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FJ Peña M Plaza Davila BA Ball EL Squires P Martin Muñoz C Ortega Ferrusola C Balao da Silva 《Reproduction in domestic animals》2015,50(4):529-537
The traditional assessment of stallion sperm comprises evaluation of sperm motility and membrane integrity and identification of abnormal morphology of the spermatozoa. More recently, the progressive introduction of flow cytometry is increasing the number of tests available. However, compared with other sperm structures and functions, the evaluation of mitochondria has received less attention in stallion andrology. Recent research indicates that sperm mitochondria are key structures in sperm function suffering major changes during biotechnological procedures such as cryopreservation. In this paper, mitochondrial structure and function will be reviewed in the stallion, when possible specific stallion studies will be discussed, and general findings on mammalian mitochondrial function will be argued when relevant. Especial emphasis will be put on their role as source of reactive oxygen species and in their role regulating sperm lifespan, a possible target to investigate with the aim to improve the quality of frozen–thawed stallion sperm. Later on, the impact of current sperm technologies, principally cryopreservation, on mitochondrial function will be discussed pointing out novel areas of research interest with high potential to improve current sperm technologies. 相似文献
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The biological nature of age‐related declines in fertility in males of any species, including stallions, has been elusive. In horses, the economic costs to the breeding industry are frequently extensive. Mitochondrial function in ejaculated sperm, which is essential for sperm motility, is reflected by adenosine triphosphate production, mitochondrial oxidative efficiency and production of reactive oxygen species, and that this balance may become compromised in ageing stallions and during the process of cryopreservation. This presentation will focus on mitochondrial integrity and function as an avenue for understanding the pathophysiology of sperm when undergoing cryopreservation and male ageing. We discuss the importance of understanding the differences and similarities of sperm mitochondria to that of somatic cells regarding structure and mitochondrial biochemistry relating to sperm function. The roles of oxidative phosphorylation and glycolysis in sperm mitochondria are outlined as is the method of determining oxygen consumption and calcium homoeostasis in sperm mitochondria. Further, we outline the role of oxidative stress and reactive oxygen species. 相似文献
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哺乳动物精子线粒体是维持精子活力的关键细胞器，对精子超激活运动、获能、顶体反应及受精等过程起到重要的调节作用。哺乳动物精子线粒体特有的形态特征与特异性酶异构体使其具有独特动力学和调节特性。精子线粒体中发生的氧化磷酸化过程是维持精子运动的重要途径，该过程产生的活性氧对精子功能的维持具有重要作用，但过量可能导致精子损伤，加速精子凋亡。哺乳动物精子质膜磷脂酰丝氨酸外翻和相关半胱氨酸蛋白酶激活级联反应引起细胞凋亡。区别于体细胞线粒体，精子线粒体钙信号可能并未参与精子固有的凋亡途径，作为衡量线粒体功能的敏感指标，其对线粒体膜电位和耗氧量的检测研究至关重要。哺乳动物精子线粒体具有自身的遗传系统，线粒体基因拷贝数可能作为无创衡量精子质量和受精能力的标记。作者重点阐述了哺乳动物精子线粒体的结构、线粒体鞘的形成及其生物功能，包括发生在线粒体中的氧化磷酸化过程、活性氧对精子的利与弊、线粒体参与钙稳态与细胞凋亡过程；介绍了线粒体膜电位和耗氧量的检测，简述了线粒体基因组的研究进展，为进一步探讨线粒体所涉及的精子功能机制奠定基础。 相似文献
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JDA Losano DSR Angrimani A Dalmazzo BR Rui MM Brito CM Mendes GKV Kawai CI Vannucchi MEOA Assumpção VH Barnabe M Nichi 《Reproduction in domestic animals》2017,52(2):289-297
Studies have demonstrated the importance of mitochondria to sperm functionality, as the main source of ATP for cellular homoeostasis and motility. However, the role of mitochondria on sperm metabolism is still controversial. Studies indicate that, for some species, glycolysis may be the main mechanism for sperm energy production. For ram sperm, such pathway is not clear. Thus, we evaluated ram sperm in response to mitochondrial uncoupling and glycolysis inhibition aiming to assess the importance of each pathway for sperm functionality. Statistical analysis was performed by the SAS System for Windows, using the General Linear Model Procedure. Data were tested for residue normality and variance homogeneity. A p < .05 was considered significant. Groups treated with the mitochondrial uncoupler Carbonyl cyanide 3 chlorophenylhydrazone (CCCP) showed a decrease in the percentage of cells with low mitochondrial activity and high mitochondrial membrane potential. We also observed that the highest CCCP concentration promotes a decrease in sperm susceptibility to lipid peroxidation. Regardless the lack of effect of CCCP on total motility, this substance induced significant alterations on sperm kinetics. Besides the interference of CCCP on spermatic movement patterns, it was also possible to observe such an effect in samples treated with the inhibitor of glycolysis (2‐deoxy‐d ‐glucose, DOG). Furthermore, treatment with DOG also led to a dose‐dependent increase in sperm susceptibility to lipid peroxidation. Based on our results, we suggest that the glycolysis appears to be as important as oxidative phosphorylation for ovine sperm kinetics as this mechanism is capable of maintaining full motility when most of the cells have a low mitochondrial membrane potential. Furthermore, we found that changes in the glycolytic pathway trough glycolysis inhibition are likely involved in mitochondrial dysfunction and sperm oxidative unbalance. 相似文献
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RJ Aitken GN De Iuliis Z Gibb MA Baker 《Reproduction in domestic animals = Zuchthygiene》2012,47(Z4):7-14
Our ability to diagnose and treat male infertility is gradually improving in concert with advances in our understanding of the molecular mechanisms underpinning defective sperm function. In this context, one of the factors to emerge as a major causative agent in male infertility is oxidative stress. Spermatozoa are particularly susceptible to such stress because they are exceptionally rich in vulnerable substrates such as polyunsaturated fatty acids, proteins and DNA. The lack of sperm cytoplasm also provides these cells with little capacity to protect themselves from oxidative attack or to effect any repair, should damage occur. Similarly, sperm chromatin is in a quasi-crystalline state and has very little capacity to respond to any DNA damage induced by oxidative attack. When the latter does occur, it appears to be initiated by reactive oxygen species (ROS) generated by the sperm mitochondria. These free radicals attack the lipids present in the sperm mitochondria generating electrophilic aldehydes, which bind to components of the mitochondrial electron transport chain stimulating yet more ROS production. The oxidative stress created via this self-propagating mechanism initiates an apoptotic cascade as a result of which the spermatozoa loose their capacity for fertilization and suffer damage to their DNA. Phosphatidylserine externalization is a late event in sperm apoptosis and may facilitate the silent phagocytosis of moribund cells in the female reproductive tract, that is, the phagocytosis of senescent spermatozoa without the accompanying generation of an inflammatory response. Encouragingly, the involvement of oxidative stress in the aetiology of male infertility has opened up new opportunities for therapeutic interventions involving the judicious administration of nucleophiles and other forms of antioxidants. 相似文献
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Caballero I Parrilla I Almiñana C del Olmo D Roca J Martínez EA Vázquez JM 《Reproduction in domestic animals = Zuchthygiene》2012,47(Z3):12-21
Seminal plasma (SP) is known to play an important role in mammalian fertilization. However, the variability found in its composition among species, males and even fractions of the same ejaculate has made difficult to completely understand its effect in sperm function. Proteins are one of the major SP components that modulate sperm functionality. During the last years, intensive work has been performed to characterize the role of these proteins. They have been found to influence sperm capacitation, formation of the oviductal sperm reservoir and sperm-oocyte interaction. Sperm biotechnologies, such as sperm cryopreservation and flow cytometric sex-sorting, that involve a substantial dilution of the SP are detrimental to sperm quality. Attempts to improve the outcome of these biotechnologies include the restoration of SP, which has produced contradictory results. To overcome this variability, different research groups have proposed the application of isolated SP proteins. Herein, we will review the current knowledge in the role of the major SP proteins as modulators of sperm functionality. Furthermore, we will discuss the possible applications of the SP proteins in sperm cryopreservation and flow cytometric sex-sorting. 相似文献
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本试验探讨了氟对小鼠附睾中成熟精子超微结构的影响,为氟的生殖毒性研究与检测提供依据。选取8周龄性成熟雄性昆明小鼠20只,随机分为4组,对照组小鼠饮用蒸馏水,低、中和高氟组小鼠分别饮用含25、50和100 mg/L氟化钠的蒸馏水,于45 d后断颈处死小鼠,取小鼠附睾尾,经2.5%戊二醛固定后,采用透射电镜观察小鼠附睾中成熟精子的超微结构变化。与对照组相比,低氟组小鼠精子头部质膜断裂,部分脱落,个别线粒体肿胀、形态模糊;中氟组精子头部质膜脱落,顶体部分缺失,线粒体形状不规则,嵴间腔扩大;高氟组精子头部质膜脱落,线粒体排列不规则,出现空泡化,嵴结构模糊。结果表明,氟暴露小鼠附睾中成熟精子头、尾部中段均有不同程度的结构改变,尤以线粒体出现较明显的异常,且氟浓度越高,精子超微结构损伤越严重。 相似文献
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Camelid semen is characterized by a highly viscous, low-volume ejaculate with a low concentration of spermatozoa that exhibit low progressive motility. The viscous seminal plasma is currently the major impediment to the development of assisted reproductive technologies (ARTs) in camelids. To advance ARTs such as sperm cryopreservation and artificial insemination in camelids, it is necessary to identify the cause of the viscosity and gain an understanding of the role of seminal plasma components on sperm function and fertility. Numerous compounds and proteins have been identified as mediators of sperm function and predictors of fertility in other livestock species, and understanding the importance of specific proteins has progressed the success of ARTs in these species. Current knowledge on the components of camelid seminal plasma is outlined, together with the implications of these components for the development of ARTs in camelids. The cause of semen viscosity, as well as proteins that are present in camelid seminal plasma, is described for the first time. Seminal plasma components are compared with those of other species to hypothesize their role in sperm function and fertility. 相似文献
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Yongsheng TIAN Jing JIANG Na WANG Wenshan QI Jieming ZHAI Bo LI You LIANG Youming CHEN Chuanjun YANG Songlin CHEN 《The Journal of reproduction and development》2015,61(4):333-339
In order to develop excellent germplasm resources for giant grouper (Epinephelus lanceolatus), cryopreservation of giant grouper sperm was examined in the present study. Firstly, 13 kinds of sperm dilution (ELS1-3, EM1-2, TS-2, MPRS, ELRS0-6) were prepared with physiological salt, sucrose, glucose and fetal bovine serum. The physiological parameters of ELRS3 (ratio of fast motion, ratio of slow motion, time of fast motion, time of slow motion, lifespan and motility) and ELS3 (sperm ratio of slow motion, time of slow motion and motility) were significantly higher than those of the other dilutions (P < 0.05). Secondly, after adding 15% DMSO and 10% FBS to ELRS3 and ELS3, most physiological parameters of frozen sperm were also significantly higher than the other gradients (P < 0.05), and sperm motility was as high as 63.68 ± 4.16% to74.75 ± 12.71% (fresh sperm motility, 80.70 ± 1.37% to 80.71 ± 1.49%). Mixed with the above dilutions, a final volume of
105 ml semen was cryopreserved. Finally, the sperm of giant grouper cryopreserved with cryoprotectants (ELRS3 + 15% DMSO + 10% FBS) was used for electron-microscopic observation and crossbreeding with red-spotted groupers (Epinephelus akaara). The electron-microscopic observation revealed that part of the frozen-thawed sperm was cryodamaged, e.g., flagellum fracturing and mitochondria falling out, while the ultrastructure of sperm membrane, mitochondria and flagellum remained intact. Also, the fertilization and hatchability rates of giant grouper frozen sperm and red-spotted grouper eggs were as high as 94.56% and 75.56%, respectively. Thus, a technique for cryopreservation of giant grouper sperm was successfully developed and applied to crossbreeding with red-spotted grouper eggs. 相似文献
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Spermatozoa are vulnerable to oxidative attack because they contain an abundance of polyunsaturated fatty acids that are susceptible to lipid peroxidation. In addition, functionally important proteins and DNA are also subject to oxidative modification and adduction by aldehydes, such as 4-hydroxynonenal (4HNE), generated as a consequence of the peroxidative process. The proteins adducted by 4HNE include elements of the mitochondrial electron transport chain, such as succinic acid dehydrogenase. The net result of such electrophilic attack is to stimulate generation of mitochondrial reactive oxygen species (ROS) in a self-perpetuating lipid peroxidation–ROS generation cycle that ultimately triggers the intrinsic apoptotic pathway, leading to a rapid loss of motility and cell death. A major point of difference between apoptosis in spermatozoa and somatic cells is that in the former, nuclear DNA is located in a compartment (the head) separate from the mitochondria and most of the cytoplasm (the midpiece). As a result, nucleases activated and released in the midpiece during apoptosis cannot gain access to the DNA in the sperm head in order to cleave the DNA. However, the ROS generated during apoptosis can readily gain access to the sperm nucleus and generate oxidative base adducts, typically 8-hydroxy, 2′-deoxyguanosine (8OHdG), which are converted into abasic sites by 8-oxoguanine glycosylase (OGG1), the only enzyme of the base excision repair pathway possessed by spermatozoa. These abasic sites subsequently become the foci of DNA fragmentation. Because defective sperm function and DNA damage are frequently associated with oxidative stress, there is a great deal of interest in the use of antioxidants in a therapeutic context. This presentation examines the fundamental relationships between oxidative stress and sperm function and considers the implications of recent findings for the management of sperm function and fertility in stallions. 相似文献
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Flow Cytometric Chromosomal Sex Sorting of Stallion Spermatozoa Induces Oxidative Stress on Mitochondria and Genomic DNA 
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下载免费PDF全文 CM Balao da Silva C Ortega‐Ferrusola JM Morrell H Rodriguez Martínez FJ Peña 《Reproduction in domestic animals》2016,51(1):18-25
To date, the only repeatable method to select spermatozoa for chromosomal sex is the Beltsville sorting technology using flow cytometry. Improvement of this technology in the equine species requires increasing awareness of the modifications that the sorting procedure induces on sperm intactness. Oxidative stress is regarded as the major damaging phenomenon, and increasing evidence regards handling of spermatozoa – including sex sorting – as basic ground for oxidative damage. The aim of this study was to disclose whether the flow cytometric sorting procedure increases the production of reactive oxygen species (ROS), and to identify if ROS production relates to DNA damage in sorted spermatozoa using specific flow cytometry‐based assays. After sorting, oxidative stress increased from 26% to 33% in pre‐ and post‐incubation controls, to 46% after sex sorting (p < 0.05). Proportions of DNA fragmentation index post‐sorting were approximately 10% higher (31.3%); an effect apparently conduced via oxidative DNA damage as revealed by the oxyDNA assay. The probable origin of this increased oxidative stress owes the removal of enough seminal plasma due to the unphysiological sperm extension, alongside a deleterious effect of high pressure on mitochondria during the sorting procedure. 相似文献
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Semen of an infertile Dutch White (Saanenthal) goat buck was examined. Light and electron microscopic examinations showed aberrations of the sperm tails resembling the so-called Dag or Dag-like defects described in several cattle breeds. Ejaculated semen showed that virtually all of the cells had strongly coiled or broken tails, or fractured midpieces. Ultrastructural investigations by transmission electron microscopy (TEM) showed uneven distribution of the mitochondria in the midpiece. Coiled tails were encapsulated by a common membrane, and dislocated axial fibres and different membranous structures were also present. The ultrastructural characteristics of the defective sperm tails, the missing parts of the axial fibre bundle and the misalignment of the mitochondria indicate that this first case reported in goat is similar to the Dag-like defect in cattle. 相似文献
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Cristina Algieri Olga Blanco-Prieto Marc Llavanera Marc Yeste Marcella Spinaci Gaetano Mari Diego Bucci Salvatore Nesci 《Reproduction in domestic animals》2023,58(1):184-188
This study evaluated the bioenergetic map of mitochondria metabolism in cryopreserved bovine sperm. The detected oligomycin-sensitive basal respiration supported ATP production; frozen–thawed spermatozoa were found to have a coupling efficiency higher than 0.80. Cell respiration, however, was not stimulated by the protonophoric action of FCCP, as its titration with 1, 2, 4 and 6 μM did not stimulate the uncoupling activity on oxidative phosphorylation as highlighted by unresponsive oxygen consumption. The unusual effect on the stimulation of maximal respiration was not related to fibronectin- or PDL-coated plates used for cellular metabolism analysis. Conversely, irradiation of frozen–thawed bovine sperm with the red light improved mitochondrial parameters. In effect, the maximal respiration of red-light-stimulated sperm in PDL-coated plates was higher than the non-irradiated. In spite of this, red-light irradiation had no impact on membrane integrity and mitochondrial activity evaluated by epifluorescence microscopy. 相似文献
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Determination of the relationship between sperm morphologic classifications and fertility in stallions: 66 cases (1987-1988) 总被引：1，自引：0，他引：1
D J Jasko D H Lein R H Foote 《Journal of the American Veterinary Medical Association》1990,197(3):389-394
The analysis of breeding records and sperm morphologic classifications from ejaculated semen during 99 stallion seasons, over a 2-year period, revealed a significant correlation (r = 0.34, P less than 0.01) between the percentage of morphologically normal sperm in ejaculates and the per cycle fertility estimate of the stallions studied. In addition, the percentage of sperm classified as having major defects (abnormal heads, proximal droplets, and abnormal midpieces) was significantly inversely correlated (r = -0.36, P less than 0.01) with the same fertility estimates. Multiple variable regression demonstrated that the variation in 2 morphologic features classified as major defects, abnormal heads, and proximal droplets, accounted for the largest amount of variation in fertility. It appears that in stallions, a large percentage of ejaculated sperm with major defects or other defects in combination with major defects is associated with a larger reduction in fertility than is associated with other defects. 相似文献
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Classically, evaluation of the breeding stallion for reduced fertility has relied on physical examination of the reproductive system, as well as evaluation of sperm number, motility, and morphology. Over the past 20 years, a number of other diagnostic methods have become available to facilitate reproductive evaluation of the stallion. Specifically, ultrasound imaging has provided much-improved diagnostic methods for evaluation of the external and internal genitalia of the stallion, and these methods have now become routine in evaluation of the stallion. Biochemical analyses of semen can provide useful information for diagnosis of azoospermia (determination of alkaline phosphatase), detection of urine contamination, or changes in pH. Numerous sperm function assays provide information concerning subcellular compartments of the sperm including the plasma membrane, DNA, acrosome, and mitochondria. Data correlating these functional assays with fertility in the stallion are limited in most cases, with the exception of the sperm chromatin structure assay. Finally, the recent sequencing of the equine genome offers the possibility of both marker-assisted selection for fertility traits and more specific information about genetic mutations that may be associated with differing levels of fertility in the stallion. 相似文献
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Rota A Manuali E Caire S Appino S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(1):123-125
This paper describes the case of a 2-year-old English Bulldog with severe teratozoospermia that consisted mainly of "Dag-like" defects, which is strong coiling of the tail. Although libido, semen volume and sperm concentration were normal, sperm motility was 5.0%, and 93.3% of spermatozoa exhibited morphological abnormalities affecting the tail. Transmission electron microscopic examination of the spermatozoa revealed strong folding, coiling and fracture of sperm midpieces and tails, axonemal defects and the presence of swollen and unevenly distributed mitochondria. Taking into account the dog's history and examinations and the constantly high percentage of abnormal spermatozoa over time, the defect was considered to be genetic in origin. 相似文献