A conserved role of the Hippo signalling pathway in initiation of the first lineage specification event across mammals.

Our understanding of the molecular events driving cell specification in early mammalian development relies mainly on mouse studies, and it remains unclear whether these mechanisms are conserved across mammals, including humans. We have shown that the establishment of cell polarity via aPKC is a conserved event in the initiation of the trophectoderm (TE) placental programme in mouse, cow and human embryos. However, the mechanisms transducing cell polarity into cell fate in cow and human embryos are unknown.

PRD-Class Homeobox Genes in Bovine Early Embryos: Function, Evolution, and Overlapping Roles.

Eutherian Totipotent Cell Homeobox (ETCHbox) genes are mammalian-specific PRD-class homeobox genes with conserved expression in the preimplantation embryo but fast-evolving and highly divergent sequences. Here, we exploit an ectopic expression approach to examine the role of bovine ETCHbox genes and show that ARGFX and LEUTX homeodomain proteins upregulate genes normally expressed in the blastocyst; the identities of the regulated genes suggest that, in vivo, the ETCHbox genes play a role in coordinating the physical formation of the blastocyst structure. Both genes also downregulate genes expressed earlier during development and genes associated with an undifferentiated cell state, possibly via the JAK/STAT pathway.

Alpha-Lipoic Acid Can Overcome The Reduced Developmental Competency Induced by Alcohol Toxicity during Ovine Oocyte Maturation.

Objective: Alpha-lipoic acid (ALA) as a strong antioxidant has a protective effect. This study was designed to assess whether supplementation of maturation medium with ALA during maturation (IVM) can attenuate the toxic effect of ethanol.

Materials And Methods: In this experimental study, to assess the antioxidant capacity of ALA challenged by 1% ethanol during maturation, immature ovine oocytes were exposed to 1% alcohol in the presence or absence of 25 μM ALA during oocyte maturation.

Steroid regulation of secreted phosphoprotein 1 (SPP1) expression in ovine endometrium.

Secreted phosphoprotein 1 (SPP1) is an extracellular matrix glycoprotein that is highly expressed at the maternal-fetal interface and is a critical mediator of embryo implantation. The objectives of this study were to examine the spatial and temporal cyclical expression patterns and steroid regulation of SPP1 mRNA and protein in ovine endometrium, which may be further indicative of their functionality in embryo implantation. Uterine tissue was obtained following hysterectomy from ovariectomised ewes treated with ovarian steroids.

Sperm binding to hyaluronan is an excellent predictor of Nili-Ravi buffalo bull fertility.

This study reports the first evaluation of sperm hyaluronan binding assay (HBA) for predicting the fertility of Nili-Ravi buffalo bulls in relation to standard parameters of sperm quality. Cryopreserved semen doses of low (n = 6), medium (n = 3) and high fertility (n = 8) bulls based on their respective return rates were used. Significantly, more spermatozoa bound to hyaluronan from the most fertile bulls (57.

Initiation of a conserved trophectoderm program in human, cow and mouse embryos.

Current understandings of cell specification in early mammalian pre-implantation development are based mainly on mouse studies. The first lineage differentiation event occurs at the morula stage, with outer cells initiating a trophectoderm (TE) placental progenitor program. The inner cell mass arises from inner cells during subsequent developmental stages and comprises precursor cells of the embryo proper and yolk sac.

Polyunsaturated fatty acids influence offspring sex ratio in cows.

Dietary polyunsaturated fatty acids (PUFAs) can influence fertility in farm animals. Some evidence in mice and sheep have suggested that PUFAs may influence offspring sex ratio, which may have significant value for cattle production. To test this hypothesis, three groups of Holstein cows were supplemented with either 0%, 3% or 5% protected fat (PF) in the form of calcium salt of fatty acids (rich in omega-6) from 14-21 days pre-partum until conception.

Effect of horse sex status on British Eventing competition performance: an observational study between 1998 and 2016.

To test the hypothesis that gender affects horse scores in eventing competition, data on the scores and points awarded to 681 horses was collected from the British Eventing website. Equal numbers of mares, geldings and stallions were used, all foaled during or after 1994 and aged 4-10 years. The study included five levels of competition (BE90, BE100, Novice, Intermediate and Advanced) and investigated differences in mean phased scores, total scores and rank in competition.

Effect of melatonin supplementation in the long-term preservation of the sheep ovaries at different temperatures and subsequent in vitro embryo production.

Investigations in the past decades have shown that oocytes developmental competence following in vitro fertilization is greatly influenced by an interval between isolation of the ovaries immediately after death/slaughter and oocytes recovery from the visible follicles. In order to determine the optimal conditions for long-term preservation of ovaries, an experiment was conducted with adding different doses of melatonin (0 (C), 500 (M1), 600 (M2), 700 (M3) and 800 (M4) μM) as an antioxidant to sheep ovaries preservation medium (PBS) maintained at 4 and 20 °C for 24 h. The effects on in vitro embryo production (IVEP) parameters including maturation, fertilization, cleavage, and blastocyst rates and the total number of blastomere were evaluated after the ovaries preservation.

Differential proteomic profiling of endometrium and plasma indicate the importance of hydrolysis in bovine endometritis.

Endometritis is an important disease of dairy cows that leads to significant economic losses in the dairy cattle industry. To investigate the alteration of proteins associated with endometritis in the dairy cow, the isobaric tags for relative and absolute quantification (iTRAQ) technique was applied to quantitatively identify differentially expressed proteins (DEP) in the endometrium and peripheral plasma of Chinese Holstein cows with endometritis. Compared with the normal (control) group, 159 DEP in the endometrium and 137 DEP in the plasma were identified in cows with endometritis.

Linoleic (LA) and linolenic (ALA) acid concentrations in follicular fluid of prepubertal goats and their effect on oocyte in vitro maturation and embryo development.

In this study we assessed the concentration of linoleic acid (LA) and linolenic acid (ALA) in follicular fluid of prepubertal goats according to follicle size (<3mm or ≥3mm) by gas chromatography and tested the addition of different LA and ALA (LA:ALA) concentration ratios (50:50, 100:50 and 200:50µM) to the IVM medium on embryo development, mitochondrial activity, ATP concentration and relative gene expression (RPL19, ribosomal protein L19; SLC2A1, facilitated glucose transporter 1; ATF4, activating transcription factor 4; GPX1, glutathione peroxidase 1; HSPA5, heat-shock protein family A 70 kDa; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; DNMT1, DNA methyltransferase 1; GCLC, glutamate-cysteine ligase catalytic subunit; SOD1, superoxide dismutase 1). Oocytes were in vitro matured, fertilised or parthenogenetically activated and zygotes were cultured following conventional protocols. LA concentration ranged from 247 to 319µM and ALA concentration from 8.

Beneficial effects of melatonin on in vitro embryo production from juvenile goat oocytes.

Melatonin is a universal antioxidant that improves in vitro embryo production in several species. The aims of this study were to determine the melatonin concentration in the ovarian follicular fluid (FF) of juvenile goats and the effect of melatonin during in vitro maturation (IVM) on embryo development. The FF melatonin concentration was 0.

Regulation and roles of the hyaluronan system in mammalian reproduction.

Hyaluronan (HA) is a non-sulphated glycosaminoglycan polymer naturally occurring in many tissues and fluids of mammals, including the reproductive system. Its biosynthesis by HA synthase (HAS1-3) and catabolism by hyaluronidases (HYALs) are affected by ovarian steroid hormones. Depending upon its molecular size, HA functions both as a structural component of tissues in the form of high-molecular-weight HA or as a signalling molecule in the form of small HA molecules or HA fragments with effects mediated through interaction with its specific cell-membrane receptors.

Influence of hyaluronan on endometrial receptivity and embryo attachment in sheep.

An increasing number of reports suggests a role of hyaluronan (HA) in female reproduction and interest in its application in assisted reproduction is rising. However, there are contrasting data about the effectiveness of adding HA to the embryo-transfer medium on improving pregnancy rates. Using sheep as an experimental model, the studies reported here analysed the impact of HA infusion into the uterus on embryo attachment to uterine luminal epithelium (LE) and expression of selected markers of uterine receptivity.

Hyaluronan and hyaluronidase, which is better for embryo development?

Our aim was to examine size-specific effects of Hyaluronan (HA) on preimplantation embryo development. We investigated the effects of Hyalovet (HA, 500-750 kDa; the size produced by HA synthase-3, which is abundant in the oviduct), or HA treated with Hyaluronidase-2 (Hyal2; also expressed in the oviduct that breaks down HA into 20 kDa fragments). In experiment 1 (in vivo), oviducts of synchronized and superovulated ewes (n = 20) were surgically exposed on Day 2 post-mating, ligated, and infused with either Hyalovet, Hyalovet + Hyal2, Hyal2, or PBS (control).

In vivo and in vitro studies of MUC1 regulation in sheep endometrium.

In this study, we investigated the expression of mucin 1 (MUC1) mRNA and protein in sheep endometrium at different time points during follicular and luteal phases of estrous cycle, and also determined the effect of steroid hormone treatments and interferon tau (IFNτ) on MUC1 mRNA expression in endometrial cell culture in vitro. In experiment one, 15 Welsh mountain ewes were synchronized to a common estrus and killed at precise stages of estrous cycle corresponding to (1) pre-LH peak, (2) LH peak, (3) post-LH peak, (4) early luteal, and (5) mid-luteal. Reproductive tracts were harvested and mRNA was extracted from the endometrial tissues.

Effects of dietary supplementation of pioglitazone on metabolism, milk yield, and reproductive performance in transition dairy cows.

The objective of this study was to investigate the effect of dietary supplementation of pioglitazone (PGT), a specific ligand for PPARγ, on metabolic dynamics, milk production, and reproductive performance of transition dairy cows. Eighty multiparous Holstein cows in their second or more lactations were blocked by the calving date and parity and assigned randomly to four dietary groups (n = 20 cow/treatment) including control (no PGT-/-), supplemented with PGT (6-mg PGT/kg body weight) from Day -14 to +21 relative to parturition (PGT+/+) or only during prepartum (PGT+/-) or postpartum periods (PGT-/+). Postpartum body condition score and body weight loss decreased (P < 0.

Global transcriptomic profiling of bovine endometrial immune response in vitro. II. Effect of bovine viral diarrhea virus on the endometrial response to lipopolysaccharide.

Infection with noncytopathic bovine viral diarrhea virus (ncpBVDV) is associated with uterine disease and infertility. This study investigated the influence of ncpBVDV on immune functions of the bovine endometrium by testing the response to bacterial lipopolysaccharide (LPS). Primary cultures of mixed epithelial and stromal cells were divided into four treatment groups (control [CONT], BVDV, CONT+LPS, and BVDV+LPS) and infected with ncpBVDV for 4 days followed by treatment with LPS for 6 h.

Global transcriptomic profiling of bovine endometrial immune response in vitro. I. Effect of lipopolysaccharide on innate immunity.

The dysregulation of endometrial immune response to bacterial lipopolysaccharide (LPS) has been implicated in uterine disease and infertility in the postpartum dairy cow, although the mechanisms are not clear. Here, we investigated whole-transcriptomic gene expression in primary cultures of mixed bovine epithelial and stromal endometrial cells. Cultures were exposed to LPS for 6 h, and cellular response was measured by bovine microarray.

Histochemical structure and immunolocalisation of the hyaluronan system in the dromedary oviduct.

We investigated the local modulation of some histochemical properties of oviducts of the dromedary (Camelus dromedarius), focusing on the immnolocalisation of hyaluronic acid (HA) synthases (HAS2 and HAS3), hyaluronidases (HYAL2 and HYAL1) and the HA receptor CD44 in the ampulla and isthmus. Abundant acidic mucopolysaccharides (glycosaminoglycans) were detected by Alcian blue staining along the luminal surface of both ciliated and non-ciliated epithelial cells (LE). Staining for HAS2 was higher in the primary epithelial folds of the ampulla compared with the isthmus, especially in secretory cells, adluminal epithelial surface and supranuclear cell domain.

Effect of α-linolenic acid on oocyte maturation and embryo development of prepubertal sheep oocytes.

The purpose of this study was to evaluate the effect of omega-3 α-linolenic acid (ALA) added to the IVM medium on embryo development of prepubertal sheep oocytes. Experiment 1 investigated the effect of ALA at different concentrations (0 [control], 50, 100, and 200 μM) and DMSO (100 μM) in IVM media on cumulus cell expansion and oocyte nuclear maturation and on synthesis of prostaglandins (PGE2 and PGF2α). Experiment 2 investigated the effects of ALA at different concentrations in the IVM medium on oocyte fertilization, cleavage, and developmental potential to blastocyst stage and changes in estradiol and progesterone concentrations in the spent IVM media.

Role of PTGS2-generated PGE2 during gonadotrophin-induced bovine oocyte maturation and cumulus cell expansion.

Prostaglandin E2 (PGE2) is an autocrine/paracrine factor which mediates gonadotrophin (Gn) stimulation of cumulus expansion and oocyte maturation in rodents. Its role in bovine oocyte maturation is less characterized. This study detected PTGS2 (COX2) and PGE synthases (PTGES1, PTGES2 and PTGES3) in bovine cumulus-oocyte complexes (COC).

Influence of caffeine pretreatment on biphasic in vitro maturation of dog oocytes.

Phosphodiesterase (PDE) inhibitors have been utilized for in vitro maturation (IVM) of oocytes to manipulate the meiotic resumption and progression. Premature chromatin condensation and DNA replication of the oocytes, immediately after the decrease in the cAMP level, are the difficulties in canine IVM. Caffeine, a nonselective competitive PDE inhibitor, due to its structural similarity to adenosine molecule maintains the cAMP level by occupying PDE enzymes such as PDE-3A inside the oocyte and PDE-4 and PDE-5 in the cumulus cells.

Regulation of the hyaluronan system in ovine endometrium by ovarian steroids.

In this study, we investigated steroid regulation of the hyaluronan (HA) system in ovine endometrium including HA synthases (HAS), hyaluronidases, and HA receptor-CD44 using 30 adult Welsh Mountain ewes. Eight ewes were kept intact and synchronized to estrous (day 0). Intact ewes were killed on day 9 (luteal phase; LUT; n=5) and day 16 (follicular phase; FOL; n=3).