Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1095/biolreprod.103.016873
Titel (primär) Hormonal induction and stability of monosex populations in the medaka (Oryzias latipes): expression of sex-specific marker genes
Autor Scholz, S.; Rösler, S.; Schäffer, M.; Hornung, U.; Schartl, M.; Gutzeit, H.O.
Journal / Serie Biology of Reproduction
Erscheinungsjahr 2003
Department ZELLTOX
Band/Volume 69
Heft 2
Seite von 673
Seite bis 678
Sprache englisch
Keywords early development; embryo; estradiol; gene regulation; testis
Abstract The model teleost medaka (Oryzias latipes, d-rR.YHNI strain) was used to produce offspring of a defined sex (monosex populations) by crossing experimentally produced YY and XX males to normal females. These monosex populations had the predicted chromosomal constitution as shown by a sex chromosome-specific DNA sequence. However, in XX populations the spontaneous development of males without previous exposure to androgens was observed. Differences in the percentage of male offspring from individual XX breeding pairs indicate a possible variation of unknown genetic factors to be responsible for the development of XX males. The expression of two gonadal genes that are involved in sex differentiation, Dmrt1b(Y) and Fig1a (factor in the germ line ), was analyzed in monosex populations. Dmrt1b(Y) expression correlated strictly with the genotype but not the sexual phenotype. When XY juvenile fish were exposed to 17-ethynylestradiol at concentrations that induce sex reversal, Dmrt1b(Y) expression was not repressed. However, Dmrt1b(Y) was expressed in XY or YY gonads regardless of the sex and could not be detected in XX individuals. In contrast, the expression of Fig1a correlated with the phenotypic sex: Fig1a was expressed in male juvenile fish exposed to 17-ethynylestradiol and repressed in fish exposed to 17-methyltestosterone. The Dmrt1b(Y) expression appears to reflect an early and important event in sex determination and lends support to the suggested key regulatory role of the Dmrt1b(Y) gene in sex determination. This process is apparently hormone insensitive, and the expression of further downstream acting genes can be regulated (directly or indirectly) by sex steroids.
dauerhafte UFZ-Verlinkung
Scholz, S., Rösler, S., Schäffer, M., Hornung, U., Schartl, M., Gutzeit, H.O. (2003):
Hormonal induction and stability of monosex populations in the medaka (Oryzias latipes): expression of sex-specific marker genes
Biol. Reprod. 69 (2), 673 - 678