Exposure to environmental contaminants and folic acid supplementation intergenerationally impact fetal skeleton development through the paternal lineage in a rat model.

Persistent organic pollutants (POPs) are ubiquitous in the environment, which is of concern since they are broadly toxic for wildlife and human health. It is generally accepted that maternal prenatal folic acid supplementation (FA) may beneficially impact offspring development, but it has been recently shown that the father's exposures also influence the health of his offspring. Bone is an endocrine organ essential for whole-body homeostasis and is susceptible to toxicants.

Mechanism of Action of an Environmentally Relevant Organochlorine Mixture in Repressing Steroid Hormone Biosynthesis in Leydig Cells.

Within Leydig cells, steroidogenesis is induced by the pituitary luteinizing hormone (LH). The binding of LH to its receptor increases cAMP production, which then activates the expression of genes involved in testosterone biosynthesis. One of these genes codes for the steroidogenic acute regulatory (STAR) protein.

Early-Life Exposure to Environmental Contaminants Perturbs the Sperm Epigenome and Induces Negative Pregnancy Outcomes for Three Generations via the Paternal Lineage.

Due to the grasshopper effect, the Arctic food chain in Canada is contaminated with persistent organic pollutants (POPs) of industrial origin, including polychlorinated biphenyls and organochlorine pesticides. Exposure to POPs may be a contributor to the greater incidence of poor fetal growth, placental abnormalities, stillbirths, congenital defects and shortened lifespan in the Inuit population compared to non-Aboriginal Canadians. Although maternal exposure to POPs is well established to harm pregnancy outcomes, paternal transmission of the effects of POPs is a possibility that has not been well investigated.

ACRBP (Sp32) is involved in priming sperm for the acrosome reaction and the binding of sperm to the zona pellucida in a porcine model.

In boar sperm, we have previously shown that capacitation is associated with the appearance of the p32 tyrosine phosphoprotein complex. The principal tyrosine phosphoprotein involved in this complex is the acrosin-binding protein (ACRBP), which regulates the autoconversion of proacrosin to intermediate forms of acrosin in both boar and mouse sperm. However, the complete biological role of ACRBP has not yet been elucidated.

Adipose Tissue Transcriptome Is Related to Pollutant Exposure in Polar Bear Mother-Cub Pairs from Svalbard, Norway.

Being at the food chain apex, polar bears () are highly contaminated with persistent organic pollutants (POPs). Females transfer POPs to their offspring through gestation and lactation; therefore, young cubs present higher POPs concentrations than their mothers. Recent studies suggest that POPs affect the lipid metabolism in female polar bears; however, the mechanisms and impact on their offspring remain unknown.

Beyond fertilisation: How the paternal environment influences future generations.

In light of the relatively ignored role of paternal influences on offspring development and increasing societal concerns regarding possible health consequences of chemical exposures, our team has addressed the overall hypothesis that environmentally-relevant levels of contaminants have long-lasting effects that are transmitted through the paternal lineage. This review focuses on our research examining the impact of developmental exposure to toxicants and nutrients on the phenotype and epigenome of the male and of his subsequent generations. This report is intended to encourage animal andrologists as well as the domestic animal production industry to increase their consideration of the sire's environment in the context of agricultural productivity.

Prenatal Exposure to Environmentally-Relevant Contaminants Perturbs Male Reproductive Parameters Across Multiple Generations that are Partially Protected by Folic Acid Supplementation.

The paternal environment is thought to influence sperm quality and future progeny may also be impacted. We hypothesized that prenatal exposure to environmentally-relevant contaminants impairs male reproduction, altering embryo gene expression over multiple generations. Folic acid (FA) can improve sperm quality and pregnancy outcomes, thus we further hypothesized that FA mitigates the contaminants.

Maternal folic acid supplementation does not counteract the deleterious impact of prenatal exposure to environmental pollutants on lipid homeostasis in male rat descendants.

Prenatal exposure to persistent organic pollutants (POPs) has been associated with the development of metabolic syndrome-related diseases in offspring. According to epidemiological studies, father's transmission of environmental effects in addition to mother's can influence offspring health. Moreover, maternal prenatal dietary folic acid (FA) may beneficially impact offspring health.

Customized MethylC-Capture Sequencing to Evaluate Variation in the Human Sperm DNA Methylome Representative of Altered Folate Metabolism.

Background: The sperm DNA methylation landscape is unique and critical for offspring health. If gamete-derived DNA methylation escapes reprograming in early embryos, epigenetic defects in sperm may be transmitted to the next generation. Current techniques to assess sperm DNA methylation show bias toward CpG-dense regions and do not target areas of dynamic methylation, those predicted to be environmentally sensitive and tunable regulatory elements.

Cell-lineage specificity of primary cilia during postnatal epididymal development.

Study Question: Where are primary cilia (PC) organelles located during postnatal epididymal development?

Summary Answer: Our findings unveil the existence of PC sensory organelles in different epididymal cell types according to postnatal development stage.

What Is Known Already: Primary cilia are sensory organelles that orchestrate major signaling pathways during organ development and homeostasis. Epididymal PC have been detected in the horses, donkey and mules but their cell-lineage specificity has never been investigated in this organ.

Histomorphologic Analysis of the Late-term Rat Fetus and Placenta.

Histological examination of the rat placenta and fetus is uncommon. Toxicological studies mainly rely on gross examination of the fetus and on fetal and placental weights. These are often insufficient to assess the fetal and placental toxicity of xenobiotics.

Novel technical strategies to optimize cryopreservation of goat semen using cholesterol-loaded cyclodextrin.

Artificial insemination is well-established in dairy cattle, with sires housed in commercial studs for processing. In some species, however, sires located on-farm are used for artificial insemination by shipping their semen to an off-site laboratory for processing within 24 h of collection. To expedite semen transport from the farm to laboratory, protocols must be uncomplicated.

Cholesterol-loaded cyclodextrin improves ram sperm cryoresistance in skim milk-extender.

Cholesterol-loaded cyclodextrin (CLC) is known to improve ram sperm cryosurvival. This study expands on previous research to: (1) determine the mechanism by which CLC improves ram sperm cryosurvival and (2) compare the efficiency of a novel, skim milk-based extender containing CLC to a traditional egg yolk-based extender. Hypothesis #1 was that CLC enhances membrane cholesterol content to increase the resistance of ram sperm to cold and osmotic stress, thereby improving cryosurvival.

Cholesterol-Loaded Cyclodextrin Increases the Cholesterol Content of Goat Sperm to Improve Cold and Osmotic Resistance and Maintain Sperm Function after Cryopreservation.

The success of semen cryopreservation depends on sperm membrane integrity and function after thawing. Cholesterol-loaded cyclodextrin (CLC) is used for in vitro incorporation of cholesterol to protect cells against cold temperatures. We hypothesized that CLC treatment also enhances sperm cholesterol content to increase tolerance to osmotic shock and cryoresistance, thereby improving fertility.

In boar sperm capacitation L-lactate and succinate, but not pyruvate and citrate, contribute to the mitochondrial membrane potential increase as monitored via safranine O fluorescence.

Having ascertained using JC-1 as a probe that, in distinction with the controls, during capacitation boar sperm maintains high mitochondrial membrane potential (ΔΨ), to gain some insight into the role of mitochondria in capacitation, we monitored ΔΨ generation due to externally added metabolites either in hypotonically-treated spermatozoa (HTS) or in intact cells by using safranine O as a probe. During capacitation, the addition to HTS of L-lactate and succinate but not those of pyruvate, citrate and ascorbate + TMPD resulted in increase of ΔΨ generation. Accordingly, the addition of L-lactate and succinate, but not that of citrate, to intact sperm resulted in ΔΨ generation increased in capacitation.

In vitro exposure of Leydig cells to an environmentally relevant mixture of organochlorines represses early steps of steroidogenesis.

Leydig cell steroidogenesis is mainly regulated by LH via increased cAMP production leading to STAR protein activation. STAR is essential for cholesterol shuttling inside mitochondria where steroidogenesis is initiated. Accumulating evidence suggest that persistent organochlorine compounds disrupt testicular function, but the mechanism of action remains poorly characterized.

Factors regulating sperm capacitation.

Capacitation is broadly defined as the functional modifications rendering sperm competent to fertilize, encompassing the ability of the sperm to bind the zona pellucida and subsequently undergo the acrosome reaction, hyperactivated motility, and the capacity to fuse with the oocyte. Although discovered in 1951, research over the past 15 years has considerably clarified the mechanisms leading to capacitation. The purpose of this review is to discuss the challenges of studying capacitation and to summarize recent notions regarding its regulation.

Cryopreservation affects bovine sperm intracellular parameters associated with capacitation and acrosome exocytosis.

Although semen cryopreservation is widely and commonly used in the bovine breeding industry, half the spermatozoa do not survive and most of those that do survive undergo numerous physiological changes that affect their fertilising ability. The aim of the present study was to determine how cryopreservation affects the intracellular events involved in sperm capacitation and acrosome reaction. Immediately after thawing and washing, almost 50% of spermatozoa were capacitated and more than 20% had lost their acrosome.

Modulation of bovine sperm signalling pathways: correlation between intracellular parameters and sperm capacitation and acrosome exocytosis.

In the present study, the viability, intracellular pH (pHi), cAMP ([cAMP]i), calcium concentration and protein phosphotyrosine content were evaluated in relation to the acrosomal and capacitation status of freshly ejaculated bull spermatozoa. These parameters were evaluated before and after incubation with the capacitation inducer heparin, the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX), the phosphotyrosyl-protein phosphatase inhibitors phenylarsine oxide (PAO) and sodium orthovanadate, and hydrogen peroxide. The results obtained were integrated to address the physiological interactions between the different signalling events affecting sperm capacitation and acrosome reaction.

Localization of Hsp60 and Grp78 in the human testis, epididymis and mature spermatozoa.

Molecular chaperones of the heat shock proteins (HSP) family are important in numerous cellular processes. In this study, the expression of Hsp60 and Grp78 proteins was investigated in the male reproductive tract. The cellular distribution of Hsp60 and Grp78 proteins was analysed in the human testis and epididymis by immunohistochemical approaches.

Effects of an environmentally relevant organochlorine mixture and a metabolized extract of this mixture on porcine sperm parameters in vitro.

Organochlorine chemicals are present in the environment worldwide; however, populations living in the Far North are particularly at risk because their traditional diets are mainly composed of contaminated animals (fish, seals, whales, and polar bears). It has been suggested that male fertility is globally declining, possibly because of chronic, low-level exposure to environmental contaminants. This study was designed to assess the effects on fresh sperm fertility parameters using the porcine model of 1) an environmentally relevant mixture of 15 organochlorines and 2) the metabolized extract of this mixture.

Cryopreservation of boar semen and its future importance to the industry.

Whereas AI has arguably been the most important management tool leading to improved herd productivity, long-term storage of semen brings forth additional advantages to producers of agriculturally important animals and the AI industry. Semen cryopreservation greatly facilitates the distribution of agriculturally desirable genes, rapidly increasing herd productivity. Of particular importance to the pig industry, the use of frozen semen would help to control transmission of certain pathogens, thereby protecting the health status of the herd.

An environmentally relevant mixture of organochlorines, their metabolites and effects on preimplantation development of porcine embryos.

Environmental exposure of human populations to organochlorines is still widespread despite several international regulations banning or restricting their use. This study tested the hypothesis that an environmentally relevant complex mixture of organochlorines comprising polychlorinated biphenyls (PCBs), technical chlordane, dichlorodiphenyldichloroethylene and 12 other components is toxic for porcine embryos (at relative concentrations of 1-10000-fold the environmental organochlorine levels of contamination or 4.2 microg/l total PCBs).

Impact of cryopreservation and reactive oxygen species on DNA integrity, lipid peroxidation, and functional parameters in ram sperm.

Assisted reproduction using frozen-thawed semen has practical advantages, although cryopreservation is detrimental to sperm fertility in most mammals. We examined the influence of cryopreservation and reactive oxygen species (ROS) on ram sperm DNA stability (using SCSA), lipid peroxidation (LPO), chlortetracycline fluorescence (CTC) patterns, motility and viability. In Experiment 1, DNA integrity, LPO, CTC, motility and viability tests were performed on fresh and cryopreserved sperm after 0, 6, and 24 hr in synthetic oviductal fluid (SOF).