This project aims to study how the two main hormones, FSH and testosterone, control the development and production of sperm throughout adult life. In previous NHMRC-supported research we were the first to overturn the long-standing belief that FSH was vital to the start of sperm production in all warm-blooded animals. This insight was achieved from experiments using a genetically modified strain of mouse. We used this mouse strain to develop a new experimental paradigm to provide unique insight ....This project aims to study how the two main hormones, FSH and testosterone, control the development and production of sperm throughout adult life. In previous NHMRC-supported research we were the first to overturn the long-standing belief that FSH was vital to the start of sperm production in all warm-blooded animals. This insight was achieved from experiments using a genetically modified strain of mouse. We used this mouse strain to develop a new experimental paradigm to provide unique insight into how hormones start up and support sperm production. In this present proposal we wish to take this research further. Although we have shown that FSH is not vital to the startup or continuing of sperm production, we believe it still does have an important role in causing the growth of a large enough population of Sertoli cells of the testis. These highly specialised cells have the unique job to support, nourish and coordinate the production of sperm. Sertoli cells are known to be the only target in the body for FSH and so that FSH must act upon them exclusively. We believe this occurs almost solely during early life - starting before birth and into early infancy - well before adult life when sperm are produced for the first time. In this way these processes being studied determine the size of mature testis. Our new approaches to studying the question of how the two main hormones control sperm production involve developing new types of genetically modified mice which have extra and exclusive FSH activity as well as some new research methods to be applied to understanding how FSH acts on the Sertoli cell using techniques derived from gene therapy and from cell transplantation. This research has the possibility to uncover new causes of previously unexplained male infertility (the majority having no known cause so far), to help develop better hormonal male contraceptives, and to quetion the need for expensive treatments for some infertile men.Read moreRead less