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Group leader:
Professor Rob McLachlan
 Short CV [pdf]
Our Group is seeking to understand how hormones control the development of sperm, from immature germ cells into highly specialised spermatozoa. Knowledge of how hormones act in the testis, and how the development of sperm is regulated will allow us to better understand how to control this process for contraceptive purposes, as well as develop treatments for infertility. Aspects of sperm production currently being investigated include:
1. Spermatogonia (pre-cursor germ cells)
The proliferation of one spermatogonium results in the production of 256 sperm and thus these cells are a prime target for contraception. We have recently found that the reproductive hormone, follicle-stimulating hormone (FSH) is the key hormone responsible for spermatogonial division. We are currently investigating other factors which control the proliferation of these cells.
2. Spermatid development
We have shown that one possible target for contraception is the adhesive mechanism that anchors developing spermatids to Sertoli cells. We are now studying the architecture of the junction between these cells and the hormones and factors involved in its regulation. In particular, we are developing cell culture models to study the cellular interactions and adhesive junctions involved.
3. Spermatid release
We have found that when a contraceptive hormone is administered, one of the first defects in sperm production is that the normal release of mature sperm from the Sertoli cell is prevented. We are now studying the biochemical mechanisms involved in sperm release, and the hormonal regulation of this process in humans.
4. 5 alpha-reductase enzyme
This enzyme converts the male hormone, testosterone, into a more potent hormone, dihydrotestosterone. There is evidence to suggest that higher levels of 5a-reductase may be one reason why some men do not respond as effectively to contraceptives as others, because their higher 5a-reductase activity may allow more active androgens to accumulate in the testis. We have recently found that FSH and testosterone regulate this enzyme. These findings have important implications for how the levels of 5a-reductase, and thus more active androgens, in the testis are produced.
Relevance of our research to the human
A strength of our research is our connections with clinical research. Together with the Clinical Research in Reproductive Endocrinology Group (led by Assoc Prof Rob McLachlan) we are able to use basic research in cells and animal models to understand the factors that regulate various processes in male reproduction. We then investigate these processes in biopsy tissue taken from men, in order to apply our findings to the human. The application of basic research to clinical studies in male reproduction is expanded upon in the following section.
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MALE REPRODUCTIVE