Differentiation and development of the male

Area of Science:

• Reproductive biology
• Developmental biology
• Endocrinology

Background:

• Male sexual differentiation is a complex process that occurs against a background of neutral or female development.
• A normally functioning testis is essential for imposing male characteristics during development.
• Testicular function, once established, is critical for male sexual maturation.

Purpose of the Study:

• To propose the concept of 'ontogenic rhythms' to describe critical periods of testicular activity.
• To elucidate the role of testicular function in male differentiation and sexual maturation.

Main Methods:

• Review of existing literature on male sexual differentiation and testicular development.
• Conceptual framework development for 'ontogenic rhythms'.

Main Results:

• Male differentiation involves the suspension of basic female development and the imposition of male features.
• Three distinct periods of maximal testicular activity ('ontogenic rhythms') are identified: fetal, neonatal, and adult.
• Maintenance of normal testicular function is crucial for successful male sexual differentiation and maturation.

Conclusions:

• Normal testicular function, characterized by specific 'ontogenic rhythms', is fundamental for male sexual development.
• Understanding these rhythms provides insight into the temporal regulation of male sexual differentiation and adult sexual activity.