A analysis collaboration primarily based at Kumamoto College (Japan) has discovered that activation of PPARα, a fatty acid receptor that detects fatty acids in cells and regulates physiological capabilities, causes masculinization of Japanese rice fish (medaka). The invention of this molecular mechanism is anticipated to advance the event of latest intercourse management applied sciences.
The intercourse of mammals is set of their genes, particularly the XX/XY mixture of intercourse chromosomes. Alternatively, the sex-determination of fish, amphibians, and reptiles is drastically affected by ambient temperature. The medaka (Oryzias latipes), nevertheless, is a bony fish that uniquely makes use of the XX/XY intercourse dedication system.
The sex-determining gene, DMY, was just lately recognized on their Y chromosome. Usually, XY people with the DMY gene will differentiate into males and XX people (with out DMY) will differentiate into females. Nonetheless, if medaka are bred in water with temperatures of 32 to 34°C throughout their interval of sexual differentiation, XX people will differentiate into males. In different phrases, their genetic sex-determination is affected by temperature.
Earlier analysis from Kumamoto College demonstrated that cortisol, a high-temperature-induced stress hormone, instantly acts on the gonads and causes masculinization of XX medaka (Hayashi et al., 2010; Yamaguchi et al., 2010; Kitano et al., 2012). Nonetheless, the molecular mechanism of cortisol masculinization was not decided.
On this examine, researchers performed an RNA sequencing evaluation to seek for genes activated by excessive temperature or cortisol. Many genes associated to the fatty acid receptor “peroxisome proliferator-activated receptor alpha” (PPARα) had been detected, and when a PPARα activator was administered to medaka larvae, XX medaka grew to become male. Moreover, when knockout medaka with inhibited PPARα operate had been produced, differentiation into males was utterly suppressed, even after the administration of cortisol or a PPARα activator. To the researchers’ information, that is the primary time that PPARα activation has been proven to be so concerned with medaka sex-differentiation by cortisol or an activator.
In fish farming for meals manufacturing, corresponding to flounder or eel, know-how that produces solely females is wanted as a result of they develop quicker than males. Right here, now we have revealed the molecular mechanism that induces differentiation into males and we hope that new sexual management applied sciences utilizing this mechanism might be developed sooner or later.”
Professor Takeshi Kitano, Examine Chief
Hara, S., et al. (2020) Peroxisome proliferator-activated receptor alpha is concerned within the temperature-induced intercourse differentiation of a vertebrate. Scientific Stories. doi.org/10.1038/s41598-020-68594-y.