Dynamics and necessity of SIRT1 for maternal-zygotic transition.

Dynamic changes in maternal‒zygotic transition (MZT) require complex regulation of zygote formation, maternal transcript decay, embryonic genome activation (EGA), and cell cycle progression. Although these changes are well described, some key regulatory factors are still elusive. Sirtuin-1 (SIRT1), an NAD-dependent histone deacetylase, is a versatile driver of MZT via its epigenetic and nonepigenetic substrates.

Male SIRT1 insufficiency leads to sperm with decreased ability to hyperactivate and fertilize.

Deficient sperm motility is a frequent cause of the age-related male sub-/infertility. Since the protein sirtuin 1 (SIRT1) develops anti-aging action and participates in sperm motility and ATP synthesis in mitochondria, we investigated its role in the acquisition of hyperactivated motility during capacitation. For this, the dynamics of sperm subpopulations were studied, using males of Sirt1 heterozygous mutant mice.

Unravelling how in vitro capacitation alters ram sperm chromatin before and after cryopreservation.

Background: Sperm chromatin structure provides valuable information for the prediction of male fertility and can be altered during different procedures. Previous studies have shown that sperm chromatin condensation decreased during in vitro capacitation. Moreover, cryopreservation can affect sperm DNA integrity and chromatin compaction.

Beneficial Effects of Melatonin in the Ovarian Transport Medium on In Vitro Embryo Production of Iberian Red Deer ().

A major limiting factor for the development of in vitro embryo production (IVP) in wild species, such as Iberian red deer, compared to livestock animals is the poor availability and limited access to biological material. Thus, the use of post-mortem ovaries from slaughtered animals represent a source of oocytes for the large scale production of embryos needed for research and to improve the efficiency of IVP. However, these oocytes are not as developmentally competent as their in vivo counterparts.

Sperm Cryodamage in Ruminants: Understanding the Molecular Changes Induced by the Cryopreservation Process to Optimize Sperm Quality.

Sperm cryopreservation represents a powerful tool for livestock breeding. Several efforts have been made to improve the efficiency of sperm cryopreservation in different ruminant species. However, a significant amount of sperm still suffers considerable cryodamage, which may affect sperm quality and fertility.

Optimization of Sperm Cryopreservation Protocol for Peregrine Falcon ().

Sperm cryopreservation is a complex process that needs to be adapted to wild and domestic avian species to ensure proper efficiency. Because of its accessibility, the peregrine falcon may be used as a good model for studying other raptor species. To find the most optimal cryopreservation protocol for peregrine falcon ejaculates, sperm parameters such as motility, viability, DNA fragmentation, acrosome integrity, and mitochondrial activity were analyzed under different conditions by varying the freezing method (slow freezing in straws vs.

Cryopreservation of ram sperm alters the dynamic changes associated with in vitro capacitation.

The aim of this study was to investigate the dynamic changes that ram sperm experience during in vitro capacitation before and after cryopreservation. Using flow cytometry and computer assisted sperm analysis system (CASA), protein tyrosine phosphorylation and several functional parameters were evaluated in fresh and cryopreserved ram sperm incubated under capacitating and non-capacitating conditions at 0, 1, 5, 15, 30, 60, 120, 180 and 240 min. A short incubation period (5-30 min) under capacitating conditions was enough to increase mitochondrial activity and tyrosine phosphorylation in cryopreserved sperm, inducing also changes in the motility pattern, which could be related to hyperactivation.

Oxygen tension during in vitro oocyte maturation and fertilization affects embryo quality in sheep and deer.

Incubation gas atmosphere affects the development of in vitro produced embryos. In this study, there was examination of effects of two different oxygen (O) tensions (5 % and 21 %) during in vitro maturation (M5 and M21) and/or fertilization (F5 and F21) on embryo production and quality in deer and sheep. There was assessment of the percentage of embryos with cell cleavage occurring, percentage that developed to the blastocyst stage, and analysis of the relative abundance of mRNA transcript for genes important for development to the blastocyst stage.

Recombinant SPINK3 improves ram sperm quality and in vitro fertility after cryopreservation.

Capacitation-like changes affect sperm of several species, such as ram, reducing cell survival and fertilizing competence. Proteins from seminal plasma stabilize sperm plasma membranes, being an interesting focus to develop strategies for improving cryopreserved ram semen performance. To date, biotechnologies are focused to reduce damage in frozen-thawed ram spermatozoa through the addition of bioactives.

Comparative evaluation of DNA integrity using sperm chromatin structure assay and Sperm-Ovis-Halomax during in vitro capacitation of cryopreserved ram spermatozoa.

This study aimed to compare the ability of sperm chromatin structure assay (SCSA ) and Sperm-Ovis-Halomax to detect DNA fragmentation in frozen-thawed ram spermatozoa incubated under capacitating conditions in synthetic oviductal fluid (SOF) supplemented with oestrous sheep serum (SOF-ESS) at multiple time points (0-240 min). Incubation in SOF-ESS had no significant effects on SCSA parameters while the percentage of spermatozoa with fragmented DNA measured by Sperm-Ovis-Halomax increased after 180 min of incubation. In addition, no correlation or agreement was found between the techniques, suggesting that SCSA and Sperm-Ovis-Halomax may quantify different types of DNA damage in ram spermatozoa under these experimental conditions.

Freezing-Thawing Procedures Remodel the Proteome of Ram Sperm before and after In Vitro Capacitation.

Mammalian sperm must undergo a set of structural and functional changes collectively termed as capacitation to ensure a successful oocyte fertilization. However, capacitation can be compromised by cryopreservation procedures, which alter the proteome and longevity of sperm. To date, how the protein changes induced by cryopreservation could affect the acquisition of sperm fertilizing potential remains unexplored.

Effects of vitrification on ram spermatozoa using free-egg yolk extenders.

The present study aimed to examine the behavior of ram spermatozoa subjected to a vitrification process in free-egg yolk diluents in relation with conventional diluents and cryopreservation protocol used in this species. Previously it was investigated the toxicity of cryoprotectants, sucrose and glycerol, based on different concentrations (sucrose at 0.03 M, 0.