Related Experiment Video
Updated: May 27, 2026

Stable Isotope In-Vivo Labeling for Mass-Spectrometry Identification of Paternal Metabolites Transferred from Sperm to Oocyte During Fertilization
Published on: June 17, 2025
Estrogens: new players in spermatogenesis.
Serge Carreau1, Hélène Bouraima-Lelong, Christelle Delalande
1University of Caen Basse-Normandie, Esplanade de la Paix-14032, CAEN Cedex, France. serge.carreau@unicaen.fr
Estrogen synthesis occurs in rat germ cells, which also possess estrogen receptors and respond to estrogens. These findings highlight estrogens' crucial role in male reproductive functions and sperm development.
Area of Science:
- Reproductive biology
- Endocrinology
- Cell biology
Background:
- Aromatase, an enzyme irreversibly converting androgens to estrogens, is found in the mammalian testis' smooth endoplasmic reticulum.
- In rodents, most testicular cells, excluding myoid cells, exhibit aromatase activity.
Purpose of the Study:
- To investigate the presence and function of aromatase in adult rat germ cells.
- To determine the role of estrogens in male reproduction, particularly in spermatogenesis.
Main Methods:
- Demonstration of functional aromatase (transcript, protein, biological activity) in pachytene spermatocytes and round spermatids.
- Measurement of estrogen output from isolated germ cells.
- Localization studies of estrogen receptors in testicular somatic and germ cells.
- Investigation of rapid estrogen membrane effects via G protein-coupled receptor (GPER) in germ cells.
Main Results:
- Functional aromatase, estrogen production, and estrogen receptors were confirmed in adult rat germ cells.
- Germ cells produced estrogen levels comparable to Leydig cells.
- Estrogen receptors were found in both testicular somatic and germ cells.
- Estrogens exert rapid membrane effects in rat germ cells through GPER.
Conclusions:
- Estrogens are synthesized and utilized within testicular germ cells.
- Estrogens play a critical role in male reproductive functions, specifically in the development of spermatozoa.
Related Concept Videos
Spermatogenesis
Spermatogenesis
The process of spermatogenesis can be divided into mitosis, meiosis, and spermiogenesis. During mitosis, the spermatogonia or stem cells divide to produce two identical daughter cells, type A and B spermatogonia. Type-A...
Gonadal and Placental Hormones
In males, testosterone is the primary gonadal androgen. It plays a central role in the maturation of male reproductive organs — the penis and testes. Additionally, testosterone is instrumental in the development of secondary sexual characteristics — a deep voice as well as facial and pubic hair growth — and...
Oogenesis
Oogenesis
Each primary oocyte is surrounded by a layer of pre-granulosa cells, forming what is known...
Fertilization

