Human Reproduction, Vol. 19, No. 1, 139-146,
January 2004
© 2004 European Society of Human Reproduction and Embryology
Human sperm subpopulations: relationship between functional quality and protein tyrosine phosphorylation
1 Laboratorio de Estudios en Reproducción (LER), Buenos Aires, Argentina, 2 CONRAD Program, Department of Obstetrics and Gynecology, The Jones Institute for Reproductive Medicine, Eastern Virginia Medical School, 601 Colley Ave, Norfolk, VA 23507, USA and 3 Instituto de Biología y Medicina Experimental, CONICET-UBA, Buenos Aires, Argentina
4 To whom correspondence should be addressed. e-mail: DoncelGF{at}evms.edu
BACKGROUND: Human semen is composed of a heterogeneous population of sperm with varying degrees of structural and functional differentiation and normality, which result in subpopulations of different quality. METHODS: Using a discontinuous Percoll gradient, we separated three subsets of sperm [(45%; L45), (65%; L65) and (90%; L90) fractions] from normozoospermic human semen samples from healthy donors and proceeded to characterize their morphology, motility and hyperactivation, as well as their ability to undergo tyrosine phosphorylation under capacitating conditions. RESULTS: As expected, sperm isolated from the lowest density layer (L45) showed the poorest quality, displaying the smallest percentage of morphologically normal and motile sperm. During a capacitating incubation, this subset of cells also showed deficient capacity to undergo hyperactivation and protein tyrosine phosphorylation. Conversely, sperm isolated from the other layers (L65 and L90) showed a time-dependent progressive increment in tyrosine phosphorylation, establishing statistically significant differences with sperm from L45. The tyrosine phosphorylation deficiency of L45 sperm could be overcome when sperm from that fraction were stimulated with activators of the cAMP-dependent kinase (PKA) pathway (dbcAMP + pentoxifylline), pointing to the sperm’s plasma membrane as the main site of such deficiency. CONCLUSIONS: Poor quality sperm isolated from a Percoll gradient display an intrinsic tyrosine phosphorylation deficiency, possibly caused by a plasma membrane defect, which is associated with their inability to undergo normal capacitation and, ultimately, acquire optimal fertilizing potential.
Key words: capacitation/human sperm/hyperactivation/Percoll gradient/protein tyrosine phosphorylation
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  M. G. Buffone, S. V. Verstraeten, J. C. Calamera, and G. F. Doncel High Cholesterol Content and Decreased Membrane Fluidity in Human Spermatozoa Are Associated With Protein Tyrosine Phosphorylation and Functional Deficiencies J Androl, September 1, 2009; 30(5): 552 - 558. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. A. Mitchell, B. Nixon, M. A. Baker, and R. J. Aitken Investigation of the role of SRC in capacitation-associated tyrosine phosphorylation of human spermatozoa Mol. Hum. Reprod., April 1, 2008; 14(4): 235 - 243. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. E. Edwards, M. G. Buffone, G. R. Knee, M. Rossato, G. Bonanni, S. Masiero, S. Ferasin, G. L. Gerton, S. B. Moss, and C. J. Williams Effects of Extracellular Adenosine 5'-Triphosphate on Human Sperm Motility Reproductive Sciences, October 1, 2007; 14(7): 655 - 666. [Abstract] [PDF]
|
|
|
|
 |
|
 I. Gilbert, N. Bissonnette, G. Boissonneault, M. Vallee, and C. Robert A molecular analysis of the population of mRNA in bovine spermatozoa Reproduction, June 1, 2007; 133(6): 1073 - 1086. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. G Buffone, J. C Calamera, S. V Verstraeten, and G. F Doncel Capacitation-associated protein tyrosine phosphorylation and membrane fluidity changes are impaired in the spermatozoa of asthenozoospermic patients Reproduction, June 1, 2005; 129(6): 697 - 705. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Martinez-Pastor, V. Garcia-Macias, M. Alvarez, P. Herraez, L. Anel, and P. de Paz Sperm Subpopulations in Iberian Red Deer Epididymal Sperm and Their Changes Through the Cryopreservation Process Biol Reprod, February 1, 2005; 72(2): 316 - 327. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. V. Harper, C. L. R. Barratt, and S. J. Publicover Stimulation of Human Spermatozoa with Progesterone Gradients to Simulate Approach to the Oocyte: INDUCTION OF [Ca2+]i OSCILLATIONS AND CYCLICAL TRANSITIONS IN FLAGELLAR BEATING J. Biol. Chem., October 29, 2004; 279(44): 46315 - 46325. [Abstract] [Full Text] [PDF]
|
|