Genital ridge
The genital ridge is the conditioning of the gonads (gonadal) at an embryo . It is a bilateral, longitudinal thickening of the epithelium of the coeloma and the underlying mesenchyme , which forms in the 4th week of development - on the 26th day of germ development - and from which the gonads subsequently develop.
The genital strips are thus on the body rear wall between the rear mesentery and also on both sides applied Urnierenleisten . In most vertebrates , only the middle section of this appendix forms the gonad, the anterior and posterior parts become the goneal ligaments .
In the early stages of development it is not yet possible to distinguish between male and female genital development: the sex of most animals is genetically determined. Germ cells are not yet present in the genital ridge. These migrate as primordial germ cells from the 5th week of development from the wall of the yolk sac over the mesentery of the rectum towards the genital ridge and reach it in the 6th week of development.
literature
- Bertram Schnorr, Monika Kressin: Embryology of Pets. 5th edition. Enke, Stuttgart 2006, ISBN 3-8304-1061-1 .