Relationship between seasonal plasma estradiol-17 beta and testosterone levels and in vitro production by ovarian follicles of amago salmon (Oncorhynchus rhodurus).
01 Sep 1983-Biology of Reproduction (Society for the Study of Reproduction)-Vol. 29, Iss: 2, pp 301-309
TL;DR: The seasonal pattern of plasma testosterone levels lagged behind and followed that of estradiol-17 beta during vitellogenesis, but levels remained high in mature and ovulated fish, and GSI values showed a linear increase, and reached a peak in October.
Abstract: Plasma estradiol-17 beta and testosterone levels were assessed by radioimmunoassay during the sexual maturation of female amago salmon (Oncorhynchus rhodurus). Estradiol-17 beta levels gradually increased during vitellogenesis (June to September), reached a peak in September (about 16 ng/ml) and rapidly decreased in mature and ovulated fish (about 3-4 ng/ml) in October. The seasonal pattern of plasma testosterone levels lagged behind and followed that of estradiol-17 beta during vitellogenesis, but levels remained high in mature and ovulated fish (90-110 ng/ml). Estradiol-17 beta levels and the gonadosomatic index (GSI) values correlated well during vitellogenesis: GSI values showed a linear increase, and reached a peak (29.9 +/- 1.4) in October. Values were extremely low in ovulated fish (1.2 +/- 0.2). In vitro production of estradiol-17 beta and testosterone by ovarian follicles in response to partially purified chinook salmon gonadotropin (SG-G100) was examined monthly using 18-h incubations. Throughout the vitellogenic period SG-G100 stimulated both estradiol-17 beta and testosterone production: the steroidogenic response of follicles increased from June (about 2 ng/ml estradiol-17 beta; 0.1 ng/ml testosterone) to September (about 10 and 14 ng/ml, respectively). In October full-grown immature follicles which could be induced to mature in vitro by hormone treatment produced large amounts of testosterone (about 130 ng/ml) but not estradiol-17 beta. Postovulatory follicles also produced testosterone but the values were low (10 ng/ml) compared with full-grown immature follicles. Very low levels of estradiol-17 beta were produced by postovulatory follicles.(ABSTRACT TRUNCATED AT 250 WORDS)
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TL;DR: In this paper , a study was performed to evaluate the efficacy of shrimp shell meal derived natural astaxanthin (SSM), supplemented with its commercial variant on gonadal maturation and vitellogenin gene (Vtg.) expression in reproductively active adults of the high-value ornamental cichlid discus ( Symphysodon aequifasciatus ) reared under captivity.
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TL;DR: It can be inferred that progesterone was considered as the critical index for seasonal breeding selection in Rohu Labeo rohita and there was an appropriate condition in the mid winter for broodstock selection and breeding of fish with hormones manipulation.
Abstract: Sex steroids (testosterone, progesterone and 17β-estradiol) play important roles in controlling reproduction and sexual maturity in teleosts. The aim of the present study was to evaluate the seasonal changes of these steroids in Rohu Labeo rohita. Forty gravid females and males L. rohita reared in different seasons (spring, summer, autumn, winter) were caught by a net with 1 cm mesh from earthen ponds of Aquaculture Research Institute, in south of Iran. The highest levels of 17β-estradiol (122.8±17.73 ng mL-1), testosterone (0.11±0.003 ng mL-1) and progesterone (0.86±0.01 ng mL-1) in female fish were recorded in autumn. In addition, the highest concentration of testosterone in male was determined as 0.84±0.003 ng mL-1 in autumn. The mean value of dissolved oxygen in four seasons (spring, summer, autumn, and winter) were 9.21±0.77, 8.36±0.51, 10.41±0.9 and 13.14±0.72 mg L-1, with temperature 25.47±1.07, 29.88±1.42, 20.23±0.69 and 14.63±0.47◦C, respectively. Therefore, it can be inferred that progesterone was considered as the critical index for seasonal breeding selection. There was an appropriate condition in the mid winter for broodstock selection and breeding of fish with hormones manipulation.
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Cites background from "Relationship between seasonal plasm..."
...…period of the reproductive cycle in females of several species, including Oncorhynchus mykiss (Scott et al., 1980), Oncorhynchus rhodurus (Kagawa et al., 1983), Catostomus commersoni (Scott et al., 1984), Acanthopagrus schlegeli (Chang and Yueh, 1990), Paralichthys dentatus (Merson et…...
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TL;DR: A strong non-linear relationship was found between oocyte size and 17β-oestradiol plasma concentration and especially between oocytes size and testosterone plasma concentration, which could likely be used to obtain information relative to the gonadal development in an endangered species like Salmo marmoratus, which needs non-invasive tools for management.
Abstract: The reproductive cycle of female wild marble trout Salmo marmoratus was studied in a prealpine watercourse (Northeast Italy). Gonadosomatic index, oocyte growth and plasma levels of 17β-oestradiol and testosterone were bimonthly measured during one year to obtain a detailed dataset and to gain useful tools for the identification of the reproductive stage without impact for the species. Monitored features showed significant variations during the study period: gonadosomatic index and oocyte size increased slightly but significantly during the first part of the cycle (from February to June), while steroid levels remained quite constant; for all parameters, major increases were highlighted between August and the spawning season (which occurred from the middle of November to the middle of December). Ranges and trends observed for gonadosomatic index (from 0.87 ± 0.41% to 10.91 ± 3.37%) and oocyte diameter (from 0.692 ± 0.031 mm to 4.624 ± 0.208 mm) were generally in agreement with literature regarding salmonids, while plasma levels of 17β-oestradiol (from 0.214 ± 0.015 ng ml−1 to 78.090 ± 23.882 ng ml−1) and testosterone (from 0.327 ± 0.086 ng ml−1 to 71.800 ± 29.406 ng ml−1) showed wider ranges. A strong non-linear relationship was found between oocyte size and 17β-oestradiol plasma concentration (r
2 = 0.890) and especially between oocyte size and testosterone plasma concentration (r
2 = 0.947). This last relationship could likely be used to obtain information relative to the gonadal development, especially in the case of an endangered species like Salmo marmoratus, which needs non-invasive tools for management.
1 citations
Cites background from "Relationship between seasonal plasm..."
...2015) on fish collected from hatcheries or from in vitro experiments (Kagawa et al. 1983; Kagawa 2013), instead of analysing wild specimens and/or studying another species....
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...2013) and its role as a precursor for the synthesis of E2 by aromatase activity in the ovary is well known (Fostier et al. 1983; Kagawa et al. 1983; Norberg et al. 1989; King and Pankhurst 2003; Kagawa 2013)....
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...Follicles produce E2 in response to gonadotropin stimulation, but as this production increases during oocyte growth, it decreases rapidly in association with the ability of the oocyte to mature (Kagawa et al. 1983; Young et al. 1983; Kanamori et al. 1988; Kagawa 2013)....
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...…almost all teleost fish species during the reproductive season (Fregeneda-Grandes et al. 2013) and its role as a precursor for the synthesis of E2 by aromatase activity in the ovary is well known (Fostier et al. 1983; Kagawa et al. 1983; Norberg et al. 1989; King and Pankhurst 2003; Kagawa 2013)....
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...…et al. 1998; Estay et al. 2003; Wilkinson et al. 2010; Estay et al. 2012; Fregeneda-Grandes et al. 2013; Taranger et al. 2015) on fish collected from hatcheries or from in vitro experiments (Kagawa et al. 1983; Kagawa 2013), instead of analysing wild specimens and/or studying another species....
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Journal Article•
TL;DR: Inci kefali Chalcalburnus tarichi, Pallas, 1811 postovulasyon folikullerinde apoptoz, TUNEL boyama ve agaroz jel elektroforez metodlari ile arastirildi ve plazma 17β-estradiol (E2) seviyesi ovulasyondan sonra 1., ve 5.
Abstract: Inci kefali Chalcalburnus tarichi, Pallas, 1811 postovulasyon folikullerinde apoptoz. Bu calismada, inci kefali (Chalcalburnus tarichi) postovulasyon folikullerinde apoptoz, TUNEL boyama ve agaroz jel elektroforez metodlari ile arastirildi ve plazma 17β-estradiol (E2) seviyesi ovulasyondan sonra 1., 3. ve 5. gunlerde belirlendi. Postovulasyon folikullerinde apoptotik hucreler, histolojik kesitlerde, ovulasyondan sonra 1. gunde isaretlendi ve apoptozun cogunlukla granuloza nadiren de teka hucrelerinde meydana geldigi belirlendi. Apoptozun isareti olan oligonukleozomal buyuklukteki DNA parcalanmasi ovulasyondan sonra 1., 3. ve 5. gunlerde gozlendi. Ovulasyon aninda oligonukleozomal DNA parcalanmasi gozlenmezken, 3. ve 5. gunlerde bu parcalanmanin belirgin oldugu goruldu. Plazma E2 seviyesi ovulasyondan sonra dereceli olarak dustu. Bu dusus 3. ve 5. gunlerde onemliydi (P
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Cites result from "Relationship between seasonal plasm..."
...These results are in aggreement with results of other studies on Salvenius leucomanis (Kagawa et al. 1981), Oncorhyncus rhodurus (Kagawa et al. 1983), Catosmus commersani (Scott et al. 1984) and Anchellgnathus rhombdea (Shimizu et al. 1985)....
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Dissertation•
01 Jan 2004
TL;DR: These studies demonstrate the commercial feasibility of androgens and AT for sex inversion of Atlantic salmon and the efficacy of immersion treatment with AT is dependent on both enzyme inhibition and the uptake and retention characteristics of AI.
Abstract: Commercial production of Atlantic salmon, Salmo solar (L.), in Tasmania is becoming increasingly reliant on female stocks for year round production. Hatchery production of female monosex stocks uses milt from sex inverted females ("neomales") to produce all female offspring. This study was undertaken investigate the effects of aromatase inhibitors (Al) on Atlantic salmon and to facilitate the development of techniques for their commercial application.
Dietary treatment for 800 °C days from first feeding, with methyltestosterone at doses of 1 or 3 mg kg\(^{-1}\) food or methyldihydrotestosterone (MDHT) at 1 mg kg\(^{-1}\) food resulted in 100% masculinisation of female Atlantic salmon. Masculinisation followed 2 h immersion of alevins in MDHT at 400 μg\(^{-1}\) during the period 0 to 28 days post median hatch (DPMH) and complete masculinisation was achieved after immersion at 14 and 21 or 14 and 28 DPMH. More sex inverted males with patent sperm ducts were produced by immersion than dietary treatments.
The capacity of five AI: 1,4,6-androstatriene-3,17-dione (ATD); 4-androstene-4- ol-3,17-dione (OHA); 142,4-dich1oro-β-([2,4-dichlorobenzyl]oxy)- phenethyl]imidazole (miconazole); 3[p-aminopheny1]-3-ethyl-piperidine-2,6- dione (aminoglutethimide) and 445,6,7,8-tetra-hydroimidazo-(1,5-α)-pyridin-5- yl] benzonitrile monohydrochloride (fadrozole) to reduce estradiol (E\(_2\)) production by Atlantic salmon brain and gonadal tissue was assessed in vitro. Fadrozole was the most potent, effective at doses of 0.1-10.0 μg ml\(^{-1}\). ATD, OHA and miconazole were also effective on brain and gonadal tissue, but aminoglutethimide was only effective on brain tissue.
Immersion of Atlantic salmon alevins in ATD at a dose of 0.5 mg L\(^{-1}\) on 14 or 14 and 28 DPMH produced 13% neomales. This incidence was increased to 47 and 22% following treatment on 7 and 14, or 14 and 21 DPMH respectively and to 51- 54% with a dose of 5 mg \(^{-1}\) ATD. Miconazole, aminoglutethimide, fadrozole and OHA were all ineffective for sex inversion. Precocious maturation was induced by photoperiod manipulation, and 67-88 % of mature neomales had patent sperm ducts and fertility (~70%) comparable to normal males.
ATD was taken up by alevins more readily than OHA; however, tissue levels of both declined by 50%, after 24 h and by >90% after 7 days. Uptake levels declined with alevin age, but retention rates were similar. Reducing the inter-treatment interval to 7 days resulted in increased androgen levels following the second treatment with ATD. Immersion in fadrozole at doses of 10 and 50 mg L\(^{-1}\) resulted in tissue levels of 300 and 1000 ng fish\(^{-1}\) which declined by 80% after 3 days.
These studies demonstrate the commercial feasibility of androgens and AT for sex inversion of Atlantic salmon. The efficacy of immersion treatment with AT is dependent on both enzyme inhibition and the uptake and retention characteristics of AI.
1 citations
Cites background from "Relationship between seasonal plasm..."
..., 1995), rainbow trout, Oncorhynchus mykiss (Carragher and Sumpter, 1990), amago salmon, Oncorhynchus rhodurus (Kagawa et al., 1983), where increased vitellogenic state and follicle size were associated with increased levels of E2 production....
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