Journal of Cell Science, Vol 96, Issue 4 745-756, Copyright © 1990 by Company of Biologists

JOURNAL ARTICLES

Temporal expression, polar distribution and transition of an epitope domain in the perinuclear theca during mouse spermatogenesis

AR Bellve, R Chandrika and A Barth
Department of Anatomy and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032.

A novel domain of epitopes is expressed by a family of high-Mr proteins at the anterior pole of the germ cell nucleus during spermiogenesis, and later by two low-Mr proteins at the anterior and posterior poles of the nucleus during sperm maturation in the epididymis. Initially, monoclonal antibodies (mAbs) PNT-1 (IgG2b) and PNT-2 (IgG2a) bound to antigens present in a cap-like configuration at the apical pole of the spermatid nucleus at step 5 of spermiogenesis. The distribution of epitopes on the nucleus expanded posteriorly until, in testicular sperm they covered the anterior pole down to the distal limits of the subacrosomal perforatorium. By contrast, sperm from the epididymis and vas deferens bound both mAbs in two distinct regions on the nucleus, one on the dorsal margin of the anterior pole, and the other in a ventral zone at the posterior pole. On SDS-PAGE and isoelectric focusing (IEF) immunoblots, both mAbs bound three major proteins with Mr of approximately 80,000, 77,000 and 75,000 from spermatids and testicular sperm, and proteins of Mr 50,000 and 48,000 in epididymal and vas deferens sperm. Both the high- and low-Mr protein families were recovered in germ cell nuclear/perinuclear matrices. Their mobilities on SDS-PAGE were not altered by exo- or endoglycosidases or by aminoethylation in denaturing conditions. mAb PNT-1 bound to the sperm proteins with a Ka of 3.53 x 10(12) M-1 and mAb PNT-2 with a Ka of 2.08 x 10(12) M-1. From competition binding data, mAbs PNT-1 to -10 appeared to recognize six adjacent or overlapping epitopes on the same proteins. These data suggest the high-Mr proteins, the thecins, present at the anterior pole of haploid germ cells are processed at the onset of sperm maturation to yield two low-Mr proteins that then occupy two distinct domains at the anterior and posterior poles of the nucleus.

This article has been cited by other articles:

				I. Martianov, S. Brancorsini, R. Catena, A. Gansmuller, N. Kotaja, M. Parvinen, P. Sassone-Corsi, and I. Davidson Polar nuclear localization of H1T2, a histone H1 variant, required for spermatid elongation and DNA condensation during spermiogenesis PNAS, February 22, 2005; 102(8): 2808 - 2813. [Abstract] [Full Text] [PDF]

				C. Lécuyer, J.-L. Dacheux, E. Hermand, E. Mazeman, J. Rousseaux, and R. Rousseaux-Prévost Actin-Binding Properties and Colocalization with Actin During Spermiogenesis of Mammalian Sperm Calicin Biol Reprod, December 1, 2000; 63(6): 1801 - 1810. [Abstract] [Full Text]

				G Herrada and D. Wolgemuth The mouse transcription factor Stat4 is expressed in haploid male germ cells and is present in the perinuclear theca of spermatozoa J. Cell Sci., January 7, 1997; 110(14): 1543 - 1553. [Abstract] [PDF]

				E Sonnenberg-Riethmacher, B Walter, D Riethmacher, S Godecke, and C Birchmeier The c-ros tyrosine kinase receptor controls regionalization and differentiation of epithelial cells in the epididymis. Genes & Dev., May 15, 1996; 10(10): 1184 - 1193. [Abstract] [PDF]