Relatively little is known regarding the signals that regulate the proliferation and sex-specific development of germ cells during mammalian fetal gonad differentiation. Members of the bone morphogenetic protein (BMP) family have been identified as key regulators of germ cells in the Drosophila gonad. Here we show that in mice Bmp7 is expressed in gonads of both sexes and is required for germ c...

like) exhibit a pleiotropic phenotype including abnormalities of cardiac, skeletal and limb development, in addition to renal agenesis. Here we report abnormalities of gonad development in homozygous mutants. From early stages, Vcc/Vcc embryos contain gonads longer than controls and by 13.5 dpc this increased length is evidenced by an increase in the number of testis cords. The gene mutated in ...

The aim of this study was to test the ability of magnetic resonance imaging (MRI) technique to characterize gonad development and to determine the sex of live Pacific oysters through their shells. A preliminary nuclear magnetic resonance (NMR) relaxometry study was conducted to characterize T1 and T2 NMR relaxation parameters for the main oyster organs. This showed that T1-weighted MRI sequence...

What is sex determination? Sex determination is the mechanism by which sexual organisms direct gonad development towards distinct but reproductively compatible outcomes. Molecular signaling cascades in the developing gonad provide instructions to the tissue to develop as male or female (or in some cases hermaphrodite), and these signals can be initiated in different ways. Sex can be determined ...

In most animals, the gonads develop symmetrically, but most birds develop only a left ovary. A possible role for estrogen in this asymmetric ovarian development has been proposed in the chick, but the mechanism underlying this process is largely unknown. Here, we identify the molecular mechanism responsible for this ovarian asymmetry. Asymmetric PITX2 expression in the left presumptive gonad le...

In mammals, the primary step in male sex determination is the initiation of testis development which depends on the expression of the Y-linked testis determining gene, Sry. The mechanisms by which Sry controls this process are unknown. Studies showed that cell migration from the adjacent mesonephros only occurs into XY gonads; however, it was not known whether this effect depended on Sry, anoth...

like) exhibit a pleiotropic phenotype including abnormalities of cardiac, skeletal and limb development, in addition to renal agenesis. Here we report abnormalities of gonad development in homozygous mutants. From early stages, Vcc/Vcc embryos contain gonads longer than controls and by 13.5 dpc this increased length is evidenced by an increase in the number of testis cords. The gene mutated in ...

The Caenorhabditis elegans gene lin-9 functions in an Rb-related pathway that acts antagonistically to a receptor tyrosine kinase/Ras signal transduction pathway controlling vulval induction. We show that lin-9 is also required for the development of the sheath cells in the hermaphrodite gonad and for the development of the male spicule, rays and gonad. lin-9 is transcribed as two alternatively...

like) exhibit a pleiotropic phenotype including abnormalities of cardiac, skeletal and limb development, in addition to renal agenesis. Here we report abnormalities of gonad development in homozygous mutants. From early stages, Vcc/Vcc embryos contain gonads longer than controls and by 13.5 dpc this increased length is evidenced by an increase in the number of testis cords. The gene mutated in ...

Human sex determination is a fascinating topic, particularly at the level of molecular genetics, as it represents an excellent paradigm for mammalian organ development. Recent progress has seen the addition of several new pieces to this developmental jigsaw puzzle. In mammals, the Y chromosome is male determining, and encodes a gene referred to as TDF (testis-determining factor), which induces ...