RRC ID 3827
Author Kurokawa H, Saito D, Nakamura S, Katoh-Fukui Y, Ohta K, Baba T, Morohashi K, Tanaka M.
Title Germ cells are essential for sexual dimorphism in the medaka gonad.
Journal Proc. Natl. Acad. Sci. U.S.A.
Abstract To further elucidate the roles of germ cells in the sex differentiation of gonads, we have used the medaka, a teleost fish, to generate mutants that lack germ cells from the onset of gonadogenesis by the morpholino-mediated knockdown of cxcr4. The resulting germ-cell-deficient medaka show female-to-male sex reversal of their secondary sex characteristics, accompanied by increased levels of androgen and reduced levels of estrogen. A failure to maintain granulosa cells or estrogen-producing cells also occurs at early stages of sex differentiation in the cxcr4 morphants, before the initiation of gonadal morphogenesis. In contrast, androgen-producing cells are unaffected in germ-cell-deficient medaka of either sex. In addition, a single tube-like gonad that expresses male-specific genes is formed in these mutants irrespective of the genetic sex. Significantly, each of these mutant phenotypes occurs in a somatic cell-autonomous manner, suggesting that gonadal somatic cells are predisposed toward male development in the absence of germ cells. This highlights the importance of germ cells in the sexual dimorphism of the gonads.
Volume 104(43)
Pages 16958-63
Published 2007-10-23
DOI 10.1073/pnas.0609932104
PII 0609932104
PMID 17940041
PMC PMC2040408
MeSH Androgens / biosynthesis Animals Cell Lineage Female Gene Expression Regulation, Developmental Germ Cells / cytology* Germ Cells / ultrastructure Male Molecular Sequence Data Oryzias / genetics Oryzias / physiology* Ovary / cytology* Ovary / embryology Ovary / ultrastructure Receptors, CXCR4 / metabolism Sex Characteristics* Sex Differentiation Testis / cytology* Testis / embryology Testis / ultrastructure
IF 9.58
Times Cited 104
Medaka inbred cab strain