Changes in Sperm Surface Membrane and Luminal Protein Fluid Content during Epididymal Transit in the Boar1

Abstract

The surface membrane protein of boar sperm and the proteins in the fluid surrounding the gametes were analyzed during epididymal transit. The present study demonstrated that sequential dramatic changes occur in protein composition of the sperm membrane and epididymal fluid during epididymal transit. The maturation process of the boar sperm surface was characterized by a complex sequential evolution of the composition and orientation of macromolecules in the sperm membrane. Epididymal maturation resulted in the progressive disappearance of most of the surface testicular compounds, which were either renewed or masked by new permanent or transient low molecular weight polypeptides on the boar sperm surface membrane. In the fluid surrounding the spermatozoa, composition of the luminal proteins was altered throughout the epididymal transit and several new compounds were characterized. Very few proteins were correlated either with blood plasma or sperm surface compounds.

Characterization of the porcine seminal plasma proteome comparing ejaculate portions

“…The absence of quantitative differences in SP-protein expression between P1 and P2 may be understandable, as P1 and P2 together comprise the first naturally occurring ejaculate fraction (SRF), whose SP has a common origin, albeit having amount differences [5]. to some specific sperm functionalities, as membrane stability and permeability (GLB1L3, [46]; ARSA, [47]), capacitation (HEXB, [48]), acrosome reaction (GP2, [49]), fertilizing ability (LCN-5, [50]) or sperm-zone pellucid binding (ARSA, [51]). …”

Lectin-Binding Characteristics and Capacitation of Canine Epididymal Spermatozoa

“…GPs that coat the sperm surface are acquired or lost during sperm transit through the epididymis, and the characteristics of the GPs on the surface of the plasma membrane of mammalian sperm vary with the species [6,9,20,23]. Some GPs coating the sperm surface are derived from epididymal fluid [5,15,17,23].…”

“…These findings indicate that both DBA-and SBA-lectin-binding GPs, which are composed of methyl-2-acetamide-2-deoxy-D-galactose and N-acetyl-D-galactosamine, respectively, are removed from the surface of the head of canine sperm during sperm transit from the corpus epididymides to the cauda epididymides and by washing the corpus epididymal sperm. In the ram [29] and the pig [4,6], GP content on the sperm surface decreases during sperm transit through the epididymis, and the decrease is thought to be associated with sperm maturation [6,29]. The GPs coating the surface of boar epididymal sperm are gradually lost due to the hydrolytic effects of enzymes secreted by the epididymal epithelium [6].…”

“…64 (7): [543][544][545][546][547][548][549] 2002 It is well-known that the mammalian sperm plasma membrane surface is coated with various glycoproteins (GPs) [8,9,20,21,25]. Although some GPs are already present on the surface of immature sperm in the seminiferous tubules of the testis [18,19], the surface of the sperm becomes covered with a wide variety of GPs secreted by the epididymal epithelium during sperm transit through the epididymis [5,6,17,23]. Sperm surface GPs are thought to induce sperm maturation and fertilizing capacity [10,20] in the epididymal duct, and techniques utilizing fluorescein-isothiocyanate (FITC)-labeled lectins have revealed that the sperm surface GPs are biochemically modified during sperm transit through the epididymis and that there are species-dependent differences in sperm surface GPs [1,5,6,17,20,23].…”

“…Although some GPs are already present on the surface of immature sperm in the seminiferous tubules of the testis [18,19], the surface of the sperm becomes covered with a wide variety of GPs secreted by the epididymal epithelium during sperm transit through the epididymis [5,6,17,23]. Sperm surface GPs are thought to induce sperm maturation and fertilizing capacity [10,20] in the epididymal duct, and techniques utilizing fluorescein-isothiocyanate (FITC)-labeled lectins have revealed that the sperm surface GPs are biochemically modified during sperm transit through the epididymis and that there are species-dependent differences in sperm surface GPs [1,5,6,17,20,23]. Some of the GPs on the surface of epididymal sperm have been suspected of acting as decapacitation factors (DFs) [16,21], and while sperm fertilizing capacity is induced by removing DFs from the sperm surface [7,16], there have been few reports on the lectin-binding characteristic of the GP on the surface of canine epididymal sperm [1].…”