Sertoli cell transfer restores sperm production in infe...( PHILADELPHIA -- Scientists at the Unive...)

The research, reported on the Web site of the journal Biology of Reproduction, may give scientists a better understanding of how Sertoli cells -- which surround spermatogenic stem cells -- nourish sperm production and the survival of stem cells.

"Spermatogenesis is a highly organized process, requiring just the right environment, or 'niche,' around the germ line stem cells," said Ralph L. Brinster, professor of reproductive physiology at Penn. "The Sertoli cells are essential to this environment, and it appears that by replacing them, we can essentially reconstruct the niche in which sperm development takes place."

Much of the volume of a mammalian testis consists of tightly coiled seminiferous tubules that hold mature sperm. Sperm development also occurs within these tubules, which are home to spermatogenic stem cells, the seeds from which spermatogenesis arises. Seminiferous tubules are lined with Sertoli cells, which are thought to nurture sperm cells as they develop and facilitate their eventual passage out of the testis.

Brinster and colleagues worked with Steel mutant mice, which are congenitally infertile due to a Sertoli cell defect. Before inserting healthy Sertoli cells, the researchers treated the mice's testes with busulfan and cadmium to remove any defective germ cells and Sertoli cells. The seminiferous tubules remained, likely providing the structural support needed to completely reconstitute spermatogenesis from donor cells.

The Brinster group's technique for transplanting Sertoli cells will likely allow scientists to study stem cells' specialized environment in a way that has not been possible before. Currently, the best-studied stem cells are those that generate bl
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Contact: Steve Bradt
bradt@pobox.upenn.edu
215-573-6604
University of Pennsylvania
15-Nov-2002