan Wilkinson
Keyword(s):  
Reproductive Cycle ◽  
Sex Steroids ◽  
Brook Trout ◽  
Ovarian Development ◽  
Gonadosomatic Index ◽  
Annual Reproductive Cycle ◽  
Total Fecundity ◽  
Mature Fish ◽  
Index Value ◽  
Monthly Variations

Control of maturation in all-female salmonid stock can be achieved by manipulating photoperiod. This initially requires an assessment of the annual reproductive cycle under ambient photoperiod. This study therefore describes the seasonal variations in ovarian development and plasma profiles of oestradiol-17β and testosterone during the second year of a population of female brook trout. It was found that fish recruited for maturation following the summer solstice in December. Shortening of photoperiod likely stimulated the brain–pituitary–gonadal axis for vigorous progress of ovarian development, as indicated by increasing levels of oestradiol-17β and gonadosomatic index values. The highest gonadosomatic index value (18.26 ± 1.1%) was observed in June. During July, eggs were released from mature females by manual stripping. Total fecundity was observed as 4266 ± 341 oocytes per mature fish. Profiles of sex steroids observed here were found to be finely entrained within the succession of seasonal photoperiod. This finding indicates that maturation suppression by photoperiod manipulation should be instigated before initiation of oocyte recruitment that commenced during December.

Annual reproductive cycle of the captive female Japanese sardineSardinops melanostictus: Relationship to ovarian development and serum levels of gonadal steroid hormones

1991 ◽  
Vol 108 (1) ◽  
pp. 21-29 ◽  
Author(s):  
M. Matsuyama ◽  
S. Adachi ◽  
Y. Nagahama ◽  
C. Kitajima ◽  
S. Matsuura
Keyword(s):  
Steroid Hormones ◽  
Reproductive Cycle ◽  
Ovarian Development ◽  
Serum Levels ◽  
Gonadal Steroid Hormones ◽  
Gonadal Steroid ◽  
Annual Reproductive Cycle

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.

Peptidergic neurohormonal systems in the basal hypothalamus of the ferret and the mink: Immunocytochemical study of variations during the annual reproductive cycle

1988 ◽  
Vol 251 (1) ◽  
pp. 153-159 ◽  
Author(s):  
L. Boissin-Agasse ◽  
G. Alonso ◽  
G. Roch ◽  
J. Boissin
Keyword(s):  
Reproductive Cycle ◽  
Immunocytochemical Study ◽  
Annual Reproductive Cycle
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