Extender supplementation with catalase maintains the integrity of sperm plasma membrane after freezing–thawing of semen from capuchin monkey

Best practices for cryopreserving sperm in Nonhuman Primates: a systematic review and meta-analysis

Nonhuman primates (NHPs) are in increasing demand as models for preclinical research. The availability of a highly efficient cryopreservation protocol for use with NHP sperm has potential to significantly alleviate this demand and contribute to rapid increases in overall number of NHPs available for biomedical research. Thus, this systematic review assesses the state-of-the-art in NHP sperm cryopreservation and uses meta-analyses to describe the impact of varied cryopreservation approaches on NHP sperm. We searched the literature deposited in PubMed, Scopus, and Web of Science databases through June 2024 to identify data relevant to the effect of sperm cryopreservation on quality of thawed sperm compared to fresh sperm across NHP species. All original NHP studies reporting sperm parameters both before cryopreservation and after thawing were included for analysis. In total, 32 articles were included for qualitative analysis and not surprisingly, all 32 studies demonstrated negative effects of cryopreservation on sperm parameters, Specifically, motility and viability were significantly decreased in thawed NHP sperm. While the method of sperm collection did not have a significant impact on recovery of motile sperm, significant variability was evident between species. Importantly, recovery of motile NHP sperm was greatest following rapid sperm freezing methods. This analysis provides critical insights into future research directions to enhance and optimize cryopreservation protocols in NHPs.

Reproductive biology of owl (Aotus spp.) and capuchin (Sapajus spp.) monkeys

Studies related to morpho-physiology improve the understanding of biological mechanisms in non-human primates (NHP), contributing to research in several areas, especially those of assisted reproduction and biomedicine. The genera Aotus and Sapajus are important considerations in conducting studies related to reproductive biology and biomedical research, where animals of these genera can serve as models for species with vulnerable conservation status. The reproductive functions of animals of these genera can be used in conducting studies with other NHP species, for which biological material is difficult to access. The aim in conducting the current review was to compile the scientific literature on the biology and reproductive aspects of these two genera, to provide a for a greater understanding of these topics. In addition, a systematic review of literature allows for efficient access relevant information from an extended timeframe collated in a single document. There was, therefore, a systematic search for keywords based on reproductive studies with animals in these genera conducted, and 58 articles, 12 books, and three academic theses were subsequently selected. Even though there have been advances in knowledge of the reproductive biology of animals from these genera that have occurred in recent decades, especially research conducted when these NHP were in captivity, a wide variety of areas remain to be studied so that the understanding of reproduction in these NHP can be enhanced and the knowledge gained from these studies utilized for greater understanding of reproduction of NHP in general.

Extender Supplementation with Antioxidants Selected after the Evaluation of Sperm Susceptibility to Oxidative Challenges in Goats

This study aimed to detect the most deleterious ROS for goat sperm and then supplemented the extender with a proper antioxidant. For this, 12 adult goats (aged 1-7) were used. Fresh samples were submitted to challenge with different ROS (superoxide anion, hydrogen peroxide, and hydroxyl radical) and malondialdehyde (MDA-toxic product of lipid peroxidation). After experiment 1, sperms were cryopreserved in extenders supplemented to glutathione peroxidase (Control: 0 UI/mL; GPx1: 1 UI/mL; GPx5: 5 UI/mL, and GPx10: 10 UI/mL) and catalase (Control: 0 UI/mL; CAT60: 60 UI/mL; CAT120: 120 UI/mL, and CAT240: 240 UI/mL). Each sample was evaluated by motility, plasma membrane integrity (eosin/nigrosin), acrosome integrity (fast green/rose bengal), sperm morphology, assay of the sperm chromatin structure, mitochondrial activity (3,3-diaminobenzidine), and measurement of lipid peroxidation (thiobarbituric acid reactive substances [TBARS]). It was possible to observe a mitochondrial dysfunction (DAB-Class IV) and low membrane integrity after hydrogen peroxide action. However, the high rates of TBARS were observed on hydroxyl radical. CAT240 presents the lower percentage of plasma membrane integrity. It was possible to attest that hydrogen peroxide and hydroxyl radical are the more harmful for goat sperm. Antioxidant therapy must be improving perhaps using combination between antioxidants.