Embryonic Death Research Articles

Inhibition of ferroptosis attenuate lipopolysaccharide-induced early pregnancy loss by protecting against decidual damage of stromal cells

Endometrial decidualization is critical for successful embryo implantation. Dysregulation of the immune microenvironment can disrupt normal decidualization processes, potentially resulting in early pregnancy loss. Ferroptosis, a form of cell death dependent on iron and lipid hydroperoxides, is closely associated with inflammation. In this study, we developed an inflammatory early pregnancy loss model to elucidate the mechanisms of decidual damage induced by lipopolysaccharide (LPS) and to assess whether ferroptosis contributes to LPS-induced early pregnancy loss. Through in vivo experiments, we observed that embryo implantation was significantly inhibited and endometrial decidualization was impaired during LPS-induced early pregnancy loss. LPS exposure resulted in abnormal mitochondrial morphology, reduced antioxidant capacity, accumulation of reactive oxygen species (ROS) and disruptions in iron metabolism during decidualization in mouse endometrial stromal cells (mESCs). The administration of ferroptosis inhibitors, specifically ferrostatin-1 (Fer-1) and deferoxamine (DFO), effectively reversed embryo loss and mitigated the decidual damage associated with LPS-induced early pregnancy loss. Fer-1 and DFO exhibited resistance to ferroptosis during decidualization by modulating the antioxidant system and iron metabolism in mESCs, respectively. Our findings indicate that the inhibition of ferroptosis can confer protective effects against decidual damage during LPS-induced early pregnancy loss in mice.

Abstract 4112620: Cardiomyocyte-specific Increases in Forkhead Box M1 (FoxM1) Expression May Promote Cardiomyocyte Proliferation and Improve Recovery from Myocardial Injury in Mice and Pigs

Background: The cardiomyocytes (CMs) can not regenerate after myocardial infarction (MI) in adult mammals. FoxM1 is essential for cell proliferation. Targeted deletion of the Foxm1 in mice leads to serious cardiac proliferation defects and embryo death. The primary aim of this study was to demonstrate that the Specific Modified mRNA Translation System (SMRTs) can specifically overexpress FoxM1 in CMs and observe the benefits of overexpressing FoxM1 on myocardial repair in mice and pigs with myocardial injury. Methods: The FoxM1-CM SMRTs is composed of two modRNA constructs: one encoding L7Ae regulates the specific expression of FoxM1 on the other coding chain in CMs and inhibits its expression in non-cardiomyocytes through he CM-specific microRNAs miR-1 and miR-208 on L7Ae coding chain. Myocardial-specific expression of FoxM1-CM SMRTs and its proliferation-promoting effect were detected in hiPSC-CM (human-induced pluripotent stem cell-derived cardiomyocyte), mouse and pig models (days 3 after FoxM1-CM SMRTs treatment). In vivo experiments were conducted in both mouse and pigs with LAD (left anterior descending) ligation. The effects of FoxM1-CM SMRTs on cardiac function, MI size and hypertrophy in mice and pig models were detected after 4 weeks of FoxM1-CM SMRTs treatment. Results: FoxM1 was abundantly expressed in postmitotic CMs after transfection with the FoxM1-CM SMRTs, accompanied by activation of cell-cycle and proliferation markers (Ki67, PH3 and Aurora B kinase) and an increase in cell number. When the GFP-CM SMRTs was injected into mouse hearts with MI, GFP was only expressed in CMs, but not in non-CMs. Compared with the MI group, FoxM1-CM SMRTs significantly increased CM proliferation (days 3 after treatment administration in mice and pigs), improved left-ventricular ejection fractions (days 10 and 28 in both species) and hypertrophy, and reduced MI size (days 28 in both species). Conclusion: Intramyocardial injections of the FoxM1-CM SMRTs promoted CM proliferation, reduced MI size, and improved cardiac function in small and large mammals with acute myocardial infarction.

A newborn F-box gene blocks gene flow by selectively degrading phosphoglucomutase in species hybrids

The establishment of reproductive barriers such as postzygotic hybrid incompatibility (HI) remains the key to speciation. Gene duplication followed by differential functionalization has long been proposed as a major model underlying HI, but little supporting evidence exists. Here, we demonstrate that a newborn F-box gene, Cni-neib-1, of the nematode Caenorhabditis nigoni specifically inactivates an essential phosphoglucomutase encoded by Cbr-shls-1 in its sister species Caenorhabditis briggsae and their hybrids. Zygotic expression of Cni-neib-1 specifically depletes Cbr-SHLS-1, but not Cni-SHLS-1, in approximately 40 min starting from gastrulation, causing embryonic death. Cni-neib-1 is one of thirty-three paralogues emerging from a recent surge in F-box gene duplication events within C. nigoni, all of which are evolving under positive selection. Cni-neib-1 undergoes turnover even among C. nigoni populations. Differential expansion of F-box genes between the two species could reflect their distinctive innate immune responses. Collectively, we demonstrate how recent duplication of genes involved in protein degradation can cause incidental destruction of targets in hybrids that leads to HI, providing an invaluable insight into mechanisms of speciation.

Influence of hormonal treatments on progesterone levels to enhance embryo survival and kidding rates in goats.

This study investigated the efficiency of different estrous synchronization programs and hormonal treatments in improving reproductive outcomes in goats. Conducted on a commercial farm in southern Thailand, the study used multiparous Shami and Anglo-Nubian breed goats. In experiment 1, goats were randomly allocated to two estrous synchronization treatments: 11-day (CI11D) and 13-day (CI13D) intravaginal progesterone implants, followed by artificial insemination (AI) with frozen-thawed semen. Various hormonal treatments (human chorionic gonadotropin (hCG), GnRH analogue, progestogen) were administered on day 5 post-AI to elevate progesterone levels. Experiment 2 assessed embryo survival after transferring early- and late-stage embryos, using GnRH analogue to increase progesterone levels in the recipient goats. Results showed that GnRH analogue significantly increased pregnancy rates, kidding rates, and the number of kids born in the CI13D group. Progesterone levels were higher in treated groups, particularly with GnRH analogue, though estradiol levels varied between synchronization protocols. Late-stage embryo transfers significantly improved pregnancy rates and reduced embryonic loss compared to early-stage transfers. GnRH analogue supplementation reduced early embryonic mortality, enhancing embryo survival and overall reproductive performance. This study demonstrates the efficacy of tailored estrous synchronization and hormonal treatments in optimizing goat reproductive outcomes, with significant implications for improving fertility management in commercial goat farming. Although no significant differences were observed in progesterone levels, the administration of GnRH analogue reduced early embryonic mortality and improved reproductive outcomes, demonstrating its potential to enhance embryo survival and reproductive performance in goats.

Kefir peptides mitigate L-NAME-induced preeclampsia in rats through modulating hypertension and endothelial dysfunction

AimPreeclampsia is a complex and serious pregnancy disorder that leads to maternal and neonatal mortality worldwide. Kefir peptides (KPs), derived from various prebiotic fermentations in whole milk by kefir grains, were investigated for their potential therapeutic effects. In this study, we used the L-NAME in drinking water to induce a preeclampsia-like condition in spontaneous hypertension stroke-prone (SHRSP) pregnant rats. Main methodsThe rats were assigned to five groups: the normal group (WKY rats), the untreated group (SHRSP rat control pregnant), the L-NAME/Mock group (SHRSP rats fed with L-NAME water), the L-NAME/KPs-LD group (SHRSP rats fed with L-NAME water and low-dose KPs diets), and the L-NAME/KPs-HD group (SHRSP rats fed with L-NAME water and high-dose KPs diets) for a 20-day experiment. Chorioallantois membrane (CAM) assay was applied for ex vivo angiogenesis study of KPs treatment. Key findingsData showed that rats in the L-NAME group developed severe hypertension, proteinuria, placental damage, and embryo resorption. Pre-administration of KPs significantly reduced hypertension, proteinuria, improved generalized endothelial dysfunction, and decreased levels of anti-HIF-1α, sFLT1, anti-TNF-α, and IL-6 in the placenta of SHRSP rats. In ex vivo CAM study, L-NAME administration in chicken embryos resulted in lower vessel density and hemorrhage; however, angiogenesis was observed after KPs-HD treatment. SignificanceThe results indicate that kefir peptides improve renal lesions, prevent renal parenchyma damage, and balance endothelial and angiogenic dysfunction in both maternal and fetal sites in L-NAME-induced SHRSP pregnant rats.

Genomic regions associated with embryonic loss in primiparous Holstein cows

IntroductionReproductive efficiency in dairy cattle bred by artificial insemination (AI) or via embryo transfer (ET) is important as a means of facilitating the rate of genetic improvement by utilizing superior genetics from sires and donor dams. Fertility is especially challenging in primiparous cows as they have recently calved, are still growing, and are lactating. Fertility, measured by the conception rate from the first service (CCR1), is the number of cows that become pregnant as a result of the first AI or ET compared to all cows serviced, whereas times bred (TBRD) is the number of inseminations cows bred by AI needed to achieve a successful pregnancy.MethodsThis study aimed to identify the loci associated with and gene sets enriched for the CCR1 in primiparous cows that were bred by AI (n = 882) or were ET recipients (n = 353), and to identify the loci associated with the TBRD (n= 1,851) in primiparous cows. A genome-wide association analysis and gene set enrichment analysis were performed using single-nucleotide polymorphism (SNP) data for the CCR1 and TBRD in primiparous cows. In cows bred by AI, two loci containing five positional candidate genes were associated with the CCR1 (p < 1 × 10−5) and one gene set with 18 leading-edge genes was enriched (NES ≥3) for the CCR1.Results and discussionIn cows that were ET recipients, five loci were associated with the CCR1, but no gene sets were enriched for the CCR1. For the second phenotype, five loci with nine positional candidate genes were associated with the TBRD and two gene sets with eight leading-edge genes were enriched for the TBRD. Identifying the loci associated with or gene sets enriched for the CCR1 and TBRD provides an opportunity to better understand embryonic loss in AI-bred and ET-recipient cows and to use this information to select for higher reproductive efficiency.

Effects of intrauterine extracellular vesicle microRNAs on embryonic gene expression in low-fertility cows.

Embryo survival and pre-implantation development depend on uterine luminal fluid, which is believed to play a role in early embryonic death and infertility in cows. Extracellular vesicles (EVs) in the uterine luminal fluid contain microRNAs (miRNAs), crucial mediators of intercellular communication. miRNAs regulate conceptus-maternal interactions and participate in embryonic development by suppressing gene expression. Therefore, we hypothesized that miRNAs in the intrauterine EVs of low-fertility cows would hinder embryonic survival and development. EVs were collected from the bovine uterine luminal fluid of both normal- and low-fertility cows 7 days post-estrus. Small RNA-sequencing analysis of miRNAs isolated from these EVs identified eight miRNAs that were highly expressed in normal-fertility cows (normal-fertility miRNAs) and eight with elevated expression in low-fertility cows (low-fertility miRNAs). These two sets of miRNAs were transfected into hatched blastocysts via lipofection. RNA-seq following lipofection with low-fertility miRNAs identified 424 differentially expressed genes (DEGs) relative to the control; in contrast, following lipofection with normal-fertility miRNAs, seven DEGs were identified. Pathway analysis of the DEGs identified following lipofection with low-fertility miRNAs revealed substantial enrichment of mitogen-activated protein kinase (MAPK) signaling. Expression of activator protein 1 (AP1) and interferon-tau (IFNT) mRNA was significantly lower in the low-fertility miRNA transfection group than in the control. IFNT is essential for maternal pregnancy recognition. Therefore, miRNAs in intrauterine EVs from low-fertility cows at 7 days post-estrus may inhibit embryo development and suppress IFNT expression by altering MAPK signaling.

Uterine stromal but not epithelial PTGS2 is critical for murine pregnancy success.

Use of non-steroidal anti-inflammatory drugs that target prostaglandin synthase (PTGS) enzymes have been implicated in miscarriage. Further, PTGS2-derived prostaglandins are reduced in the endometrium of patients with a history of implantation failure. However, in the mouse model of pregnancy, peri-implantation PTGS2 function is controversial. Some studies suggest that Ptgs2 -/- mice display deficits in ovulation, fertilization, and implantation, while other studies suggest a role for PTGS2 only in ovulation but not implantation. Further, the uterine cell type responsible for PTGS2 function and role of PTGS2 in regulating implantation chamber formation is not known. To address this we generated tissue-specific deletion models of Ptgs2 . We observed that PTGS2 ablation from the epithelium alone in Ltf cre/+ ; Ptgs2 f/f mice and in both the epithelium and endothelium of the Pax2 cre/+ ; Ptgs2 f/f mice does not affect embryo implantation. Further, deletion of PTGS2 in the ovary, oviduct, and the uterus using Pgr cre/+ ; Ptgs2 f/f does not disrupt pre-implantation events but instead interferes with post-implantation chamber formation, vascular remodeling and decidualization. While all embryos initiate chamber formation, more than half of the embryos fail to transition from blastocyst to epiblast stage, resulting in embryo death and resorbing decidual sites at mid-gestation. Thus, our results suggest no role for uterine epithelial PTGS2 in early pregnancy but instead highlight a role for uterine stromal PTGS2 in modulating post-implantation embryo and implantation chamber growth. Overall, our study provides clarity on the compartment-specific role of PTGS2 and provides a valuable model for further investigating the role of stromal PTGS2 in post-implantation embryo development.

DDX41 dissolves G-quadruplexes to maintain erythroid genome integrity and prevent cGAS-mediated cell death.

Deleterious germline DDX41 variants constitute the most common inherited predisposition disorder linked to myeloid neoplasms (MNs). The role of DDX41 in hematopoiesis and how its germline and somatic mutations contribute to MNs remain unclear. Here we show that DDX41 is essential for erythropoiesis but dispensable for the development of other hematopoietic lineages. Using stage-specific Cre models for erythropoiesis, we reveal that Ddx41 knockout in early erythropoiesis is embryonically lethal, while knockout in late-stage terminal erythropoiesis allows mice to survive with normal blood counts. DDX41 deficiency induces a significant upregulation of G-quadruplexes (G4), noncanonical DNA structures that tend to accumulate in the early stages of erythroid precursors. We show that DDX41 co-localizes with G4 on the erythroid genome. DDX41 directly binds to and dissolves G4, which is significantly compromised in MN-associated DDX41 mutants. Accumulation of G4 by DDX41 deficiency induces erythroid genome instability, defects in ribosomal biogenesis, and upregulation of p53. However, p53 deficiency does not rescue the embryonic death of Ddx41 hematopoietic-specific knockout mice. In parallel, genome instability also activates the cGas-Sting pathway, which is detrimental to survival since cGas-deficient and hematopoietic-specific Ddx41 knockout mice are viable without detectable hematologic phenotypes, although these mice continue to show erythroid ribosomal defects and upregulation of p53. These findings are further supported by data from a DDX41 mutated MN patient and human iPSC-derived bone marrow organoids. Our study establishes DDX41 as a G4 dissolver, essential for erythroid genome stability and suppressing the cGAS-STING pathway.

Genetic characteristics and pathogenicity of variant porcine parvovirus 1 in northern China

Porcine parvovirus type 1 (PPV1) can lead to reproductive disorders in pregnant sows, including stillbirth, mummification, embryonic death, and infertility (SMEDI syndrome). In this study, we isolated and identified 10 PPV1 strains in northern China, with genomes around 5 kb long and minor deletions in the 127-nt repeat region. The sequence analysis results showed that compared with strain NADL-2 (Reference strain), eight amino acid substitutions on the NS1 protein and fourteen amino acid substitutions on the VP2 protein were found in the ten isolates. Because the JX strain exhibited reduced neutralizing activity induced by commercially available vaccines in vitro, it was selected for challenge experiments in sows at 35 days of gestation. Mutant strain JX not only caused viremia, but also mild edema and mild inflammation in the trachea, lungs, lymph nodes, reproductive organs, and some intestines of the pregnant sows. Strain JX also caused fetal congestion and organ infection after penetrating the placental barrier. In conclusion, this study focused on the variation and evolution of PPV1 in northern China, screened a strain with reduced neutralizing activity, and determined that it has a certain degree of pathogenicity.

Silencing of maternally expressed RNAs in Dlk1-Dio3 domain causes fatal vascular injury in the fetal liver

The mammalian imprinted Dlk1-Dio3 domain contains multiple lncRNAs, mRNAs, the largest miRNA cluster in the genome and four differentially methylated regions (DMRs), and deletion of maternally expressed RNA within this locus results in embryonic lethality, but the mechanism by which this occurs is not clear. Here, we optimized the model of maternally expressed RNAs transcription termination in the domain and found that the cause of embryonic death was apoptosis in the embryo, particularly in the liver. We generated a mouse model of maternally expressed RNAs silencing in the Dlk1-Dio3 domain by inserting a 3 × polyA termination sequence into the Gtl2 locus. By analyzing RNA-seq data of mouse embryos combined with histological analysis, we found that silencing of maternally expressed RNAs in the domain activated apoptosis, causing vascular rupture of the fetal liver, resulting in hemorrhage and injury. Mechanistically, termination of Gtl2 transcription results in the silencing of maternally expressed RNAs and activation of paternally expressed genes in the interval, and it is the gene itself rather than the IG-DMR and Gtl2-DMR that causes the aforementioned phenotypes. In conclusion, these findings illuminate a novel mechanism by which the silencing of maternally expressed RNAs within Dlk1-Dio3 domain leads to hepatic hemorrhage and embryonic death through the activation of apoptosis.

Nest Box Cameras Provide Insight into Causes of Nest Failure for American Kestrels

ABSTRACT Although nest failure is a common occurrence in birds, oftentimes the causes, or details, of the failure are unknown because nests cannot be monitored closely or continuously. This inability to monitor nests in ways that allow for a detailed understanding of nest failure can hamper our ability to conserve declining species, such as the American Kestrel (Falco sparverius). Here we describe previously unreported observations from continuous video monitoring in kestrel nest boxes and biweekly nest monitoring via an extendable fiber optic endoscopic camera. From continuous video monitoring we observed adult kestrels consume a kestrel egg with little to no development and a European Starling (Sturnus vulgaris) pierce and remove an abandoned kestrel egg from a nest box. From biweekly monitoring with a fiber optic camera, we inferred that nest abandonment by kestrels was associated with eggs not developing either from infertility or early-stage embryo death. Although it is unclear how common such occurrences may be across the broader range of kestrels, these observations may provide impetus to explore these causes of nest failure more closely.

Vascular Alterations in Uterine and Ovarian Hemodynamics and Hormonal Analysis throughout Pregnancy Loss in Cows under Heat Stress.

This current study examined the ovarian (OA) and middle uterine arteries (MUA) blood flow under heat stress conditions regarding hormonal status (progesterone (P4), estradiol (E2), and nitric oxide metabolites (NOMs) assays). Eighteen pluriparous cows were examined, with twelve only being subjected to the natural mating as the other six animals were not bred. Pregnancy diagnosis was confirmed at day 30 by embryonic heartbeat and CL graviditatis (n = 6; pregnant), but some animals (n = 6) showed early embryonic death (EED), with the presence of control cows (n = 6). In the pregnant group, luteal diameter (cm) increased after mating, while in the pregnancy loss group it increased (p < 0.05) until reaching day 38 (1.41 ± 0.03), then decreased again. Luteal vascularity was declined in cows with EED after day 36 (p < 0.05) and reached its lowest level at day 50. P4 levels elevated in cows with EED until day 36 (13.64 ± 0.11) then declined. Both ipsilateral OA and MUA Doppler indices were declined in both groups except in cows who suffered from EED; both were elevated from day 38 until day 50 after mating. Ipsilateral peak systolic point (PSV cm/sec) of OA and MUA was elevated in both groups (p < 0.05), but in cows with EED this parameter was declined. E2 and NOMs levels were declined in cows with EED from day 40 and day 38 after mating (p < 0.05), respectively. This study provided novel data on the relations among the luteal diameter, E2, P4, and NOM levels, and luteal hemodynamics that predicts the amount of blood supply, which acts as a sensitive parameter to detect the alterations in luteal function during the first 50 days after mating.

Use of corn germ meal and bile acids in laying quail diets: effect on production, reproduction, health and economics

In the present study, the effects of corn germ meal (CGM) and bile acids (BA) inclusion in Japanese quail diet on the productive and reproductive performance, egg quality, and serum biochemical parameters were evaluated. Six wk old, 480 Japanese quail birds were randomly divided into 6 groups (60 hens and 20 males / group) with 4 replicates / group. CGM was incorporated at 0, 10 and 20 % of diet for groups (G1, G2, and G3), while G4, G5 and G6 had the same levels of CGM with BA addition (500 g/ton feed). The egg production (EP), egg mass (EM) and feed intake (FI) were significantly reduced (P < 0.05) in response to CGM feeding which was clear with the 20 %. CGM at 10% inclusion enhanced the feed conversion ratio (FCR), while incorporation at 20% deteriorated (P < 0.05) it compared to the control group. Addition of BA to the CGM-containing diets reduced the FI, improved FCR, and ameliorated the negative effects on EP, EM and FCR in the CGM fed birds. Feeding on 10% CGM single or combined with BA increased fertility %, chick's weight after hatching and reduced embryonic death. Serum concentrations of triglyceride and low-density lipoprotein (LDL) were significantly increased (P < 0.05) with CGM inclusion. Dietary CGM inclusion without or with BA was associated with higher levels of serum total cholesterol and low-density lipoprotein when compared to their control groups. BA addition to the CGM containing diets significantly reduced the alanine transaminase (ALT) activity (P ˂ 0.05) compared to their corresponding groups fed BA free diets especially those received the 10% CGM. Birds fed on 10% CGM supplemented with BA showed the highest economic efficiency values. In conclusion, CGM inclusion at 10% with BA supplementation could be used as alternative ingredient in the Japanese quail layer diet without compromising their productive performance.

Potential Teratogenicity Effects of Metals on Avian Embryos

Agricultural areas can provide sources of food and hiding and nesting places for wild birds. Thus, the chemical load of potentially toxic elements (Cd, Cu, Pb) due to industrial and agricultural activities can affect not only the adult birds but also the embryos developing in the egg. The toxic effects of heavy metals applied alone were investigated on chicken embryos in the early and late stages of embryonic development using injection and immersion treatment methods. On day 3 of incubation, permanent preparations were made from the embryos to study the early development stage. There were no significant differences observed in embryo deaths and developmental abnormalities in this stage. On day 19 of incubation, the number of embryonic deaths, the body weight of the embryos, and the type of developmental abnormalities were examined. The embryonic mortality was statistically higher in the groups treated with cadmium and lead in the case of the injection treatment. A significant increase in developmental disorders was observed in the copper-treated group using the immersion application. The body weight significantly decreased in the cadmium- and lead-treated group using both treatment methods. However, a significant change in the body weight in the copper-treated group was only realized due to the injection method.

Ultrasound assessment of embryo cardiac function as a predictive criterion of adverse pregnancy outcome

Purpose to evaluate the value of the embryo/fetus heart rate (HR) in early pregnancy assessed by ultrasound for the formation of a group at high risk of adverse pregnancy outcomes.Materials and methods. A retrospective analysis of ultrasound examinations of 1073 pregnant women at 5+0–10+6 weeks was carried out. The embryo/fetus heart rate was compared with the gestational age calculated by the crown rump length (CRL) and the date of the last menstruation period (LMP). Retrospectively, all examined pregnant women were divided into two groups: group 1—with intrauterine embryo death before 14 weeks of pregnancy (n = 107); group 2—with prolongation of pregnancy until the second trimester (n = 966). When analyzing the data array using a decision tree, the embryo heart rate was assessed at various stages of pregnancy by LMP, CRL, and regardless of the exact period of pregnancy.Results. Analysis of heart rate values at different stages of pregnancy by LMP showed significant differences in heart rate between groups, the cases of later embryo loss characterized by lover heart rate values. There were no significant differences in heart rate between the groups at different stages of pregnancy by CRL (significant differences were obtained only at 8+0–9+6 weeks). Cut-off values of embryo heart rate for prediction of adverse pregnancy outcomes have been proposed for different stages of pregnancy, as well as a universal cut-off for the entire embryonic period.Conclusion. The proposed cut-off values of embryo heart rate for different stages of pregnancy, calculated by LMP, may be used for timely prediction of adverse pregnancy outcomes. When the exact gestational age is unknown, a universal heart rate cut-off value of &lt;116 bpm may be used. All proposed HR cut-off values were characterized by high specificity, but none of them by high sensitivity. A sensitivity of HR cut-off values can be increased by the use in combination with other ultrasound and clinical signs of adverse pregnancy outcome.

Fungal endometritis associated with embryonic loss in a maiden mare

SummaryFungal endometritis and placentitis have been reported as a rare but important cause of infertility in the mare. There are no reported clinical cases of fungal endometritis causing embryonic loss in the mare. This case report aims to highlight the potential of fungal endometritis as an aetiological agent in embryonic loss in the mare; an incidental diagnosis of a case of fungal endometritis and embryonic loss while undertaking routine pregnancy assessments in a Standardbred mare. After a positive pregnancy diagnosis after 13 days post‐ovulation, a mare was diagnosed with endometritis and pregnancy loss associated with the growth of an unusual fungus, likely of the Acremonium spp., 28 days post‐ovulation. While fungal embryonic loss is rare, it should be considered a potential reason for pregnancy wastage in the mare.

Tritrichomonas foetus testing in bulls.

To provide a video tutorial on how to perform preputial scraping for the testing of Tritrichomonas foetus in bulls. Postpubertal bulls. A preputial scraping device is inserted in the prepuce, and back-and-forth scraping movements are made to collect smegma and T foetus organisms. The sample is placed in an appropriate media and prepared for shipment to the diagnostic laboratory. Preputial sampling is an effective method for diagnosing T foetus in infected bulls. Bulls are the primary carriers of T foetus, a protozoan parasite responsible for bovine trichomoniasis. By sampling and testing bulls, veterinarians can identify infected animals and implement control measures to prevent the spread of the disease within herds. Trichomoniasis can lead to significant reproductive problems in cattle, including infertility, embryonic death, and abortions. Sampling bulls allows for the detection of infection, enabling prompt intervention to protect the reproductive health of the entire herd. Trichomoniasis outbreaks can result in substantial economic losses for cattle producers due to reduced conception rates, increased calving intervals, and decreased calf crops. Sampling bulls helps to mitigate these losses by identifying and removing infected animals from the breeding pool, thereby minimizing the spread of the disease and its associated reproductive inefficiencies. In many regions, T foetus testing in bulls is a regulatory requirement for cattle movement and trade. Sampling bulls and obtaining negative test results are often necessary for obtaining health certificates and complying with interstate or international movement regulations.

Repeat Breeder Syndrome Therapies in Dairy Cows: A Review.

Repeat breeder (RB) cows are clinically healthy animals with regular oestrous cycles that do not become pregnant after three or more services. This syndrome has an incidence ranging between 10.1% and 24%. Repeat breeder syndrome (RBS) in dairy cows leads to economic losses to dairy farmers by increasing the calving interval and consequently reducing milk and calf production. RBS has a complex oetiopathogenesis as many factors are involved in its onset. The causes can be grouped into two categories: causes leading to fertilisation failure and factors leading to early embryonic death. Accurate identification of the cause and early diagnosis of RBS is essential to minimise the problems that this issue brings to the farm, but is not always possible. Hypothesising the underlying aetiology of the syndrome is also crucial for targeted therapy, whether pharmacological or managerial. The aim of this review is to report the different therapies, proposed in the literature, for the treatment of RBS in cattle, based on the knowledge of possible aetiological causes.

Sodium channels Nav1.7, Nav1.8 and pain; two distinct mechanisms for Nav1.7 null analgesia

Genetic deletion and pharmacological inhibition are distinct approaches to unravelling pain mechanisms, identifying targets and developing new analgesics. Both approaches have been applied to the voltage-gated sodium channels Nav1.7 and Nav1.8. Genetic deletion of Nav1.8 in mice leads to a loss of pain and antagonists are effective analgesics. The situation with Nav1.7 is more complex. Complete embryonic loss of Nav1.7 in humans or in mouse sensory neurons leads to anosmia as well as profound analgesia as a result of diminished neurotransmitter release. This is mediated by enhanced endogenous opioid signaling in humans and mice. In contrast, anosmia is opioid-independent. Sensory neuron excitability and autonomic function appear to be normal.Adult deletion of Nav1.7 in sensory neurons also leads to analgesia, but through diminished sensory and autonomic neuron excitability. There is no opioid component of analgesia or anosmia as shown by a lack of effect of naloxone. Pharmacological inhibition of Nav1.7 in mice and humans leads both to analgesia and dramatic side-effects on the autonomic nervous system with no therapeutic window. These data demonstrate that specific Nav1.7 channel blockers will fail as analgesic drugs. The viability of embryonic null mutants suggests that there are compensatory changes to replace the lost Nav1.7 channel. Here we show that sensory neuron sodium channels Nav1.1, Nav1.2 and β4 subunits detected by Mass Spectrometry are upregulated in Nav1.7 embryonic null neurons and, together with other proteome changes, potentially compensate for the loss of Nav1.7. Interestingly, many of the upregulated proteins are known to interact with Nav1.7.