Proteomic analysis of seminal plasma and sperm cells and their associations with semen freezability in Guzerat bulls1

Abstract

The objective of the present study was to describe the relationship of seminal plasma and total sperm cell proteins with the semen freezability parameters of Guzerat bulls. Thirteen bulls were subjected to breeding soundness evaluation. Semen samples were collected, cryopreserved, and then post-thawing sperm kinetics were assessed, where high ( = 7) and low ( = 6) freezability groups were defined. Seminal plasma and total sperm proteins from the 2 groups were separated by 2-dimensional SDS-PAGE, and spots were identified by mass spectrometry. Semen parameters post-cryopreservation were as follows in the high and low freezability groups, respectively: mean total motility, 52.4 ± 20.5 and 13.7 ± 3.9; percentage of normal sperm, 89.0 ± 2.6 and 64.7 ± 14.0; and reactivity of hypo-osmotic swelling test, 38.9 ± 4.7 and 13.6 ± 3.7. Three seminal plasma proteins (osteopontin-K, DNase γ precursor, and DNASE1L3) and 6 proteins from sperm cells (acrosome formation-associated factor isoform 2, annexin A1, disintegrin and metalloproteinase domain-containing protein 2, dihydrolipoyl dehydrogenase, and glyceraldehyde-3-phosphate dehydrogenase) were highly expressed ( < 0.05) in the high freezability group. Another 6 seminal plasma proteins (acrosin inhibitor 1, glutathione peroxidase 3, metalloproteinase inhibitor 2, ephrin-A1, annexin A1, and platelet-activating factor acetylhydrolase) were significantly higher ( < 0.05) in the low freezability group. We described the associations of seminal plasma and sperm cell proteins with post-thawing sperm viability of Guzerat bulls raised in a typical semiarid environment. Such associations indicate that specific seminal plasma proteins more abundant in bulls of low semen freezability may be a response to an early oxidative stress that is not detected by conventional prefreezing semen evaluation. Moreover, specific sperm proteins were more associated with good freezability. The results presented here can serve as guidelines for future research aiming to develop better extenders and/or to improve bull semen selection for cryopreservation.

Sperm Cryodamage in Ruminants: Understanding the Molecular Changes Induced by the Cryopreservation Process to Optimize Sperm Quality

“…Other studies conducted in bull, ram and buck revealed that quantitative variations in seminal plasma and sperm proteins also appeared between males [90][91][92][93][94][95][96], which could explain in part the individual variability observed in sperm freezability [97,98]. Males are frequently categorized as good or bad freezers depending on their post-thaw sperm quality; however, molecular biomarkers could predict more efficiently sperm cryotolerance before freezing-thawing in different individuals [10].…”

“…Among them, proteins involved in energy metabolism, motility regulation and sperm membrane protection increased in abundance in males classified as good freezers (Table 1). These changes could explain the greater sperm viability, mitochondrial activity and motility of good freezers compared to bad freezers [90][91][92][93][94][95][99][100][101]. In this context, freezability biomarkers can be a useful tool to select those males with a superior sperm freezing resilience.…”

Effects of increased scrotal temperature on semen quality and seminal plasma proteins in Brahman bulls

“…ANXA1 and PAFA were both shown to be significantly higher in bulls with low sperm freezability. However, in the same study, ANXA1 was more pronounced in sperm protein extracts from bull with high freezability (Rego et al, 2016). These studies support that ANXA1 is involved in promotion of membrane aggregation and fusion events and likely involved in membrane repair (Rescher & Gerke, 2004).…”

“…The protein is associated with the cell surface and is involved in epithelial cell proliferation, direct cell migration, and angiogenesis (Coulthard et al, 2012). It has been identified to be increased in bulls with low freezability, and speculated to be involved in inflammatory response, with increases occurring in response to oxidative stress (Rego et al, 2016). In the same study Acrosin inhibitor 1 (SPINK6) was shown to be negatively associated with postthaw sperm motility in B. indicus bulls; where a higher acrosin release from the acrosome before cryopreservation, may result in reduced cryotolerance (Rego et al, 2016).…”

“…It has been identified to be increased in bulls with low freezability, and speculated to be involved in inflammatory response, with increases occurring in response to oxidative stress (Rego et al, 2016). In the same study Acrosin inhibitor 1 (SPINK6) was shown to be negatively associated with postthaw sperm motility in B. indicus bulls; where a higher acrosin release from the acrosome before cryopreservation, may result in reduced cryotolerance (Rego et al, 2016). In our study the protein was in spots associated with HD in Period 2.…”