Biology of Reproduction, Vol 29, 257-270, Copyright © 1983 by Society for the Study of Reproduction

ARTICLES

Identification of stage-specific proteins synthesized by rat seminiferous tubules

WW Wright, M Parvinen, NA Musto, GL Gunsalus, DM Phillips, JP Mather and CW Bardin

Experiments were conducted to determine how the cycle of the seminiferous epithelium influenced synthesis and secretion of proteins by seminiferous tubules. Tubular segments were treated with collagenase and then cultured with [35S]methionine. These myoid cell-depleted tubules isolated from different stages of the epithelial cycle exhibited, at Stages VI and XII, two distinct peaks of secretion of total radiolabeled proteins. Two-dimensional gel electrophoresis indicated that the patterns of secreted proteins from these two stages were remarkably different, while those from other stages were intermediate between those at the peaks. At least 15 proteins were secreted cyclically, many of them previously unrecognized products of the seminiferous epithelium. One product, designated Cyclic Protein-2 (CP-2), exhibited a pronounced cycle of secretion, its peak at Stage VI being 30-fold greater than at its nadir at Stages XII-XIV. Further investigation indicated that CP-2 did not appear to originate from myoid cells or dispersed germ cells but could be recovered from Sertoli cell-enriched cultures prepared from Stage VI tubules. Protein secretion by tubular segments was also characterized by immunoprecipitation with two polyspecific antisera directed against Sertoli cell products. Five secretory proteins were identified which had cycles different from one another and from CP-2. In contrast to secreted products, the synthesis of most cellular proteins by tubular segments remained relatively constant throughout the cycle. It is concluded: 1) segments of the seminiferous epithelium secrete proteins into the culture medium which are distinct from cellular proteins; 2) the synthesis of many of these proteins varies with the epithelial cycle; and 3) several of the secreted proteins are of Sertoli cell origin, including a newly identified protein, CP-2. This indicates that the morphology and the protein synthetic capacity of the seminiferous epithelium are coordinated over space and time.

This article has been cited by other articles:

				M. G. Yefimova, A. Sow, I. Fontaine, V. Guilleminot, N. Martinat, P. Crepieux, S. Canepa, M.-C. Maurel, S. Fouchecourt, E. Reiter, et al. Dimeric Transferrin Inhibits Phagocytosis of Residual Bodies by Testicular Rat Sertoli Cells Biol Reprod, April 1, 2008; 78(4): 697 - 704. [Abstract] [Full Text] [PDF]

				K. P. Griffin, D. T. Ward, W. Liu, G. Stewart, I. D. Morris, and C. P. Smith Differential expression of divalent metal transporter DMT1 (Slc11a2) in the spermatogenic epithelium of the developing and adult rat testis Am J Physiol Cell Physiol, January 1, 2005; 288(1): C176 - C184. [Abstract] [Full Text] [PDF]

				C. Gaudreault, M. El Alfy, C. Legare, and R. Sullivan Expression of the Hamster Sperm Protein P26h During Spermatogenesis Biol Reprod, July 1, 2001; 65(1): 79 - 86. [Abstract] [Full Text] [PDF]

				R. R. Fortna, H. A. Watson, and S. E. Nyquist Glycosyl Phosphatidylinositol-Anchored Ceruloplasmin Is Expressed by Rat Sertoli Cells and Is Concentrated in Detergent-Insoluble Membrane Fractions Biol Reprod, October 1, 1999; 61(4): 1042 - 1049. [Abstract] [Full Text]