Influence of 17-Alpha Methyl Testosterone on Masculinization and Growth in Tilapia (Oreochromis mossambicus)

Marjani, Majid; Jamili, Shahla; Mostafavi, Pargol Ghavam; Ramin, Mahmoudreza; Mashinchian, A.

doi:10.3923/jfas.2009.71.74

Cited by 27 publications

(26 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the control group was not significant different (P>0.05) from the 40 mgMT/kg feed and 90 mgMT/kg feed. Marjan et al [17] found that 75 mgMT/kg gave the highest body weight gain which was 1.3 times higher than the control when they studied sex reversed O. mossambicus. Mateen [8] found 70 mgMT/kg to have the highest positive effect on the growth indices of O. niloticus.…”

Section: Discussionmentioning

confidence: 95%

“…This is consistent to what was reported by Okoko [35] on O. niloticus who obtained 99.3% males at 30 mgMT/kg feed but only 52% at 1, 200 mgMT/kg feed. Marjani et al [17] on O. mossambicus found 98% males at 75 mgMT/kg but only 79.4% males at100 mgMT/kg. Das et al [36] had 96% males at 60 mgMT/kg dose but 78.33% at 120 mgMT/kg feed.…”

Section: Discussionmentioning

confidence: 95%

“…In the sex reversal of Tilapia fish species, several dosages of MT have been used and recommended (50 mgMT/kg [22]; 40 mgMT/kg [23]; 60 mgMT/kg [24,25]; 75 mgMT/kg [17]. Higher doses have been reported to be deleterious and catabolic and therefore reduce growth instead of being anabolic in nature.…”

Section: Discussionmentioning

confidence: 99%

“…A gonadal examination technique was carried as described by Guerrero and Shelton [15] on a Nikon profile projector (V-12) (500X power). The presence of previtellogenic or vitellogenic oocytes and the lobular configuration revealed the ovary and testis, respectively and consequently the phenotypic sex [16] or intersex (gonads containing both ovarian and testicular tissues) [17].…”

Section: Sex Ratio Determinationmentioning

confidence: 99%

See 3 more Smart Citations

Growth, Reproduction and Sex Ratios in Oreochromis Andersonii (Castelnau, 1861) Fed with Varying Levels of 17α-Methyl Testosterone

As¹,

Kang'ombe²,

Kassam³

et al. 2012

J Aquacult Res Dev

View full text Add to dashboard Cite

Three different doses (40, 60 and 90 mgMT/kg feed) of 17α-methyl testosterone (MT) were administered to Oreochromis andersonii. Growth, reproduction and sex ratios were evaluated. The fish raised on 60 mgMT/kg feed had the highest final mean weight and this was significantly different (P<0.05) from other hormone doses. Additionally, the 60 mgMT/kg fed fish had the lowest fecundity and reproductive effort. Histological examination of the gonads did not show any differences between the control and MT fed fish. The gross margin ratio (GMR) of the control group was the highest (P<0.05). The proportion of males in MT treated groups deviated significantly from the control group although the percentage of males obtained from the 40 mgMT/kg feed (93.4%) and 60 mgMT/kg feed (94.4%) fish was insignificant (P>0.05). Furthermore, the highest dose used produced a significantly lower (P<0.05) male proportion (79.3%) than the other treatments. The anabolic effect of androgen MT diminished over time.Growth, Reproduction and Sex Ratios in Oreochromis Andersonii (Castelnau, 1861) The fish were provided with the prepared feed twice a day (10:00 and 15:00 hrs) daily except Sundays calculated at 5% live body weight of the fish. Fortnightly, a total of 160 fish (20 from each tank or 40 from each treatment) were weighed and lengths (standard length (SL) and total length (TL)) measured according to the procedures described by Skelton [13] after the fish were anaesthetized in 5g/l crude clove (Unilever South Africa Foods (Ptv) Ltd) to reduce stress. The experiment lasted for 119 days.At the end of the experiment all the fish were caught and their weights and lengths (SL and TL) determined. In addition, 20 fish (10 of each sex) were taken to the laboratory for gonad and liver extraction and weighing for maturity stage [14] (Table 2) and hepatosomatic index (HSI) calculation. The fish were sexed by checking the genital papillae with the help of the magnifying glass (Figure 2). The gonads were then fixed in 10% formalin in individual vials for later egg counting and diameter determination on an ocular scale mounted to the microscope (Nikon NFX-35) (500x power) after blotting them on paper.Further 20 gonads (10 of each sex) from every treatment were prepared for the histological examination by fixing them 10% formalin solution. They were then embedded in paraffin wax after dehydration in series of methanol (70, 80, 90, 100%) and sectioned in 3 µm and then stained with Haematoxylin and Eosin before they were mounted on slides with DPX mountant. The slides were then examined on the Olympus microscope (150X power) and a picture taken with Kodak camera. Sex ratio determinationOreochromis andersonii breeders were stocked in 250 m 2 semiconcrete pond at the sex ratio of 3:1 (female=71.191 ± 12.093 g: male=174.857 ± 19.828 g; mean ± SD). After twenty one (21) days, the eggs were recovered from the mouth of the four brooding female fish and were immediately taken to the indoor hatchery for incubation in the jars at 28°C with the help ...

show abstract

Section: Discussionmentioning

confidence: 95%

Section: Discussionmentioning

confidence: 95%

Section: Discussionmentioning

confidence: 99%

Section: Sex Ratio Determinationmentioning

confidence: 99%

See 2 more Smart Citations

Growth, Reproduction and Sex Ratios in Oreochromis Andersonii (Castelnau, 1861) Fed with Varying Levels of 17α-Methyl Testosterone

As¹,

Kang'ombe²,

Kassam³

et al. 2012

J Aquacult Res Dev

View full text Add to dashboard Cite

show abstract

“…The higher percentage of male population with higher amount of MT consumed was reported by Mainardes-Pinto et al (2000), Okoko (1996), Macinthos et al (1983), Marjani et al (2009) and Mengumphan et al (2006). MainardesPinto et al (2000) reported significantly higher male population with 30 mg MT than control diet while increasing the MT concentration to 60 mg further increase the male population to 98%.…”

Section: Discussionmentioning

confidence: 72%

Comparative evaluation of Carp testis as an alternative to 17 α-Methyltestosterone on Tilapia sex reversal

et al. 2015

View full text Add to dashboard Cite

17 α-Methyltestosterone (MT) is a commonly used synthetic androgen for the all male tilapia fry production. The probable residual effect of MT on human health and environment has been a concern. Two trials for two seasons were conducted to evaluate the effectiveness of carp testis (CT), as a source of natural androgen, on sex reversal of Nile tilapia (Oreochromis niloticus) and compare it with MT at Department of Aquaculture, Agriculture and Forestry University, Nepal, using completely randomised block deign (RCBD). Altogether 8 treatments with 4 for methyltestosterone (40 mg MT kg -1 of diet) and 4 for 75% rohu (Labeo rohita) testis. Both source of androgen were fed for 15, 18, 21 or 24 days. Treatments were replicated thrice. The result of methyltestosterone feeding for 24 days showed significantly (p<0.05) higher percentage of male (98.5±1.5) than 15 days (87.1±3.5) but was statistically similar with 18 (91.8±2.6) and 21(94.3±3.0) days feeding. Similarly percentage of male obtained with18 (84.8 ±2.1) and 21 (85.8 ±2.9) days of CT feeding were statistically similar(p>0.05) with 24 days and also with 15 days CT treatment but the result of 24 days CT feeding was significantly higher (91.4 ±1.2) than 15 days (82.5 ±2.7) of carp testis feeding.

show abstract

Control of testes mass by androgen receptor paralogs in a cichlid

2021

View full text Add to dashboard Cite

Steroid hormones play numerous important and diverse roles in the differentiation and development of vertebrate primary and secondary reproductive characteristics.However, the exact role of androgen receptors (ARs)-which bind circulating androgens-in this regulatory pathway is unclear. Teleost fishes further complicate this question by having two paralogs of AR (ARa and ARb) resulting from a duplication of their ancestral genome. We investigated the functional role of these two ARs on testes growth and development by experimentally eliminating receptor function of one or both paralogs using CRISPR/Cas9 genome edited Astatotilapia burtoni, an African cichlid fish. Fish with two or more functional receptor alleles were more likely to be male compared to fish with one or fewer, suggesting that the two paralogs of the receptor may be redundant in regulating early sex determination. In contrast, we found that adult testes size was significantly affected by distinct combinations of mutant and wild-type AR alleles. We present a working model whereby ARb facilitates testes growth and ARa .

show abstract

Influence of 17-Alpha Methyl Testosterone on Masculinization and Growth in Tilapia (Oreochromis mossambicus)

Cited by 27 publications

References 5 publications

Growth, Reproduction and Sex Ratios in Oreochromis Andersonii (Castelnau, 1861) Fed with Varying Levels of 17α-Methyl Testosterone

Growth, Reproduction and Sex Ratios in Oreochromis Andersonii (Castelnau, 1861) Fed with Varying Levels of 17α-Methyl Testosterone

Comparative evaluation of Carp testis as an alternative to 17 α-Methyltestosterone on Tilapia sex reversal

Control of testes mass by androgen receptor paralogs in a cichlid

Contact Info

Product

Resources

About

Influence of 17-Alpha Methyl Testosterone on Masculinization and Growth in Tilapia (Oreochromis mossambicus)

Cited by 27 publications

References 5 publications

Growth, Reproduction and Sex Ratios in Oreochromis Andersonii (Castelnau, 1861) Fed with Varying Levels of 17α-Methyl Testosterone

Growth, Reproduction and Sex Ratios in Oreochromis Andersonii (Castelnau, 1861) Fed with Varying Levels of 17α-Methyl Testosterone

Comparative evaluation of Carp testis as an alternative to 17 &alpha;-Methyltestosterone on Tilapia sex reversal

Control of testes mass by androgen receptor paralogs in a cichlid

Contact Info

Product

Resources

About

Comparative evaluation of Carp testis as an alternative to 17 α-Methyltestosterone on Tilapia sex reversal