Analysis of lipid and protein components of ejaculated bull sperm surface and seminal plasma

ABSTRACT Background Wide variation in fertility rates is observed when using frozen bull semen, even when the bulls have met quality standards for semen production. Therefore, a simple and reliable test to assess the freezing potential of bull semen based on the analysis of fresh semen or blood would be of great value. Attention is now turning to assessment of seminal plasma components such as proteins and elements. In the present study, the concentrations of macro- and microelements in fresh bull semen plasma and in serum and their correlation with quality characteristics of fresh semen and with semen quality after freezing and thawing were determined. Ejaculates were collected from 30 mature bulls, and semen volume, concentration, sperm motility, morphology, tail membrane integrity, plasma membrane permeability and DNA fragmentation were determined on the day of collection and after freezing and thawing. The concentrations of macroelements (Na, Mg, K and Ca) and microelements (Cu, Fe, Zn and Se) were determined in the seminal plasma and serum. The semen samples were classified into satisfactory and unsatisfactory groups according to the fresh semen quality. Results Zinc and Se levels measured in serum were associated with almost all fresh and frozen-thawed semen quality characteristics, while Fe levels were associated only with acrosomal defects in fresh semen. Zinc and Fe levels in fresh seminal plasma were associated with various quality characteristics of fresh and frozen-thawed semen, while Se level in fresh seminal plasma was not associated with any of the semen quality characteristics. Conclusions Microelements were shown to be useful as biomarkers involved in the analysis of bull sperm quality and could be used as an additional tool to predict bull semen quality after freezing and thawing. Our results confirm that the analysis of Zn and Se levels in serum and Zn, Cu and Fe levels in fresh seminal plasma can provide information to discriminate between bull semen samples with spermatozoa with high or low cryotolerance.

Download Full-text

Heparin- and Zn2+-binding proteins from boar seminal plasma.

Acta Biochimica Polonica ◽

10.18388/abp.1999_4116 ◽

1999 ◽

Vol 46 (4) ◽

pp. 935-939 ◽

Cited By ~ 5

Author(s):

D Hołody ◽

J Strzezek

Keyword(s):

Amino Acid ◽

Affinity Chromatography ◽

Molecular Mass ◽

Seminal Plasma ◽

Binding Proteins ◽

Reproductive Tract ◽

Female Reproductive Tract ◽

Heparin Binding ◽

Sds Page ◽

Protein Components

Low molecular mass, heparin-binding proteins from seminal plasma play an important role in gametes interaction whereas plasmatic Zn2+-binding proteins stabilize chromatin and plasmalemma structures and protect spermatozoa in the female reproductive tract. By means of affinity chromatography the heparin- and Zn2+-binding proteins were isolated from boar seminal plasma and both preparations were analyzed by reverse HPLC. Most of the proteins bound to heparine and Zn2+-ions were classified as spermadhesins. Three fractions binding exclusively Zn2+ were isolated. They differ in amino-acid composition, content of glucosamine and content of protein components revealed by SDS/PAGE.

Download Full-text

The role of galectin-3 in spermatozoa-zona pellucida binding and its association with fertilization in vitro

MHR Basic science of reproductive medicine ◽

10.1093/molehr/gaz030 ◽

2019 ◽

Vol 25 (8) ◽

pp. 458-470 ◽

Cited By ~ 2

Author(s):

Si Mei ◽

Panyu Chen ◽

Cheuk-Lun Lee ◽

Weie Zhao ◽

Ying Wang ◽

...

Keyword(s):

Seminal Plasma ◽

Zona Pellucida ◽

Binding Capacity ◽

Fertilization Rate ◽

Clinical Samples ◽

Fertilization In Vitro ◽

Human Seminal Plasma ◽

Sperm Surface ◽

Galectin 3

AbstractHuman spermatozoa can fertilize an oocyte only after post-testicular maturation and capacitation. These processes involve dynamic modification and reorganization of the sperm plasma membrane, which allow them to bind to the zona pellucida (ZP) of the oocyte. Defective sperm-ZP binding is one of the major causes of male subfertility. Galectin-3 is a secretory lectin in human seminal plasma well known for its action on cell adhesion. The aim of this study was to determine the role of galectin-3 in spermatozoa-ZP interaction and its association with fertilization rate in clinical assisted reproduction. Our studies revealed that the acrosomal region of ejaculated and capacitated spermatozoa possess strong galectin-3 immunoreactivity, which is much stronger than that of epididymal spermatozoa. Expression of galectin-3 can also be detected on seminal plasma-derived extracellular vesicles (EVs) and can be transferred to the sperm surface. Blocking of sperm surface galectin-3 function by antibody or carbohydrate substrate reduced the ZP-binding capacity of spermatozoa. Purified galectin-3 is capable of binding to ZP, indicating that galectin-3 may serve as a cross-linking bridge between ZP glycans and sperm surface glycoproteins. Galectin-3 levels in seminal plasma-derived EVs were positively associated with fertilization rates. These results suggest that galectin-3 in EVs is transferred to the sperm surface during post-testicular maturation and plays a crucial role in spermatozoa-ZP binding after capacitation. Reduced galectin-3 expression in seminal plasma-derived EVs may be a cause behind a low fertilization rate. Further studies with more clinical samples are required to confirm the relationship between galectin-3 levels and IVF outcomes.

Download Full-text

The Ubiquitin-Proteasome System Does Not Regulate the Degradation of Porcine β-Microseminoprotein during Sperm Capacitation

International Journal of Molecular Sciences ◽

10.3390/ijms21114151 ◽

2020 ◽

Vol 21 (11) ◽

pp. 4151

Author(s):

Lucie Tumova ◽

Michal Zigo ◽

Peter Sutovsky ◽

Marketa Sedmikova ◽

Pavla Postlerova

Keyword(s):

Seminal Plasma ◽

Plasma Proteins ◽

Protein Composition ◽

Surface Protein ◽

Ubiquitin Proteasome System ◽

Sperm Capacitation ◽

Sperm Surface ◽

Ubiquitin Proteasome ◽

Seminal Plasma Proteins

Sperm capacitation, one of the key events during successful fertilization, is associated with extensive structural and functional sperm remodeling, beginning with the modification of protein composition within the sperm plasma membrane. The ubiquitin-proteasome system (UPS), a multiprotein complex responsible for protein degradation and turnover, participates in capacitation events. Previous studies showed that capacitation-induced shedding of the seminal plasma proteins such as SPINK2, AQN1, and DQH from the sperm surface is regulated by UPS. Alterations in the sperm surface protein composition also relate to the porcine β-microseminoprotein (MSMB/PSP94), seminal plasma protein known as immunoglobulin-binding factor, and motility inhibitor. MSMB was detected in the acrosomal region as well as the flagellum of ejaculated boar spermatozoa, while the signal disappeared from the acrosomal region after in vitro capacitation (IVC). The involvement of UPS in the MSMB degradation during sperm IVC was studied using proteasomal interference and ubiquitin-activating enzyme (E1) inhibiting conditions by image-based flow cytometry and Western blot detection. Our results showed no accumulation of porcine MSMB either under proteasomal inhibition or under E1 inhibiting conditions. In addition, the immunoprecipitation study did not detect any ubiquitination of sperm MSMB nor was MSMB detected in the affinity-purified fraction containing ubiquitinated sperm proteins. Based on our results, we conclude that UPS does not appear to be the regulatory mechanism in the case of MSMB and opening new questions for further studies. Thus, the capacitation-induced processing of seminal plasma proteins on the sperm surface may be more complex than previously thought, employing multiple proteolytic systems in a non-redundant manner.

Download Full-text

Cleavage of Binder of Sperm Protein 3 (BSP3), Which Binds Bull Sperm to Oviductal Epithelium, by Sperm Surface Serine Protease.

Biology of Reproduction ◽

10.1093/biolreprod/87.s1.437 ◽

2012 ◽

Vol 87 (Suppl_1) ◽

pp. 437-437

Author(s):

Pei-hsuan Hung ◽

Susan S. Suarez

Keyword(s):

Serine Protease ◽

Sperm Protein ◽

Sperm Surface ◽

Oviductal Epithelium ◽

Bull Sperm

Download Full-text

Functional Aspects of Seminal Plasma in Bird Reproduction

International Journal of Molecular Sciences ◽

10.3390/ijms21165664 ◽

2020 ◽

Vol 21 (16) ◽

pp. 5664

Author(s):

Julian Santiago-Moreno ◽

Elisabeth Blesbois

Keyword(s):

Seminal Plasma ◽

Ion Homeostasis ◽

Sperm Concentration ◽

Cellular Functions ◽

Functional Aspects ◽

Reproductive Techniques ◽

Sperm Survival ◽

Protein Components ◽

And Function

This review provides an updated overview of the seminal plasma composition, and the role of metabolic and protein components on the sperm function of avian species. In addition, the implication of seminal plasma on assisted reproductive techniques of birds was discussed. The semen of birds usually has exceptionally high sperm concentration with relatively little seminal plasma, but this contributes to very fast changes in sperm metabolism and function. The biochemical characteristics and physiological roles of the various seminal plasma components in birds (carbohydrates, lipids, amino acids, hormones, and proteins) are poorly understood. Seminal plasma content of proteins has an action on most cellular functions: metabolism, immunity, oxido-reduction regulation, proteolysis, apoptosis, ion homeostasis, and antimicrobial defenses. The variable amount of many proteins is related to a different fertility capacity of poultry sperm. The role of seminal plasma on semen conservation (chilling and freezing) remains largely a matter of speculation, as both inhibitory and stimulating effects have been found. Whereas the presence of seminal plasma did not seem to affect the sperm survival after freezing–thawing, DNA fragmentation is lower in the absence of seminal plasma. The molecular basis of the influence of seminal plasma on sperm cryo-resistance was also discussed in the present review.

Download Full-text