Seminal Plasma Proteome as an Indicator of Sperm Dysfunction and Low Sperm Motility in Chickens

Abstract

Molecular mechanisms underlying sperm motility have not been fully explained, particularly in chickens. The objective was to identify seminal plasma proteins associated with chicken sperm motility by comparing the seminal plasma proteomic profile of roosters with low sperm motility (LSM, n = 4) and high sperm motility (HSM, n = 4). Using a label-free MS-based method, a total of 522 seminal plasma proteins were identified, including 386 (∼74%) previously reported and 136 novel ones. A total of 70 differentially abundant proteins were defined, including 48 more-abundant, 15 less-abundant, and seven proteins unique to the LSM group (specific proteins). Key secretory proteins like less-abundant adhesion G-protein coupled receptor G2 (ADGRG2) and more-abundant serine peptidase inhibitor Kazal-type 2 (SPINK2) in the LSM suggested that the corresponding secretory tissues played a crucial role in maintaining sperm motility. Majority (80%) of the more-abundant and five specific proteins were annotated to the cytoplasmic domain which might be a result of higher plasma membrane damage and acrosome dysfunction in LSM. Additionally, more-abundant mitochondrial proteins were detected in LSM seminal plasma associated with lower spermatozoa mitochondrial membrane potential (ΔΨm) and ATP concentrations. Further studies showed that the spermatozoa might be suffering from oxidative stress, as the amount of spermatozoa reactive oxygen species (ROS) were largely enhanced, seminal malondialdehyde (MDA) concentrations were increased, and the seminal plasma total antioxidant capacity (T-AOC) were decreased. Our study provides an additional catalogue of chicken seminal plasma proteome and supports the idea that seminal plasma could be as an indicator of spermatozoa physiology. More-abundant of acrosome, mitochondria and sperm cytoskeleton proteins in the seminal plasma could be a marker of sperm dysfunction and loss of motility. The degeneration of spermatozoa caused by the reduced seminal T-AOC and enhanced oxidative stress might be potential determinants of low sperm motility. These results could extend our understanding of sperm motility and sperm physiology regulation.

Exosome Composition and Seminal Plasma Proteome: A Promising Source of Biomarkers of Male Infertility

“…Remarkably, the seminal proteomic profile may be indicative of genital tract dysfunctions and, therefore, serve as a biomarker of infertility [ 3 , 10 , 35 , 36 ]. In this regard, although exosomes isolated from SP of normo-, astheno- and azoospermic patients display similar features in terms of shape, size and expression of typical exosomal markers, they differ in their cargo.…”

Functional Aspects of Seminal Plasma in Bird Reproduction

“…The mechanisms of SST filling and emptying are not well known (sperm stratification, displacement of previous ejaculates or passive sperm loss [43]), but when a polyandrous female mates with multiple males (e.g., chicken, capercaillie, red-legged partridges), it is the sperm of the last male that usually fertilizes most of the eggs. Many seminal proteins involved in calcium metabolism [14] and mitochondrial functions [23], seem to influence the variation of sperm velocity. The velocity of sperm may involve the number of sperms that arrive at the SSTs, and thus securing last male precedence [44].…”

“…They include different metabolic functions, immunity, oxido-reduction actors and regulation, proteolysis, apoptosis, ion homeostasis, antimicrobial defenses and also epigenetic actors such as histones [11,12,14,18,19,23].…”

“…As an example, one of the enzymes important for fertilization liberated by the acrosome reaction is acrosin. The active form of acrosin was found in the seminal plasma of chickens and turkeys [19,23,73]. Acrosin is more abundant in the seminal plasma of subfertile sperm of roosters of highly different genetic background [19,22,23] and in submotile sperm of a Chinese local breed [23].…”

“…A small number of studies focused on other domestic (i.e., Japanese quails, emu) or wild species (i.e., red jungle fowl, partridges, sparrows, budgerigar) [13][14][15][16][17]. In the last ten years, developments in biochemical and omics methods allowed for improving our knowledge of the seminal components and of the underlying mechanisms [12,[18][19][20][21][22][23]. The presence of seminal plasma in the bird sperm in vitro storage media significantly influences the short-and long-term success of sperm conservation.…”