The investigation of back-transformation mechanisms of ringwoodite and majorite in the Yamato 75267 H6

The Tenth Symposium on Polar Science/Special session: [OA] Antarctic meteorites, Thur. 5 Dec. / 3F Multipurpose conference room, National Institute of Polar Researc

Profiles of mRNA Expression of FOXL2, P450arom, DMRT1, AMH, P450c17, SF1, ERα and AR, in Relation to Gonadal Sex Differentiation in Duck Embryo

The present study was conducted to show a profile of mRNA expression of sex-differentiation related genes in the duck gonad. Fertile duck eggs (Cherry-valley) were incubated (hatching at day 28 of incubation) and the gonads were collected at days 7, 8, 10, 12 and 15 of incubation after taking photos of the gonads. Left gonad was used for identification of genetic sex and for total RNA extraction. Reverse transcription-polymerase chain reaction (PCR) was performed using appropriate forward and reverse primers for each of FOXL2, P450arom, DMRT1, AMH, P450c17, SF1, ER α and AR genes of the chicken and the corresponding cDNA fragments were sequenced for duck. Subsequently, real-time PCR was performed to detect mRNA expression of those genes in the duck embryo. Male bilateral gonads assumed symmetry in appearance throughout the examined period, whereas the female gonads were noticeably asymmetric at 10 days of incubation with a smaller size of the right. Female asymmetry was distinct by day 15 of incubation. In females, FOXL2 and P450arom mRNA expression began at day 8 of incubation and remained high thereafter, but in males only negligible expression was detected. In males, mRNA expression of DMRT1 and AMH was detected at day 7 of incubation and tended to increase gradually thereafter, whereas in females the expression remained low throughout the examined period. Though the slight expression of P450c17 mRNA started at day 7 only in males, the expression was low throughout the examined period, whereas in female the expression was distinct at day 8 of incubation and remained high thereafter. Expressions of the other genes were variable with no differences in each expression between the sexes. The results indicate that FOXL2 and P450arom play an important role for the ovarian formation

Expression of P450arom, AMH and ERα mRNA in Gonads of Turkey, Duck and Goose within One Week of Age

Although many studies have shown that P450aromatase (P450arom), anti-Müllerian hormone (AMH) and estrogen receptor α (ERα) play pivotal roles in sexual differentiation of the gonads during early embryonic development in chickens and quail, few studies have been reported for other domestic birds. Furthermore, little information is available in relation to the mRNA expression in gonads after sexual differentiation in posthatching birds. The present study was conducted to assay mRNA expression of P450arom, AMH and ERα in gonads at day of hatch in turkey and duck and 2 days after hatching in goose using the real-time PCR. The mRNA expression was also determined at one week of age in gonads of these birds. At the time of collection of the left gonads for total RNA extraction, the external appearance of the left and right gonads of male and female was documented by digital camera. Clear asymmetry was observed in the female ovary in which the right ovary was regressed completely by 1-2 days in posthatching turkey, duck and goose. Although gonadal asymmetry was as remarkable as in females, the left testis was larger than the right one in males. Remarkable expression of P450arom mRNA was observed only in females in all the 3 species but substantially no expression was detected in males. Significantly higher expression of AMH mRNA was detected in males than females only in goose but there was no sex difference in turkey and duck at 1-2 days posthatching and one week of age. Weak ERα mRNA expression without a sex difference was detected in the 3 birds. These results suggest that estrogen plays a key role for ovarian development via P450arom mRNA expression after hatching, whereas absence of its expression in males leads to testis development in turkey, duck and goose