TESTICULAR SPERMATOGENESIS, MORPHOGENESIS, AND GENE EXPRESSION
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(485) SERTOLI CELLS REVEAL STRUCTURAL CHANGES REFLECTING WATER RETENTION IN ADULT FORKO MICE.
Badran, Haitham1, Grover, Amit1, Sairam, Ram2, Hermo, Louis1, 1 Department of Anatomy and Cell Biology, Montreal, CA2 Molecular Reproduction Research Lab, Montreal, CA
ABSTRACT- The follicle-stimulating hormone receptor (FSH-R) has been localized to Sertoli cells of the testis; however its functional role has not been fully elucidated. In the present study, mice deficient in the FSH-R (FORKO) were examined at 3 and 6 months of age and compared with their wild-type counterparts. The testes of all animals were fixed by cardiac perfusion with 5% glutaraldehyde and embedded in Epon to assess morphological changes at the light (LM) and electron (EM) microscopic level. The testes were also fixed in Bouin's fixative and embedded in paraffin for LM immunocytochemistry. In the LM, the seminiferous epithelium of many tubules of FORKO mice was grossly vacuolated, as evidenced by large irregularly shaped spaces separated by anastomotic cords of germ cells or enveloping clusters of late spermatids. Such spaces spanned the entire width of the epithelium or were seen adluminally. In addition, these spaces either partially or completely enveloped each tubule. Such a phenotype was not evident in wild-type mice. In the EM, these spaces were attributed to a swelling of the cytoplasm of Sertoli cells, which lacked a homogeneous ground substance and appeared to be engorged with fluid. Internal organelles such as mitochondria and lysosomes and the Golgi apparatus appeared to be floating chaotically within, while ER elements and microtubules were not readily apparent. The processes of Sertoli cells encapsulating the heads of late spermatids, normally thin, were greatly swollen in FORKO mice giving the overall impression that the spermatid heads were floating in large fluid filled spaces. However, the Sertoli cell nuclei appeared normal, as did the extensive Sertoli-Sertoli blood testis barrier, and ectoplasmic specializations located between Sertoli cells and late spermatids. In addition, LM immunostaining with an anti-prosaposin antibody that stains Sertoli cells revealed that the overall shape of some Sertoli cells of the seminiferous epithelium appeared to be altered in FORKO mice as compared to wild-type mice. Taken together, the data suggest that FSH-R signaling regulates the movement of water through the Sertoli cell cytoplasm, and that in its absence, there is a disruption of Sertoli cell structure that could have serious consequences on their functions and support of germ cells. (Supported by CIHR).
KEY WORDS: Testis, Sertoli, FSH-R, Water