Gonadal ridge
（重定向自Genital ridge）
In embryology, the gonadal ridge (or genital ridge) is the precursor to the gonads. The gonadal ridge initially consists mainly of mesenchyme and cells of underlying mesonephric origin. Once oogonia enter this area they attempt to associate with these somatic cells. Development proceeds and the oogonia become fully surrounded by a layer of cells (pre-granulosa cells).