Sperm Protein Profile Research Articles

Physico-chemical properties and protein profiles of sperm from three freshwater chondrostean species: a comparative study among Siberian sturgeon (Acipenser baerii), sterlet (Acipenser ruthenus) and paddlefish (Polyodon spathula)

Summary Physico-chemical properties (spermatozoa motility, spermatozoa concentration, seminal plasma protein concentration, osmolality, pH, ions) and sperm protein profiles were evaluated in three Acipenseriforme species [Siberian sturgeon (Acipenser baerii), sterlet (Acipenser ruthenus) and paddlefish (Polyodon spathula)]. The spermatozoa velocity was observed significantly highest in sterlet and lowest in Siberian sturgeon (P < 0.05). Spermatozoa velocity was positively correlated to pH and the concentration of Na+ in seminal plasma in all species examined. Other tested parameters, in particular the concentration of K+, expressed species specific patterns, which could be linked to taxonomical status of species. The protein profiles of seminal plasma indicated a protein band with a molecular weight of 32.6 kDa exclusively detected in paddlefish. In spermatozoa, 95 protein spots were detected in Siberian sturgeon and sterlet, respectively, whereas only 70 spots were observed in paddlefish. Each spermatozoa protein map expressed a strong species specific pattern, which offers a basic benchmark to trace molecular differences among Acipenseriformes. It can be concluded that results presented in this study could be applied for successful reproduction management and cryopreservation protocols of these endangered species.

Physico-biochemical parameters and protein profiles of sperm from beluga Huso huso

Summary Basic physico-biochemical parameters and protein profiles of sperm from beluga (Huso huso), have been evaluated. The results show a stable spermatozoan velocity (ranging from 136.23 ± 5.63 to 105.78 ± 5.27 μms−1) and motility during 2 min post activation, as well as a long duration of the overall spermatozoa motility period (up to 5 min). Mean values were determined for seminal plasma protein concentration (0.29 ± 0.16 mg ml−1), spermatozoa concentration (0.28 ± 0.27 × 109 spz ml−1), seminal plasma osmolality (51.33 ± 4.91 mOsmol kg−1), the pH (8.49 ± 0.01) and Na+ (18.97 ± 3.65 mm), K+ (2.83 ± 1.36 mm), Ca2+ (0.19 ± 0.06 mm), Mg2+ (0.49 ± 0.23 mm) and Cl− (6.33 ± 0.58 mm) concentrations. Moreover, in seminal plasma, five protein bands with molecular weights (MW) of 71, 49, 46, 34, 29 kDa were identified. In spermatozoa, about 100 spots with molecular weights varying from 26.5 to 107 kDa and iso-electric points ranging from 5 to 9.5 were found. The observed physiological and biochemical properties, together with protein patterns, should be considered for the development of methods for controlled reproduction and sperm cryopreservation for the highly endangered beluga sturgeon.

Modified Expression of Several Sperm Proteins after Chronic Exposure to the Antiandrogenic Compound Vinclozolin

Little is known about the molecular impact of in vivo exposure to endocrine disruptors (EDs) on sperm structures and functions. We recently reported that the lifelong exposure of rats to the antiandrogenic compound vinclozolin results in low epididymal weight, changes in sperm kinematic parameters, and immature sperm chromatin condensation, together with the impairment of several fertility end points. These results led us to focus specifically on possible molecular abnormalities in sperm. Sperm samples were recovered from the frozen epididymides of rats exposed during the previous study. The proteins present in the samples from six exposed and six control rats were analyzed in pairs, by two-dimensional fluorescence difference gel electrophoresis, to investigate possible exposure-induced changes to sperm protein profiles. Twelve proteins, from the 380 matched spots observed in at least five gels, were present in larger or smaller amounts after vinclozolin exposure. These proteins were identified by mass spectrometry, and several are known to play a crucial role in the sperm fertilizing ability, among which, two mitochondrial enzymes, malate dehydrogenase 2 and aldehyde dehydrogenase (both of which were present in smaller amounts after treatment) and A-kinase anchor protein 4 (larger amounts of precursor after treatment). Finally, Ingenuity Pathway Analysis revealed highly significant interactions between proteins over- and underexpressed after treatment. This is the first study to show an association between in vivo exposure to an ED and changes to the sperm protein profile. These modifications may be at least partly responsible for the reproductive abnormalities and impaired fertility recently reported in this rat model of vinclozolin exposure.

Role of translation by mitochondrial‐type ribosomes during sperm capacitation: An analysis based on a proteomic approach

Mammalian spermatozoa contain a complex population of mRNAs, some of which have been demonstrated to be translated de novo by mitochondrial-type ribosomes using D-chloramphenicol (CP), a specific inhibitor of mitochondrial translation. However, little is known about the functions of these mRNAs in mature sperm. In the present study, differential proteomic approaches were applied to study sperm protein profiles translated by mitochondrial-type ribosomes using the inhibitor CP and 44 proteins were identified with lower expression in CP-treated sperm in comparison to capacitated sperm (ratio >or= 1.5, p<0.05). Results of Western blot and real-time PCR suggest that four proteins were translated by mitochondrial-type ribosomes. Bioinformatics analysis indicated that 26 of 44 proteins were involved in some critical processes correlated to sperm-egg interaction event. In addition, Mups, whose functions in reproduction have never been studied, were chosen for further study. Our results showed that Mups proteins were localized to the acrosome and flagellum of precapacitated sperm, and were also expressed in the equatorial segment of capacitated sperm. The depletion of Mups using neutralizing antibodies significantly inhibited capacitation in a dose-dependent manner, subsequently inhibited acrosome reaction and sperm-egg fusion. In summary, mitochondrial translation during capacitation can store proteins beneficial for sperm-egg interaction.

Effects of cooling, cryopreservation and heating on sperm proteins, nuclear DNA, and fertilization capability in mouse

In the present study, we used confocal microscopy and electrophoresis to study the effects of heating to 5 or 100 degrees C or cooling to 4 degrees C or -- 196 degrees C on the stability of sperm proteins and DNA. We used intracytoplasmic sperm injection (ICSI) to determine the fertilizing capability of treated spermatoza. It was shown that sperm cryopreservation at - 196 degrees C or cooling at 4 degrees C altered neither protein and DNA profiles nor the sperm fertilization capability, while the protein and DNA profiles of sperm heated at 100 degrees C were irreversibly degraded and inactivated. The proteins of sperm were severely damaged while the nuclear DNA still maintained its integrity when heated to 58 degrees C. Observation by laser confocal microscopy showed that after being heated to 58 degrees C and 100 degrees C, the nuclear of mouse sperm lost their ability to activate oocytes and they could not transform to male pronuclei though the membrane of some sperm could degrade and induce the formation of sperm asters in ICSI oocytes. The results indicate that the use of 58 degrees C heating only causes the degradation of sperm proteins, while the 100 degrees C heating elicits the irreversible degradation of both sperm proteins and nuclear DNA, and the damage of sperm proteins is primarily responsible for the observed decrease in sperm fertilizing capability.

Effect of cyproterone acetate on structure and function of rhesus monkey reproductive organs

A low dose of Cyproterone acetate (CPA; 1 mg/kg body weight/day for 70 days) was administered to adult male rhesus monkeys to assess its effects on testicular and epididymal structure and function in a nonhuman primate species. CPA caused extensive degenerative changes in morphology of seminiferous, efferent duct, and epididymal epithelia, including decrease in diameter of seminiferous and epididymal tubules and their lumen, height of epididymal epithelium, and an increase in intertubular connective tissue. The protein profile of spermatozoa showed alterations during their epididymal transit in control and CPA-treated monkeys. In CPA-treated animals, 19 polypeptides were acquired and nine were eliminated during epididymal transit in contrast to acquisition of 12 and loss of 14 polypeptides in control animals. Treatment with CPA also resulted in the appearance of 14 new polypeptides in epididymal cytosol and luminal fluid, probably of lysosomal origin. The protein pattern of caput and cauda epididymal tubule cytosol, maintained in organ culture and exposed to 100 microM CPA for 3 days, showed absence of eight polypeptides. These results indicate that even at the low dose used in this study, CPA has caused spermatogenic arrest, degenerative changes in the epididymal structure, and alterations in epididymal and sperm protein profile. Suppression of serum testosterone levels indicates the need for androgen supplementation if CPA is to be used for male contraception.