Gene dysregulation impairs placental angiogenesis in allogeneic pig pregnancies.

Embryo transfer (ET) is a valuable reproductive technology in pigs, albeit its efficiency remains significantly lower than that of natural mating or artificial insemination (AI), owing to high embryonic death rates. Critical for embryo survival and pregnancy success is the placenta, which supports conceptus development through nutrient exchange, hormone production, and immune modulation. Alterations in placental development and function may therefore underlie the reduced efficiency of ET.

Could Individual Variability in Resistance to Cryopreservation ("Freezability") Serve as a Biomarker Reflecting Boar Fertility?

Subfertile boars often go undetected until they cause significant reproductive losses. Current semen quality assessments are limited in their ability to predict fertility, highlighting the need for complementary biomarkers. This study explored whether semen freezability could serve as an indirect indicator of boar fertility.

Presence and Location of CatSper 1-4, Opioid (μ, δ and κ) and CD44 Receptors in SPERMATOZOA from AOUDAD, IBERIAN IBEX and Mouflon.

Despite the apparent progress in reproductive technologies in wild ruminant species, healthy live births have been limited. Acquiring a sound knowledge of the molecular basis of most functional aspects of spermatozoa will improve the effectiveness of reproductive techniques and optimise conservation programs for threatened species. CatSper channels, opioid receptors and CD44 are involved in sperm capacitation of humans and domestic animals, but their presence in wild ruminants is yet undisclosed.

Molecular Mechanisms Involved in Sperm Development, Maturation, and Fertilization.

The journey of the spermatozoon, from its formation in the testis to its fusion with the oocyte, is a process carefully regulated by an intricate network of molecular mechanisms [...

Spermatology: Current Methods to Study Sperm Classical Variables.

It was back in 1677 when most researchers agreed that spermatology started, supported by van Leeuwenhoek's report about sperm discovery when demonstrating his novel microscope. Since then, multiple approaches have been applied to elucidate key aspects of the morphology of the male gamete and whether they would prognose fertility. Curiosity advanced in parallel with the many analytical tools, including the currently highlighted omics, which opened a yet unexplored scenario where researchers are worldwide trying to describe in detail not only the structure but also the mechanism behind sperm function.

Effect of Capacitation on Proteomic Profile and Mitochondrial Parameters of Spermatozoa in Bulls.

Sperm capacitation is a critical process for fertilization. This work aims to analyze the effect capacitation had on the proteome and mitochondrial parameters of bull spermatozoa. Viability, mitochondrial membrane potential (MMP), and reactive oxygen species (mROS) were assessed by flow cytometry in noncapacitated (NC) and capacitated (IVC) sperm.

Protective effect of supplementation with water soluble β-carotene and α-tocopherol in boar sperm cooling-freezing extender, but not in the thawing extender.

Cryopreservation of sperm is a crucial tool for the long-term preservation of male genetic material, causing significant issues in motility, membrane, and acrosome integrity, among other parameters. Antioxidants have been used to cope with these detrimental effects. We tested 1.

Effect of Semen Collection in the Metabolite and Hormonal Content of Rabbit Seminal Plasma.

Blood serum (BS) and seminal plasma (SP) share a plethora of compounds that might present an individual and/or temporal concentration variation. We aimed to determine whether BS and SP concentrations of albumin, calcium, citrate, creatinine, fructose, glucose, lactate, total protein, urea, zinc, cortisol, anti-Müllerian hormone (AMH) and testosterone are related to weekly collections in New Zealand White (NZW) adult rabbit bucks. During a 12-week study, blood samples were obtained at the beginning and the end of the study period, and semen samples were taken twice a week from four NZW adult rabbit bucks, starting at 6-7 months of age.

Bovine serum albumin inclusion in the thawing extender improves boar sperm membrane and acrosomal integrity.

This study investigates the impact of bovine serum albumin (BSA) inclusion in the thawing extender on boar sperm quality. Thawing protocols in sperm cryopreservation are vital, yet underexplored. It has been determined that BSA can interact with membranes, stabilizing them and preventing damage during the freezing process, for this reason it could also have a beneficial effect during thawing.

Effect of the addition of exogenous progesterone and the progesterone receptor inhibitor (RU 486) on boar cryopreservation semen extenders.

Cryopreservation of porcine spermatozoa is detrimental due to their high sensitivity to cold shock, leading to changes akin to capacitation, known as cryocapacitation. These changes, including the acrosomal reaction, hypermotility induction, and protein phosphorylation, might be influenced by the presence of progesterone in seminal plasma and egg yolk, used in most freezing extenders. We tested the effect of various progesterone concentrations added to the freezing extenders (1, 10, and 100 μg/mL).

Cooling rate modifies the location of aquaporin 3 in spermatozoa of sheep and goat.

The freeze-thawing process induces osmotic changes that may affect the membrane domain location of aquaporins' (AQP) in spermatozoa. Recent studies suggest that changes in AQP3 localization allows better sperm osmo-adaptation, improving the cryoresistance. Ultra-rapid freezing is an alternative cryopreservation technique that requires less equipment than conventional freezing, and it is faster, simpler and can be used in the field.

Evaluation of Different Thawing Protocols on Iberian Boar Sperm Preserved for 10 Years at Different Liquid Nitrogen Levels.

The conservation of genetic resources in pig breeds, notably the Iberian pig, is crucial for genetic improvement and sustainable production. Prolonged storage in liquid nitrogen (LN) is recognized for preserving genetic diversity, but potential adverse effects on seminal quality remain debated. This study aims to assess the impact of ten years of storage at different LN levels and to optimize thawing protocols for Iberian pig sperm.

Application of Flow Cytometry Using Advanced Chromatin Analyses for Assessing Changes in Sperm Structure and DNA Integrity in a Porcine Model.

Chromatin status is critical for sperm fertility and reflects spermatogenic success. We tested a multivariate approach for studying pig sperm chromatin structure to capture its complexity with a set of quick and simple techniques, going beyond the usual assessment of DNA damage. Sperm doses from 36 boars (3 ejaculates/boar) were stored at 17 °C and analyzed on days 0 and 11.

MicroRNA expression in specific segments of the pig periovulatory internal genital tract is differentially regulated by semen or by seminal plasma.

microRNAs play pivotal roles during mammalian reproduction, including the cross-talk between gametes, embryos and the maternal genital tract. Mating induces changes in the expression of mRNA transcripts in the female, but whether miRNAs are involved remains to be elucidated. In the current study, we mapped 181 miRNAs in the porcine peri-ovulatory female reproductive tract: Cervix (Cvx), distal and proximal uterus (Dist-Ut, Prox-Ut), Utero-tubal-junction (UTJ), isthmus (Isth), ampulla (Amp), and infundibulum (Inf) when exposed to semen (natural mating (NM) or artificial insemination (AI-P1)) or to infusions of sperm-free seminal plasma (SP): the first 10 mL of the sperm rich fraction (SP-P1) or the entire ejaculate (SP-E).

Immunolocalisation of aquaporins 3, 7, 9 and 10 in the epididymis of three wild ruminant species (Iberian ibex, mouflon and chamois) and sperm cryoresistance.

Context: In the epididymis, epithelial cells manage changes in the luminal environment for proper sperm maturation. Moreover, aquaglyceroporins, a subgroup of aquaporins (AQP), modulate the transport of water, glycerol and other small molecules in epithelial cells.

Aims: We aim to characterise the lining epithelium, quantify its cell composition and immunolocalise the aquaglyceroporins AQP3, AQP7, AQP9 and AQP10 alongside the epididymal ductus of three wild ruminant species, and to determine if species-specific differences could be associated with cauda sperm cryoresistance variations.

Bicarbonate and BSA increase the capacitation pattern and acrosomal exocytosis in boar sperm after 120 min of incubation.

Sperm capacitation is a crucial step towards the acquisition of fertilizing capacity. Despite the attempts to mimic the in vivo situation, there is still a lack of standardization in vitro techniques. Bicarbonate and serum albumin (BSA) are routinely used, although controversial results are reported regarding the optimal concentration of each compound.

Pre-freezing selection of Holstein bull semen with the BoviPure colloid as double- or single-layer centrifugation improves the post-thawing quality.

Artificial insemination (AI) is critical for breeding in the dairy industry. High-merit bulls can present low freezability, hampering genetic dissemination. Thawed semen can be improved using density gradient centrifugation (DGC) with colloids, but little information deals with the pre-freezing application.

The Cation/Calcium Channel of Sperm (CatSper): A Common Role Played Despite Inter-Species Variation?

The main cation/calcium channel of spermatozoa (CatSper), first identified in 2001, has been thoroughly studied to elucidate its composition and function, while its distribution among species and sperm sources is yet incomplete. CatSper is composed of several subunits that build a pore-forming calcium channel, mainly activated in vivo in ejaculated sperm cells by intracellular alkalinization and progesterone, as suggested by the in vitro examinations. The CatSper channel relevance is dual: to maintain sperm homeostasis (alongside the plethora of membrane channels present) as well as being involved in pre-fertilization events, such as sperm capacitation, hyperactivation of sperm motility and the acrosome reaction, with remarkable species differences.

Effect of Honey, Coenzyme Q10, and β-Carotene/α-Tocopherol as Novel Additives in Rabbit-Sperm Cryopreservation Extender.

The effectiveness of rabbit-sperm cryopreservation is still below average compared to other domestic species. After the sperm cryopreservation process, post-thawing parameters like motility and membrane integrity are significantly compromised. The use of new extender constituents is an approach that can be used to improve the effectiveness of cryopreservation.

Mating modifies the expression of crucial oxidative-reductive transcripts in the pig oviductal sperm reservoir: is the female ensuring sperm survival?

Background: Mating induces large changes in the female genital tract, warranting female homeostasis and immune preparation for pregnancy, including the preservation of crucial oxidative status among its pathways. Being highly susceptible to oxidative stress, sperm survival and preserved function depend on the seminal plasma, a protection that is removed during sperm handling but also after mating when spermatozoa enter the oviduct. Therefore, it is pertinent to consider that the female sperm reservoir takes up this protection, providing a suitable environment for sperm viability.

Variation of existence and location of aquaporin 3 in relation to cryoresistance of ram spermatozoa.

Introduction And Objective: Osmotic changes during the process of freeze-thawing involve changes in the location of aquaporins (AQPs) in membrane domains of spermatozoa. Some AQPs, like aquaporin 3 (AQP3), are linked to sperm cryotolerance in the porcine species. Conspicuous individual variability exists between rams and their ejaculates, which may be classified as displaying good freezability (GFE) or poor freezability (PFE), depending on several endogenous and environmental factors.