Carp Seminal Plasma Research Articles

Proteomic analysis of carp seminal plasma provides insights into the immune response to bacterial infection of the male reproductive system

Aeromonas salmonicida is recognized as a significant bacterial pathogen in ulcerative disease of cyprinid fish. However, the mechanism of immunity to these bacteria in common carp is still not well understood, especially the immune regulation in the gonad to bacterial infection. The aims of our study were to analyze changes in the seminal plasma proteome following A. salmonicida infection in carp males. The observed pathological changes in the tissue (liver, spleen, kidney and testis) morphology and upregulation of immune-related genes (tnfa2, il6a) confirmed the successful infection challenge. Using mass spectrometry-based label-free quantitative proteomics, we identified 1402 seminal plasma proteins, and 44 proteins (20 up- and 24 downregulated) were found to be differentially abundant between infected and control males. Most differentially abundant proteins were involved in the immune response mechanisms, such as acute phase response, complement activation and coagulation, inflammation, lipid metabolism, cell-cell and cell-matrix adhesion, creatine-phosphate biosynthesis and germ cell-Sertoli cell junction signaling. Bacterial infection also caused profound changes in expression of selected genes in the testis and hematopoietic organs, which contributed to changes in seminal proteins. The altered seminal proteins and bacterial proteins in seminal plasma may serve as valuable markers of infection in the testis.

Common carp (Cyprinus carpio) sperm reduction during short-term in vitro storage at 4 °C

This study was designed to optimize a short-term storage protocol for common carp sperm at 4 °C under aerobic condition. Sperm from individual males were collected directly with or without extenders. The results demonstrated that in general, it was similar effect to collect sperm directly in extenders and keeping sperm for 0.5 h after collection without extenders. Sperm was diluted with eight selected extenders (sperm: extender = 2:1, 1:1 and 1:9) and undiluted sperm was used as a control. Sperm and seminal plasma parameters (sperm motility, velocity, membrane integrity, sperm concentration, osmolality and pH in seminal plasma) were evaluated in sperm stored on ice under aerobic conditions at 0, 2, 4, 6 and 8 days post stripping (DPS) using the computer- assisted sperm analysis system. Results showed that 1:1 and 2:1 dilution maintained higher sperm function and more sperm for a longer period. After 8 DPS, the best sperm quality and quantity was recorded in the common carp seminal plasma supplemented with 50 mM NaCl, Cejko extender (2 mM CaCl2, 1 mM MgSO4, 20 mM Tris, 110 mM NaCl, 40 mM KCl, pH 7.5 and 310 mOsm/kg) supplemented with/without 25 mM KCl/NaCl. The reduction of spermatozoa number with time during short-term storage but varied according to different dilution ratios and extenders. At 8 DPS, sperm count has dropped by 22.9 % in a dilution of 1:1 compared to 50.3 % in sperm without dilution. Extenders with diluted 1:1, especially Cejko solution, largely postponed sperm reduction, 21.3 % compared to 55.5 % for sperm stored without extenders.

Characterization of carp seminal plasma Wap65-2 and its participation in the testicular immune response and temperature acclimation

Two functionally distinct isoforms of warm-temperature acclimation related 65-kDa protein (Wap65-1 and Wap65-2) with a role in the immune response are present in fish. To our knowledge, contrary to Wap65-1, Wap65-2 has neither been isolated nor functionally characterized in carp especially in reproductive system. The aim of this study was to characterize Wap65-2 and ascertain its functions in immune response and temperature acclimation within reproductive system. Wap65-2 corresponded to one of the most abundant proteins in carp seminal plasma, with a high immunologic similarity to their counterparts in seminal plasma of other fish species and a wide tissue distribution, with predominant expression in the liver. The immunohistochemical localization of Wap65-2 to spermatogonia, Leydig cells, and the epithelium of blood vessels within the testis suggests its role in iron metabolism during spermatogenesis and maintenance of blood-testis barrier integrity. Wap65-2 secretion by the epithelial cells of the spermatic duct and its presence around spermatozoa suggests its involvement in the protection of spermatozoa against damage caused by heme released from erythrocytes following hemorrhage and inflammation. Our results revealed an isoform-specific response of Wap65 to temperature acclimation and Aeromonas salmonicida infection which alters blood-testis barrier integrity. Wap65-2 seems to be related to the immune response against bacteria, while Wap65-1 seems to be involved in temperature acclimation. This study expands the understanding of the mechanism of carp testicular immunity against bacterial challenge and temperature changes, in which Wap65-2 seems to be involved and highlights their potential usefulness as biomarkers of inflammation and temperature acclimation.

Antioxidant defence system in protein fractions of common carp (Cyprinus carpio) seminal plasma

There are growing evidences that the damage which is caused to the spermatozoa by the reactive oxygen species (ROS) plays a key role in male infertility. The seminal plasma is endowed with many enzymatic and non-enzymatic antioxidants which protect the spermatozoa against oxidative stress. The present study was undertaken to compare the level of superoxide dismutase (SOD), glutathione reductase (GR) and glutathione peroxidase (GPx) in separated protein fractions of whole common carp Cyprinus carpio seminal plasma. Seminal plasma from six male common carp was separated into four fractions. The fractions differed from each other in their total seminal plasma protein content and antioxidant status. The highest value of SOD (2.81 ± 0.11 mU/mg protein) was found in fraction 4, and the lowest (1.83 ± 0.18 mU/mg protein) in fraction 1. There were significant variations (ANOVA; P = 0.05) in GR activity, mainly between fractions 1, 2, and 4. The lowest value of GPx activity (14.9 ± 0.4 mU/mg protein) was found in fraction 2; however, the GPx activity showed low variability among fractions. We conclude that distinct seminal plasma fractions differ in antioxidant capacity. The inclusion of fractions with high levels of SOD, GR, and GPx in sperm storage medium may enhance protection against oxidative stress and promote sperm survival during the in vitro storage.

Hormonal stimulation of carp is accompanied by changes in seminal plasma proteins associated with the immune and stress responses

Hormonal stimulation in common carp is a routine practice to enhance sperm production and control gamete maturation. This study aimed to compare the proteome of carp seminal plasma between control and Ovopel-induced males using two-dimensional differential in-gel electrophoresis. Ovopel induction increased sperm volume, total sperm count, seminal plasma osmolality, and pH and decreased seminal plasma protein concentration. In total, 36 spots were identified (23 up- and 13 downregulated), corresponding to 23 proteins differentially abundant in seminal plasma after Ovopel induction (p < .05; fold change 1.2). The majority of proteins were associated with the immune and stress responses including the transport protein (hephaestin), antiproteases (fetuin, α2-macroglobulin, TIMP2), complement components (C3, complement factor B/C2A), regulator of the coagulation cascade (plasminogen), modulators of the innate immune response, such as intelectin, ApoA and ApoE, and the cathepsin/cystatin system, and stress response (enolase1). In addition, hormonal stimulation seems to be related to the proteins involved in lipid metabolism, signal transduction, and tissue remodeling. Our results suggest that hormonal stimulation is not just concomitant with the hydration of testis but also induces the synthesis and secretion of seminal plasma proteins involved in sperm maturation and protection against stress induced by administration of the exogenous hormone. SignificanceIt is well known that hormonal stimulation of male fish induces the final maturation of spermatozoa. However, molecular and biochemical basis underlying hormone-induced changes in semen is unknown at present. This study for the first time reveals, using proteomic approach, that hormonal stimulation in addition to hydration of testis is accompanied by significant changes in seminal plasma proteins related mainly to immune and stress response, lipid metabolism, signal transduction and tissue remodeling. These changes are associated with gene expression and synthesis and secretion of seminal plasma proteins by reproductive tissues. Overall, our results provide a framework for understanding the molecular mechanism responsible for hormonal stimulation in the reproductive tract of fish males.

Metabolic fingerprinting of carp and rainbow trout seminal plasma

Rainbow trout and common carp are commercially important aquaculture fish species. To the best of our knowledge, the global composition of fish seminal plasma (SP) metabolites has never been studied. The aim of this study was to identify metabolites in carp and rainbow trout SP and to compare their relative abundances through the use of liquid chromatography-mass spectrometry (LC-MS)-based metabolic fingerprinting. Different solvents and sample/solvent ratios were tested for metabolite extraction. The largest number of metabolic features and the highest signal reproducibility were achieved using a 1:1 sample/acetone ratio for extraction. Accurate masses were searched against metabolite databases, and the identities of 48 and 40 metabolites for rainbow trout and carp SP, respectively, were confirmed using LC-MS/MS or through the standards. Most of the identified metabolites have not been previously described in fish SP. Several metabolites (amino acids, acylcarnitines, vitamins) were found in the SP of both species. However, differences between carp and rainbow trout SP metabolic fingerprints were observed. Certain metabolites appeared to be species-specific, e.g., propionic acid for carp and adipic and picolinic acids, homocitrulline and niacin for rainbow trout. Functional analysis revealed the involvement of SP metabolites in free radical scavenging, lipid and energy metabolism, molecular transport, cell death and survival, and inflammatory response. The identification of a high number of carp and rainbow trout seminal plasma metabolites provides new opportunities to develop novel biomarkers for sperm quality, optimise artificial reproduction and develop efficient cryopreservation procedures for these important aquaculture species.

Artificial insemination of African catfish (Clarias gariepinus) using cryopreserved sperm

In this study, we aimed to develop a practical protocol for using cryopreserved sperm for induced/wild/tank spawning of fish species with external fertilization. Experiments were carried out on African catfish (Clarias gariepinus) as a model species. Sperm was collected for cryopreservation and diluted with the cryomedium (266 mM fructose, 20% methanol) at a ratio of 1:1 with a final methanol concentration of 2.47 M pH7.73. Diluted sperm was loaded into 0.5-ml straws and cryopreserved by conventional protocol. Samples were prepared for insemination 24 h later, by thawing for 13 s in a 40 °C water bath, and centrifuged at 500 × g for 10 min at 20 °C. The seminal plasma, extender and external cryoprotectant were removed from the concentrated spermatozoa. The pellet was then resuspended in common carp (Cyprinus carpio) seminal plasma to reconstitute the lost volume. Sperm samples were then injected by a catheter into the ovarian cavity through the oviduct of the experimental females by the so-called ovarian lavage method in parallel with the intramuscular hormonal administration (5 mg carp pituitary/kg bw). Inseminated females (n = 9) were monitored for 10 h and ovulated eggs and spermatozoa stored in in the ovary were stripped. Stripped gamete samples were divided into two batches: (1) the first batch contained only the previously injected spermatozoa and was activated by aerated water (WA) immediately after stripping; (2) in case of the second batch additional, freshly stripped sperm was added as positive control to the stripped eggs before water activation (PC). Furthermore, five females were propagated by using the dry fertilization method (in vitro fertilization) as negative control (NC). All sperm and hormone injected females produced fertilised eggs with a hatching rate of 17.7 ± 13.2%, 12.5 ± 9.3%, and 61 ± 11.5% for WA, PC and NC respectively. These results indicate that artificial insemination based on using cryopreserved sperm with ovarian lavage can be a viable alternative to in vitro fertilization in a catfish species. Thus, we describe a proof of principle for a practical protocol for the induced/wild/tank spawning of an externally fertilising fish species with economical importance and propose that the protocol could be also applied to endangered marine or fresh fish species.

Serine-like proteolytic enzymes from common carp Cyprinus carpio L. seminal plasma are able to degrade sperm proteins

The application of zymography, with sperm proteins as a substrate, allowed for the first time the visualisation of two serine proteinases with a molecular weight of 76 and 163kDa from common carp Cyprinus carpio L. seminal plasma. Twenty four hours of incubation in a development solution with a pH of 7.5 and incubation at 37°C were the best conditions for the visualisation of serine proteinase; however, proteolysis was also observed at 4°C. Our results indicate that serine proteinase from common carp seminal plasma with a molecular weight of 76 and 163kDa may be involved in the degradative mechanism of sperm proteins. This mechanism may be responsible for the removal of damaged sperms by the digestion of native sperm proteins.

Proteomic identification of seminal plasma proteins related to the freezability of carp semen

The variation in sperm freezability among individuals within a fish species is a major factor justifying the identification of useful predictive indicators of cryopreservation success. It is unknown at present whether the protein composition of fish seminal plasma affects sperm freezability. Therefore, the aims of this study were to compare the proteome of carp seminal plasma from semen rated as good (GF) and poor (PF) freezability by two-dimensional difference gel electrophoresis followed by MALDI-TOF/TOF mass spectrometry. The semen was classified as GF and PF based on sperm motility assessment after freeze/thawing. Five spots representing three proteins were more abundant in GF, while ten spots representing seven proteins were more abundant in PF seminal plasma. The majority of proteins present in higher abundance in PF seminal plasma were associated with the innate immune response. On the other hand, higher freezability was associated with proteins involved in the maintenance of sperm membrane integrity and antioxidative protection. These results indicate that carp semen freezability levels may be related to different seminal plasma protein profiles. Lower usefulness of spermatozoa in cryopreservation may be related to previous infection or stress leading to sublethal changes to sperm structure. SignificanceSperm quality parameters such as motility, viability and sperm concentration have been used as predictive tools of sperm cryopreservation potential in fish species However, the usefulness of initial motility parameters as indicators of freezability varies among fish species and between individuals within a species. Recent studies in mammals revealed that male-to-male variability in cryoresistance can be attributed to differences in seminal plasma protein composition. To the best of our knowledge, no proteomic studies linking the protein composition of fish seminal plasma and freezing resilience have been performed in fish. Our results indicate for the first time that factors regulating how carp semen tolerate cryopreservation may be related to the different protein profiles of carp seminal plasma. The obtained results provide new insight into understanding the molecular mechanisms underlying cryoresistance of carp semen and provide a tool for the improvement of a long-term sperm preservation procedure.

Serine protease inhibitor Kazal-type 2 is expressed in the male reproductive tract of carp with a possible role in antimicrobial protection

The presence of the low-molecular-mass serine protease inhibitor Kazal-type (Spink) is a characteristic feature of vertebrate semen. Its main function is control of the serine protease in the acrosome, acrosin. Here we showed for the first time that Spink is present in the seminal plasma of carp, which have anacrosomal spermatozoa. Using a three-step isolation procedure that consisted in gel filtration and RP-HPLC and re-RP-HPLC, we isolated this inhibitor and identified it as serine protease inhibitor Kazal-type 2 (Spink2), a reproductive-derived member of the Spink family. The cDNA sequence of this inhibitor obtained from carp testis encoded 77 amino acids, including a 17 amino acids signal peptide; this sequence was distinct from fish Kazal-type inhibitors. The mRNA expression analysis showed that Spink2 is expressed predominantly in carp testis and spermatic duct. Immunohistochemical analysis demonstrated its localization in testis in Sertoli, Leydig and germ cells at all developmental stages (with the exception of spermatozoa) and in the epithelium of the spermatic duct. Aside from strong inhibition of trypsin, this inhibitor acts strongly against subtilisin and possesses bacteriostatic activities against Lactobacillus subtilis, Escherichia coli and Aeromonas hydrophila. The localization of Spink2 in carp reproductive tract suggests an important function in spermatogenesis and in maintenance of the microenvironment in which sperm maturation occurs and sperm are stored. Our results suggest that Spink2 from carp seminal plasma may play a role in antibacterial semen defense, protecting semen against unwanted proteolysis within the reproductive tract.

Protein profile of seminal plasma and functionality of spermatozoa during the reproductive season in the common carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss)

The purpose of the study was to analyze seminal plasma composition, sperm production, and sperm motility over the course of the spawning season in the common carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss). The highest mean percent of motile sperm (carp, 98.3 ± 1.6%; rainbow trout, 92.8 ± 5.6%) and highest spermatozoon velocity (carp, 286.3 ± 7.8 μm sec-1 ; rainbow trout, 245.3 ± 8.3 μm sec-1 ) were observed in the middle phase of the spawning period, at 5 sec post-activation. Sperm volume and concentration increased in the early spawning period, then decreased significantly toward the end of the season in both species. Seminal plasma osmolality was 262-270 mOsmol kg-1 from carp and 232-248 mOsmol kg-1 from rainbow trout, with little variation over the spawning period. Protein concentration in carp seminal plasma was stable throughout the reproductive season, whereas the highest protein level (2.1 ± 0.3 mg mL-1 ) in rainbow trout was observed in the middle phase of the spawning period. Seminal plasma composition in both species was analyzed using two-dimensional polyacrylamide gel electrophoresis combined with mass spectrometry. Thirteen differentially expressed protein spots in carp seminal plasma and sixteen spots in rainbow trout seminal plasma varied over the course of the reproductive season. The unique proteins identified are involved in the regulation of spermatogenesis, sperm motility, maintenance of sperm membrane lipid stability, and antioxidant protection. These results provide a deeper understanding of the role of fish seminal plasma proteins as well as a list of novel markers of sperm quality. Mol. Reprod. Dev. 83: 968-982, 2016 © 2016 Wiley Periodicals, Inc.

Identification and characterization of major form of the warm temperature acclimation-related 65-kDa protein in carp seminal plasma

Identification and characterization of major form of the warm temperature acclimation-related 65-kDa protein in carp seminal plasma

Identification of 5-15 kDa substances in carp seminal plasma using mass spectrometry

The objective of this study was to detect substances of 5–15 kDa in carp seminal plasma using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and to compare mass spectrometry profiles between two common carp lines. Resolved were seminal plasma proteins using tris – tricine SDS – PAGE. Also found were 19 mass spectra peaks of carp seminal plasma. A few low-molecular mass proteins were identified, including parvalbumin, apolipoprotein, histone H4 and H2A, and one hypothetical protein. Mass spectrometry was not useful for molecular profiling of carp breeding lines, but are potentially useful for comparative studies of cyprinids.

Characterization, expression and antibacterial properties of apolipoproteins A from carp (Cyprinus carpio L.) seminal plasma

Apolipoproteins A are multifunctional proteins that, in addition to contributing to lipid metabolism and transport, are associated with the innate immune system in fish. Using a three step isolation procedure consisting of affinity chromatography on Blue-Sepharose, delipidation and reverse phase HPLC we isolated apolipoproteins from carp seminal plasma and identified them as ApoA-I and Apo-14 kDa. Moreover, we provided the full-length cDNA sequence of ApoA-I encoding 257 amino acids including a 18 amino acid signal peptide and a 4 amino acid propeptide. Apolipoproteins corresponded to the most abundant proteins in carp seminal plasma. Both ApoA-I and Apo-14 kDa were represented by several proteoforms that differ both in molecular mass and isoelectric point. The proteoforms of ApoA-I characteristic for seminal plasma were distinguished from those of blood. Carp seminal plasma ApoA-I and Apo-14 kDa showed a high immunologic similarity to their counterparts in carp blood and seminal plasma of other Cyprinid species. The mRNA expression analysis and immunohistochemical study suggest synthesis and secretion of ApoA-I and Apo-14 kDa in the fish reproductive tract and suggest a role in spermatogenesis and the stabilization of sperm membrane. Moreover, ApoA-I displayed bactericidal activity against Escherichia coli and bacteriostatic activity against Aeromonas hydrophila which suggests that ApoA-I is associated with innate immune system of the fish reproductive tract.

Characterization of carp seminal plasma proteome in relation to blood plasma

The present study for the first time characterizes a diverse cohort of carp seminal and blood plasma proteins using the combination of protein fractionation by one-dimensional gel electrophoresis and high performance liquid chromatography electrospray ionization tandem mass spectrometry. Using this approach, we identified 137 proteins in carp seminal plasma and 88 proteins in carp blood plasma, most of which were newly identified in fish. Transferrin, serine proteinase inhibitors, apolipoproteins, complement C3 and Wap65 were present in high abundance in carp seminal plasma. In carp blood plasma, besides these proteins, immunoglobulins and macroglobulins were identified as major proteins. Comparative analysis of carp seminal and blood plasma proteome performed using 2D-DIGE revealed that in contrast to mammals the majority (1014 from 1240 spots) of carp seminal plasma proteins are blood proteins. Moreover, proteins more abundant in seminal plasma (99 from 1240 spots) were identified, including parvalbumin, isoforms of apolipoproteins, heat shock proteins, components of antioxidative system, matrix metalloproteinases, cathepsin D, enzymes of glycolysis and sperm structural proteins. These proteins are involved in the regulation of sperm motility, spermatogenesis, maintenance of sperm membrane lipid stability and antioxidant protection. This study enhances the basic knowledge concerning fish seminal plasma protein composition and their potential role in fish reproduction. Proteins similar or identical to blood plasma components are important for male reproductive physiology. Comparative study of blood and seminal plasma is especially justified in fish. Using 2D-DIGE we indicated that, in contrast to mammals, in carp seminal plasma most proteins are common for blood and seminal plasma, which possibly is related to a lack of accessory glands in reproductive tract of most fish. The proteins present in higher abundance in seminal plasma can be related to physiology of fish male reproduction including regulation of sperm motility, spermatogenesis, maintenance of sperm surface composition and antioxidant protection. Application of proteomics analysis to identify carp seminal and blood plasma proteins significantly extends current knowledge regarding the composition of fish seminal and blood plasma proteins and their relationship to higher vertebrates. Moreover, proteomic profiling of carp seminal plasma appears to be helpful for further understanding of the role of fish seminal plasma proteins in male reproductive tract as well as for identification of novel biomarkers for sperm quality.

Isolation, characterisation and cDNA sequencing of a new form of parvalbumin from carp semen

Parvalbumins (Pv) are calcium-binding proteins present mainly in the muscle and nervous system where they act as a Ca(2+) buffer. Our previous work demonstrated the presence of Pv-I in carp semen and indicated the presence of a second Pv (Pv-II). The purpose of the present work was to identify, purify and determine the full-length cDNA sequence of Pv-II from carp testis. Pv-II from seminal plasma was purified by ion-exchange chromatography (IEC) and preparative electrophoresis, while the Pv-II from spermatozoa was purified by IEC, gel filtration and preparative electrophoresis. The purified Pv-II was submitted to an analysis of molecular mass, isoelectric point (pI), amino-acid sequence and oligomerisation ability. The amino-acid sequence was used to construct primers and obtain the full-length cDNA sequence of seminal-specific Pv-II from carp testis. Analysis of the cDNA sequence indicated that carp-testis Pv-II was distinct from carp-muscle parvalbumins. Pv-II was distinct from Pv-I regarding sequence, molecular mass and pI. Both parvalbumins had the ability to form oligomers or to bind to other proteins. Carp seminal plasma had a protective effect against parvalbumin oligomerisation. Pv-II underwent post-translational modification such as n-acetylation and cysteinylation. The present study is the first to report the full-length cDNA sequence of parvalbumin from carp testis.

Identification of apolipoproteins AI and AII in carp and rainbow trout seminal plasma

Identification of apolipoproteins AI and AII in carp and rainbow trout seminal plasma

Comparative proteomics analysis of carp seminal and blood plasma

Comparative proteomics analysis of carp seminal and blood plasma

Identification of Kazal-type serine proteinase inhibitor in carp seminal plasma

Identification of Kazal-type serine proteinase inhibitor in carp seminal plasma

Carp transferrin can protect spermatozoa against toxic effects of cadmium ions

Cadmium is a widespread heavy metal that enters the aquatic environment and affects many processes involved in fish reproduction such as sperm motility. Fish seminal plasma proteins can protect spermatozoa against toxic effects of heavy metals. The objective of this study was to demonstrate the ability of a major carp seminal plasma protein-transferrin (TF) to bind cadmium ions and to neutralize the toxic effect of cadmium on carp sperm motility. To obtain a high quantity of carp seminal plasma TF necessary for the experiment, immunoaffinity chromatography as a one-step isolation procedure was established. The titration of TF with cadmium ions spectrophotometrically at 247nm revealed that TF binds cadmium ions at only one spectrophotometrically-sensitive binding site, which suggests that TF is capable of neutralizing the cadmium toxic effect. Indeed, the addition of carp TF to carp semen incubated with 50ppm cadmium for 48h led to about a four-times higher percentage of sperm motility (30.3±1.1%) in comparison to samples incubated with only 50ppm cadmium (8.2±5.2%). Similarly, higher values of other parameters of sperm movement measured by a computer-assisted sperm motility analysis system (VSL, VCL and ALH) were observed at the presence of transferrin. In conclusion, our study provides the first evidence that transferrin from carp seminal plasma can protect sperm motility from cadmium toxicity.