Mechanisms Of Gonadal Differentiation Research Articles

Mechanisms of gonadal differentiation in vertebrates. Preface and introduction.

The topic of the present issue of Differentiation — ‘Mechanisms of gonadal (primary sex) differentiation in vertebrates’ — addresses one of man’s oldest questions, that of the origin of male and female. Before the study of natural science this question was answered in religious metaphor and philosophical speculation. It is remarkable how close some of these explanations come to the actual situation.

Structural aspects of gonadal differentiation in mammals and birds.

The task of this review is to discuss the morphogenetic mechanisms of gonadal differentiation. The structural events which result in the formation of the genital ridge blastema in the sexually differentiated male or female organ, or in the creation of an ovarian cortex, are difficult to ascertain. Accordingly, several concepts have been elaborated in the past that try to explain gonadal differentiation more or less extensively. Most of these concepts focus on the main aspect of gonadal development: the process of sexual differentiation. Among the different concepts are those conceived from a primarily morphological aspect; others present an entirely functional view.

Mechanisms of gonadal differentiation.

Sex differentiation is the result of the translation of genetic sex into gonadal sex. Without recognizable masculinizing signals the embryonic gonad will undergo ovarian differentiation. The main determinant of gonadal differentiation appears to be the presence or absence of a cell surface antigen, called H-Y antigen. The regulation of H-Y antigen expression is complex and involves the interaction between regulatory sites on the Y chromosome, the X chromosome, and possibly the autosomes.