Related Experiment Video
Updated: Apr 30, 2026
12:02
Using TgVtg1:mcherry Zebrafish Embryos to Test the Estrogenic Effects of Endocrine Disrupting Compounds
Published on: August 8, 2020
6.0K
Artificial masculinization in tilapia involves androgen receptor activation.
Matan Golan1, Berta Levavi-Sivan1
1Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
General and Comparative Endocrinology
|May 13, 2014
Summary
Synthetic androgens like 17-α-methyltestosterone (MT) are used to produce all-male tilapia, but their mechanism is unclear. This study shows androgens are crucial for sex inversion, unlike natural differentiation.
Area of Science:
- Aquaculture
- Endocrinology
- Fish Biology
Background:
- Estrogens drive natural female tilapia differentiation; lack of steroids leads to male development.
- Synthetic androgens, such as 17-α-methyltestosterone (MT), are effective for producing all-male tilapia in aquaculture.
- The mechanism of synthetic androgen sex inversion is debated: androgenic activity vs. aromatase inhibition.
Purpose of the Study:
- To differentiate between androgenic activity and aromatase inhibition in synthetic androgen sex inversion.
- To evaluate the contribution of each mechanism to the sex inversion process.
- To aid the search for novel sex inversion agents.
Main Methods:
- In vitro inhibition of aromatase activity by MT and dihydrotestosterone (DHT).
- Assessment of androgenic activity of MT by observing blue color development in Sciaenochromis fryeri fry.
- Administration of MT, DHT, fadrozole (aromatase inhibitor), and flutamide (androgen antagonist) to tilapia.
- Dose-dependent evaluation of flutamide's effect on sex inversion potency of MT, DHT, and fadrozole.
Main Results:
- MT and DHT inhibited aromatase activity in vitro; fadrozole was more effective.
- Flutamide reduced MT's androgenic activity (blue color) and sex inversion potency dose-dependently.
- MT, fadrozole, and DHT all efficiently inverted sex in tilapia.
- Flutamide reduced the sex inversion efficiency of MT, DHT, and fadrozole.
Conclusions:
- Androgen receptors play a critical role in sex inversion treatments.
- Blocking androgen receptors reduces the efficiency of sex inversion.
- Unlike natural differentiation, androgens (endogenous or exogenous) are essential for inducing testicular differentiation during these treatments.
Related Concept Videos
02:45The Ratio of X Chromosome to Autosomes
11.5K
In most organisms, sex is determined by the ratio of X and Y chromosomes. However, in some organisms, such as Drosophila and C.elegans, sex is determined by the ratio of the number of X chromosomes to the number of sets of autosomes. The Y chromosome in Drosophila is active but does not determine sex. It contains genes responsible for the production of sperms in adult flies.
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female...
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female...
11.5K
02:19The Y Chromosome Determines Maleness
7.0K
The Y chromosome is a sex chromosome found in several vertebrates and mammals, including humans. In addition to 22 pairs of autosomes, the human males have one X chromosome and one Y chromosome. In these organisms, the presence or absence of the Y chromosome determines the development of male traits.
Evolution
Around 300 million years ago, the two sex chromosomes diverged from two identical autosomal chromosomes. Over time, the Y chromosome has lost most of its genes, shrinking in size....
Evolution
Around 300 million years ago, the two sex chromosomes diverged from two identical autosomal chromosomes. Over time, the Y chromosome has lost most of its genes, shrinking in size....
7.0K