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Copyright of Acta Zoologica Lilloana is the property of Fundacion Miguel Lillo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fertilization mode may affect sperm characteristics, such as morphology, velocity, and motility. However, there is little information on how fertilization mode affects sperm evolution because several factors (e.g., sperm competition) are intricately intertwined when phylogenetically distant species are compared. Here, we investigated sperm characteristics by comparing seven externally and four internally fertilizing marine fishes from three different groups containing close relatives, considering sperm competition levels. The sperm head was significantly slenderer in internal fertilizers than in external fertilizers, suggesting that a slender head is advantageous for swimming in viscous ovarian fluid or in narrow spaces of the ovary. In addition, sperm motility differed between external and internal fertilizers; sperm of external fertilizers were only motile in seawater, whereas sperm of internal fertilizers were only motile in an isotonic solution. These results suggest that sperm motility was adapted according to fertilization mode. By contrast, total sperm length and sperm velocity were not associated with fertilization mode, perhaps because of the different levels of sperm competition. Relative testis mass (an index of sperm competition level) was positively correlated with sperm velocity and negatively correlated with the ratio of sperm head length to total sperm length. These findings suggest that species with higher levels of sperm competition have faster sperm with longer flagella relative to the head length. These results contradict the previous assumption that the evolution of internal fertilization increases the total sperm length. In addition, copulatory behavior with internal insemination may involve a large genital morphology, but this is not essential in fish, suggesting the existence of various sperm transfer methods. Although the power of our analyses is not strong because of the limited number of species, we propose a new scenario of sperm evolution in which internal fertilization would increase sperm head length, but not total sperm length, and change sperm motility. [ABSTRACT FROM AUTHOR]

Semen was collected from Polish Halfbred stallions. Twenty individuals from 3 to 4 years of age were selected for the study. At least one ejaculate from each stallion was collected and assessed. Sperm morphology was evaluated using Papanicolaou stain, SpermBlue®, and a complex of eosin and gentian stain, whereas unstained slides were used as control samples. Morphometric measurements were performed on 100 randomly selected sperm heads in each ejaculate. The length, width, perimeter, and surface area of the sperm head were measured. The frequency of nuclear vacuoles was determined as well. Tygerberg's strict criteria, which most precisely characterise the sperm head, were used in the morphological evaluation of the sperm. The results obtained indicate that in the case of staining with SpermBlue® and with eosin+gentian complex, the morphometry of the sperm head seems to be most similar to that observed in unstained smears. It also seems that neither shrinking nor swelling is uniform in the various staining techniques (Papanicolaou stain). Moreover, it appears that in comparison with unstained sperm, all methods caused the width of the head to increase as a result of swelling. [ABSTRACT FROM AUTHOR]

This study investigates the effects of melatonin on the sperm quality and testis weight after the combination of swimming exercise and nandrolone decanoate (DECA). Two groups of male Wistar rats were treated for eight weeks as follows; group A consist of CO (control), Sham, N (DECA), S (swimming) and NS (DECA plus swimming); and group B: Sham M (sham melatonin), M (melatonin), MN (melatonin plus DECA), MS (melatonin plus swimming), MNS (melatonin, DECA plus swimming). The motility of sperm was significantly improved in melatonin groups in comparison to N, S and NS groups (P≤0.05). The left testes weight was decreased in N, NS and MNS groups, and the right testes weight was decreased in N,S,NS, MS and MNS groups in compare with the control group. This study concluded that melatonin probably could improve the sperm motility and sex organs weight after the combination of DECA and exercise. [ABSTRACT FROM AUTHOR]

Few data exist about the presence and physiological role of Na+/H+ exchangers (NHEs) in the plasma membrane of mammalian sperm. In addition, the involvement of these channels in the ability of sperm to undergo capacitation and acrosomal reaction has not been investigated in any mammalian species. In the present study, we addressed whether these channels are implicated in these two sperm events using the pig as a model. We also confirmed the presence of NHE1 channels in the plasma membrane of ejaculated sperm by immunofluorescence and immunoblotting. The function of NHE channels during in vitro capacitation was analyzed by incubating sperm samples in capacitating medium for 300 min in the absence or presence of a specific blocker (DMA; 5-(N,N-dimethyl)-amiloride) at different concentrations (1, 5, and 10 µM); acrosome exocytosis was triggered by adding progesterone after 240 min of incubation. Sperm motility and kinematics, integrity of plasma and acrosome membranes, membrane lipid disorder, intracellular calcium and reactive oxygen species (ROS) levels, and mitochondrial membrane potential (MMP) were evaluated after 0, 60, 120, 180, 240, 250, 270, and 300 min of incubation. NHE1 localized in the connecting and terminal pieces of the flagellum and in the equatorial region of the sperm head and was found to have a molecular weight of 75 kDa. During the first 240 min of incubation, i.e., before the addition of progesterone, blocked and control samples did not differ significantly in any of the parameters analyzed. However, from 250 min of incubation, samples treated with DMA showed significant alterations in total motility and the amplitude of lateral head displacement (ALH), acrosomal integrity, membrane lipid disorder, and MMP. In conclusion, while NHE channels are not involved in the sperm ability to undergo capacitation, they could be essential for triggering acrosome exocytosis and hypermotility after progesterone stimulus. [ABSTRACT FROM AUTHOR]

Simple Summary: Genetic resource banks were created to preserve the genetic material of endangered, rare, valuable individuals or genetically relevant breeds. Sperm cryopreservation is a practical and widespread strategy to preserve these genetic materials. This study aimed to characterize the frozen-thawed sperm of the native pig breed Gochu Asturcelta, considering the effects of boar age and season of semen collection on post-thaw sperm quality. We found that the boar age did not have a significant effect on the sperm parameters assessed. However, the season significantly affected many of these parameters (motility, viability, acrosomal status, mitochondrial activity). In general, sperm samples collected in spring and summer showed higher quality post-thawing, the lowest in winter. Our findings demonstrated that the post-thawing sperm quality of Gochu Asturcelta was in the range of results for commercial breeds, bringing a good prospect for the use of assisted reproductive technologies in this local breed. Genetic resource banks (GRB) preserve the genetic material of endangered, valuable individuals or genetically relevant breeds. Semen cryopreservation is a crucial technique to reach these goals. Thus, we aimed to assess the sperm parameters of semen doses from the native pig breed Gochu Asturcelta stored at the GRB of Principado de Asturias (GRB-PA, Gijón, Spain), focusing on intrinsic and extrinsic (boar, season) factors. Two straws per boar (n = 18, 8–71 months of age) were thawed, pooled, and assessed after 30 and 150 min at 37 °C by CASA (computer-assisted sperm analysis system; motility and kinematic parameters) and flow cytometry (viability, acrosomal status, mitochondrial activity, apoptosis, reactive oxygen species, and chromatin status). The effects of age, incubation, and season on post-thawing quality were determined using linear mixed-effects models. Parameters were on the range for commercial boar breeds, with chromatin status (SCSA: fragmentation and immaturity) being excellent. Incubation decreased sperm quality and functionality. The boar age did not have a significant effect (p > 0.05), but the between-boar variability was significant (p < 0.001). The season significantly affected many parameters (motility, kinematics, viability, acrosomal status, mitochondrial activity), especially after 150 min of incubation. In general, samples collected in spring and summer showed higher quality post-thawing, the lowest in winter. In conclusion, the sperm doses from the Gochu Asturcelta breed stored at the GRB-PA showed excellent chromatin status and acceptable characteristics after thawing. Therefore, boar and seasonal variability in this autochthonous breed could be relevant for cryobank management. [ABSTRACT FROM AUTHOR]

Simple Summary: The efficiency of swine production measured as litter size influences the profitability of the pig industry. Furthermore, sow fertility potential depends in part on the boar semen quality and reproductive efficiency. The objective of this study is to compare boar sperm head size and morphometric features of shape to evaluate their relationships with reproductive success after artificial insemination (AI). A morphometric analysis of boar ejaculate reveals morphometrically separate sub-populations. The differences between sub-populations are displayed for sperm head size. In addition, sperm clustering into sub-populations did not have a predictive capacity on litter size variables. Nevertheless, the morphometric variables of the sperm may have a predictive, albeit reduced, capacity regarding litter size variables. The results of this study therefore open up possibilities for future assessments of fertility. The aim of the study was to compare the morphometric features of sperm head size and shape from the Pietrain line and the Duroc × Pietrain boar crossbred terminal lines, and to evaluate their relationship with reproductive success after artificial insemination of sows produced from crossbreeding the York, Landrace and Pietrain breeds. Semen samples were collected from 11 sexually mature boars. Only ejaculates with greater than 70% motility rate and <15% of abnormal sperm were used for artificial inseminations (AI) and included in the study. Samples were analyzed using an ISAS®v1 computer-assisted sperm analysis system for eight morphometric parameters of head shape and size (CASA-Morph). Sub-populations of morphometric ejaculates were characterized using multivariate procedures, such as principal component (PC) analysis and clustering methods (k-means model). Four different ejaculate sub-populations were identified from two PCs that involved the head shape and size of the spermatozoa. The discriminant ability of the different morphometric sperm variables to predict sow litter size was analyzed using a receiver operating characteristics (ROC) curve analysis. Sperm head length, ellipticity, elongation, and regularity showed significant predictive capacity on litter size (0.59, 0.59, 0.60, and 0.56 area under curve (AUC), respectively). The morphometric sperm sub-populations were not related to sow litter size. [ABSTRACT FROM AUTHOR]