2017 Study Abstract
Induction of sex reversal of XY fish has been restricted to the sex undifferentiated period.
In the present study, differentiated XY tilapia were treated with trilostane (TR), metopirone (MN) and glycyrrhetinic acid (GA) (inhibitor of 3β-HSD, Cyp11b2 and 11β-HSD, respectively) alone or in combination with 17β-estradiol (E2) from 30 to 90 dah (days after hatching). At 180 dah, E2 alone resulted in 8.3%, and TR, MN and GA alone resulted in no secondary sex reversal (SSR), whereas TR + E2, MN + E2 and GA + E2 resulted in 88.3, 60.0 and 46.7% of SSR, respectively.
This sex reversal could be rescued by simultaneous administration of 11-ketotestosterone (11-KT). Compared with the control XY fish, decreased serum 11-KT and increased E2 level were detected in SSR fish. Immunohistochemistry analyses revealed that Cyp19a1a, Cyp11b2 and Dmrt1 were expressed in the gonads of GA + E2, MN + E2 and TR + E2 SSR XY fish at 90 dah, but only Cyp19a1a was expressed at 180 dah. When the treatment was applied from 60 to 120 dah, TR + E2 resulted in 3.3% of SSR, MN + E2 and GA + E2 resulted in no SSR.
These results demonstrated that once 11-KT was synthesized, it could antagonize E2-induced male-to-female SSR, which could be abolished by simultaneous treatment with the inhibitor of steroidogenic enzymes. The upper the enzyme was located in the steroidogenic pathway, the higher SSR rate was achieved when it was inhibited as some of the precursors, such as androstenedione, testosterone and 5α-dihydrotestosterone, could act as androgens. These results highlight the key role of androgen in male sex maintenance.
Image credit Rusty Clark.
Interesting study. I wonder how this could be applied to human males. As a intersex person I was born with one underdeveloped ovotestis and one underdeveloped so called normal testis. The ovotestis developed ovarian type cancer and was surgically reomove after chemotherapy. Years later my remaining testis is failing to work properly and my testosterone levels are falling down way below the acceptable levels.
Interesting enough I’ve never felt male and the idea of taking testosterone doesn’t sit well with me. I know I should take testosterone for therapy maintenance but I just cannot. I do not care for how I feel when taking even a low dose of testosterone and it became an emotional thing with me as well.
I wonder if there is a study group of researchers that need someone like myself?
for sure David ( hannah ), thank you