Search Results (221)

Nectar robbing typically reduces nectar availability to pollinators, damages flower structure, and/or induces secondary robbing. Consequently, it may reduce pollen deposition and seed set, increase pollination efficiency and outcrossing, and/or not affect reproduction in some species. However, spatiotemporal variations in nectar robbing and their effects on plant reproduction have received little attention. In this study, we assessed the effects of nectar robbing on floral visits, seed set, nectar volume and concentration, and flower longevity in two populations of Salvia castanea Diels (Lamiaceae) in the Himalayan region of Southwestern China in 2014–2020. We also examined whether one or a few visits by pollinators can result in the stigma receiving sufficient pollen to fertilize all ovules of S. castanea. We found that significant differences in the nectar robbing rate did not affect seed set in any of the years for either population of S. castanea. In the robbed and unrobbed flowers, nectar was consistently replenished every night at higher concentrations. Bagging, nectar robbing, and sufficient pollination did not affect flower longevity. Salvia castanea required only 5–10 pollen grains to achieve the maximum seed set. However, pollinators depositing more than 10 pollen grains after a single visit ensured a high seed set of >80%. Our results suggest that nectar availability, floral longevity maintenance, and sufficient pollen deposition mitigate the effects of nectar robbing on the reproductive success of S. castanea. These results are expected to further our understanding of plant–animal interactions and the ecological consequences of nectar robbing. Full article

The asynchrony of cytoplasmic and nuclear maturation in cumulus–oocyte complexes (COCs) due to prematurely declining concentrations of cyclic adenosine monophosphate (cAMP) has been shown to result in reduced oocyte developmental competence. The objective of this study was to evaluate the effect of pre-IVM treatment with cAMP modulators for different durations on the developmental potential of equine oocytes used for cloned embryo production. Collected COCs were transferred to cryovials filled with transport medium at 20–22 °C. Within the cryovials, the COCs were either untreated (Control) for 18 h or treated with 50 µM forskolin and 100 µM 3-isobutyl-1-methylxanthine for the first 4 h (Pre-IVM 4 h) or the entire 18 h (Pre-IVM 18 h). Oocytes were then transferred to maturation medium and incubated for a further 22–24 h at 38.5 °C in 5% CO₂ in air. Somatic cell nuclear transfer embryos were then produced using the meiotically mature oocytes and donor cells from six different fibroblast cell lines. The rates of maturation and embryo development did not differ significantly between the groups, though blastocyst formation tended to be inferior in the Pre-IVM 4 h group compared with the Control group (p = 0.06). Of 67 blastocysts produced, 23 were transferred to recipient mares on Day 4 or 5 post-ovulation. Regarding the pregnancy outcomes, no significant differences were found between the groups, and four viable foals were born, each derived from a different donor cell line. The findings expand on those from previous evaluations of this biphasic IVM system, and indicate that the cAMP-modulating treatments exert limited effects under the pre-IVM conditions used here. Full article

The transforming growth factor-beta (TGF-β) superfamily plays a crucial role in regulating female reproductive traits, particularly litter size, in small ruminants, such as sheep and goats. This review comprehensively examines the molecular mechanisms through which TGF-β superfamily members—including bone morphogenetic proteins (BMPs), growth differentiation factor 9 (GDF9), inhibin (INHA and INHB), and associated signaling genes—influence ovarian follicular development, ovulation rate, and ultimately, litter size. We synthesize recent findings on polymorphisms in key genes, such as BMPR1B, BMP15, GDF9, inhibins and SMADs family genes, across diverse sheep and goat breeds worldwide. The manuscript highlights how specific mutations in these genes create an intricate signaling network that modulates granulosa cell proliferation, follicular sensitivity to FSH, and the prevention of dominant follicle selection. These molecular interactions result in increased ovulation rates and larger litter sizes in prolific breeds. The gene dosage effects observed in heterozygous versus homozygous mutation carriers further illuminate the complex nature of these reproductive regulations. This improved the understanding of the genetic basis for prolificacy provides valuable insights for marker-assisted selection strategies aimed at enhancing reproductive efficiency in small ruminant breeding programs, with significant implications for improving livestock productivity and economic outcomes. Full article

Background: Infertility affects 8–12% of couples globally, with causes including hormonal and structural abnormalities. Letrozole, an aromatase inhibitor, is commonly used for ovulation induction, but its role in various assisted reproductive technologies (ARTs) and across different subgroups of infertile women remains unclear. Objective: This scoping review aimed to map the existing evidence on the use of letrozole in assisted reproductive cycles, focusing on reproductive outcomes and its application across different patient populations. Methods: A scoping review was conducted following the PRISMA-ScR guidelines. Twelve studies—including randomized controlled trials and retrospective cohorts—were identified through a structured search strategy. Studies comparing letrozole alone or in combination with gonadotropins/clomiphene to other stimulation protocols were included. Data were charted across multiple outcomes including oocyte yield, implantation, pregnancy, miscarriage, and live birth rates. Results: Evidence suggests that letrozole-based protocols may enhance oocyte yield and improve reproductive outcomes in certain settings. The highest implantation rate (57%) was observed in natural cycles, while the letrozole-only group showed the highest clinical pregnancy (50.57%) and live birth rates (45.58%). Combination protocols achieved the highest ongoing pregnancy rate (58.3%), with the lowest miscarriage rate (14.86%) in the letrozole-only group. Conclusions: Letrozole appears to be a versatile agent in ART, especially for patients requiring reduced gonadotropin doses or estradiol modulation. This scoping review highlights the need for further research to clarify its optimal use across different infertility subgroups and ART modalities. Full article

Many researchers focus on improving reproductive health in sows and ensuring successful breeding by accurately identifying the optimal time of ovulation through estrus detection. One promising non-contact technique involves using computer vision to analyze temperature variations in thermal images of the sow’s vulva. However, variations in camera distance during dataset collection can significantly affect the accuracy of this method, as different distances alter the resolution of the region of interest, causing pixel intensity values to represent varying areas and temperatures. This inconsistency hinders the detection of the subtle temperature differences required to distinguish between estrus and non-estrus states. Moreover, failure to maintain a consistent camera distance, along with external factors such as atmospheric conditions and improper calibration, can distort temperature readings, further compromising data accuracy and reliability. Furthermore, without addressing distance variations, the model’s generalizability diminishes, increasing the likelihood of false positives and negatives and ultimately reducing the effectiveness of estrus detection. In our previously proposed methodology for estrus detection in sows, we utilized YOLOv8 for segmentation and keypoint detection, while monocular depth estimation was used for camera calibration. This calibration helps establish a functional relationship between the measurements in the image (such as distances between labia, the clitoris-to-perineum distance, and vulva perimeter) and the depth distance to the camera, enabling accurate adjustments and calibration for our analysis. Estrus classification is performed by comparing new data points with reference datasets using a three-nearest-neighbor voting system. In this paper, we aim to enhance our previous method by incorporating the mean pixel intensity of the region of interest as an additional factor. We propose a detailed four-step methodology coupled with two stages of evaluation. First, we carefully annotate masks around the vulva to calculate its perimeter precisely. Leveraging the advantages of deep learning, we train a model on these annotated images, enabling segmentation using the cutting-edge YOLOv9 algorithm. This segmentation enables the detection of the sow’s vulva, allowing for analysis of its shape and facilitating the calculation of the mean pixel intensity in the region. Crucially, we use monocular depth estimation from the previous method, establishing a functional link between pixel intensity and the distance to the camera, ensuring accuracy in our analysis. We then introduce a classification approach that differentiates between estrus and non-estrus regions based on the mean pixel intensity of the vulva. This classification method involves calculating Euclidean distances between new data points and reference points from two datasets: one for “estrus” and the other for “non-estrus”. The classification process identifies the five closest neighbors from the datasets and applies a majority voting system to determine the label. A new point is classified as “estrus” if the majority of its nearest neighbors are labeled as estrus; otherwise, it is classified as “non-estrus”. This automated approach offers a robust solution for accurate estrus detection. To validate our method, we propose two evaluation stages: first, a quantitative analysis comparing the performance of our new YOLOv9 segmentation model with the older U-Net and YOLOv8 models. Secondly, we assess the classification process by defining a confusion matrix and comparing the results of our previous method, which used the three nearest points, with those of our new model that utilizes five nearest points. This comparison allows us to evaluate the improvements in accuracy and performance achieved with the updated model. The automation of this vital process holds the potential to revolutionize reproductive health management in agriculture, boosting breeding success rates. Through thorough evaluation and experimentation, our research highlights the transformative power of computer vision, pushing forward more advanced practices in the field. Full article

This study investigated how environmental temperature affects estrus behavior and pregnancy rates in lactating dairy cows during induced estrus. We hypothesized that higher temperatures reduce estrus expression and pregnancy rates and influence hormone levels. Fifty-eight healthy, multiparous, ovulation-synchronized cows were studied under heat stress (summer) and non-stress (winter) conditions. Cows were assigned to G7G or OvSynch (OVS) hormone protocols. Blood samples collected on insemination day measured estradiol, LH, prolactin, insulin, and IGF-1 concentrations. Estrus signs and behaviors were also recorded. We found that during summer, daily maximum temperature–humidity Index (THI) values mostly exceeded 68, confirming the presence of heat stress. Estrus behaviors—especially standing and mounting—were significantly reduced under heat stress, occurring five to seven times more frequently in winter than in summer. Estrus detection rate was 86% in winter and 53% in summer. Pregnancy rates also declined sharply in summer (10%) compared to winter (39%), with all summer pregnancies in the G7G group. Hormonal analysis showed that estradiol levels remained consistent in the G7G group, while in the OVS group, it was significantly higher in winter than in summer. No significant seasonal differences were observed in the other hormones. Our findings indicate that heat stress impairs estrus expression and pregnancy rates in dairy cows. However, we conclude that the choice of hormone synchronization protocol (G7G) and the use of an automated estrus detection system may help to improve reproductive performance. Full article

The Chinese tongue sole (Cynoglossus semilaevis) is a commercially important mariculture species; however, its fertilization and hatching rates under artificial conditions remain relatively low. Zona pellucida proteins (ZPs), which mediate sperm–egg binding, were previously identified as differentially expressed genes between newly differentiated ovaries and testes in C. semilaevis. In this study, we identified 25 ZPs of C. semilaevis through genomic analysis and classified them into five subfamilies. All genes possessed a conserved ZP domain, characteristic of the gene family from mammals to teleosts. Among them, nine genes were highly expressed in ovary cells, with the expression levels increasing during ovarian development, while another three genes were predominantly expressed in liver cells. Protein–protein interaction analysis predicted that 12 ZPs interacted with key reproductive regulators such as Gdf9, Arid4a, Arid4b, and Rbl, which were involved in steroidogenesis, sperm–egg recognition, and folliculogenesis. Functional analyses using RNA interference revealed that Cszpc7-1 knockdown in ovarian cells led to the downregulation of cyp19a, esr2, bmp15, and adamts-1, while the expression of rbl, gnas, adgrl1, and adgrl2 was upregulated. In contrast, Cszpax1 knockdown resulted in decreased expression of cyp19a, foxl2, arid4a, and zeb1, along with upregulation of arid4b, ogg1, and gdf9. These results suggested that ZP genes might contribute to ovarian homeostasis by regulating steroid hormone synthesis, follicular development, and ovulation. This study contributed to a deeper understanding of the reproductive mechanisms of C. semilaevis and provided evolutionary insights into the functional divergence of the ZP gene family across teleosts. Full article

Nile tilapia (Oreochromis niloticus) is the most widely farmed tilapia species globally, making it one of the most important aquaculture species. To meet increasing demand, hatcheries occasionally use artificial breeding techniques such as hormonal induction to synchronize breeding. Despite the common use of human chorionic gonadotropin (hCG) in fish breeding, no detailed protocol has been established specifically for Nile tilapia. The objective of this study is to establish an effective hCG-induced artificial breeding protocol for gene editing and aquaculture production, optimizing fertilization, hatching, and survival rates. We employed a single intramuscular injection of 2 IU/g hCG to induce ovulation. The protocol achieved an average fertilization rate of 88.3% and a larval survival rate of 90.5%, demonstrating its potential for obtaining high-quality embryos for functional studies and enhancing reproductive performance on a commercial scale. Full article

Monitoring women’s health during the menstrual cycle is crucial. Traditional methods for estimating ovulation dates involve measuring body temperature and analyzing blood, urine, cervical mucus, or saliva. While effective, these methods come with various advantages and limitations. Therefore, we introduce a novel approach to more easily and accurately detect both the menstrual period and the ovulation date. After gathering essential physiological data from test subjects, the ovulation date is predicted. Heart rate waveform signals are used to identify physiological parameters linked to ovulation, enhancing prediction accuracy without relying on consumable items such as test strips or patches. By integrating non-invasive image signal processing technology and heart rate variability analysis algorithms, the timing of ovulation within the menstrual cycle is accurately predicted. Full article

Polycystic ovary syndrome (PCOS) is the expression of a complex alteration of the reproductive system. It is characterised by the increase in androgens, causing symptoms such as hirsutism, as well as infertility in many. This paper reviews whether Clomiphene Citrate, Letrozole and Inositol function better as monotherapy or combined therapy for anovulatory infertile PCOS patients. Ovulation and pregnancy rate were used as primary outcomes. PubMed and Scopus were the search engines of choice. Papers were excluded if patients were undertaking other fertility interventions, overlapping populations and non-RCT papers. It was found that co-prescribing Letrozole or Clomiphene Citrate alongside Metformin should be considered, Inositol should be examined as an alternative insulin sensitiser to Metformin and studies should be undertaken to identify the ideal dose and duration of Inositol therapy. Further large, well-designed, multi-centre studies should be conducted to solidify the claims of this review. Full article

Treating endometritis is one of the major challenges faced by veterinarians. The effect of post-insemination intrauterine infusion Wharton’s jelly mesenchymal stromal/stem cell-derived conditioned medium (WJ-MSC-CM) on the uterine response and pregnancy outcomes in problem mares was evaluated in this study. The cycles of 12 problem mares were treated seven/eight hours after insemination with intrauterine infusion of 20 mL of WJ-MSC-CM (TRT) or non-conditioned Ringer’s lactate solution (CTR). Before (PRE) and 12 h after (POST) treatment, an ultrasonographic examination and a low-volume flush (LVF) for efflux clarity evaluation and bacteriological and cytological analysis were made. Pregnancy diagnosis was performed at 14 days and confirmed at 60 days after ovulation. A decrease (p < 0.05) in polymorphonuclear neutrophils infiltration and a trend toward significance in LVF efflux clarity (p < 0.1) were observed in TRT cycles. The TRT (50%) had a higher pregnancy rate (p < 0.05) than CTR group (0%) at first cycle. Only a trend toward significance was observed comparing pregnancy frequencies between the two groups (CTR 12.5% vs. TRT 54.5%), the pregnancy rate of TRT cycles was comparable to that of normal mares (p > 0.05) and higher (p < 0.05) than that reported for problem mares in the literature. Post-insemination uterine infusion of WJ-MSC-CM in mares restores pregnancy rates to normal levels, by its anti-inflammatory effect. Full article

Haploid breeding technology has advantages in terms of saving time and reducing labor intensity and costs. However, the low induction rate limits the application of this technology. Previous researchers found that heat shock can increase the rate of Embryo-like structures (ELSs) induction. However, molecular mechanisms underlying heat-shocked haploid induction remain poorly understood. In the current study, unfertilized ovules of watermelon were subjected to heat shock for 0–5 days and conducted transcriptomics sequencing and DIA-based proteomics sequencing. Results indicated that, in contrast to the non-heat-shock condition, the expression level of protein phosphatase 2C (PP2C), a negative regulator in abscisic acid (ABA) signal transduction pathway, was repressed, and the expression level of Sucrose-non-fermenting 1-related protein kinases (SnRK2) was activated. The activated SnRK2s are enabled to promote the accumulation of storage substances in ovules. Through analysis, the expression of many genes involved in the biosynthesis of unsaturated fatty acids and amino acids has indeed been upregulated. In conclusion, our findings demonstrate that heat shock promotes the accumulation of storage substances in unfertilized ovules by activating the signal transduction process of ABA, which correspondingly increases ELSs induction rate. Full article

In a previous Arabidopsis investigation, three ovule-specific cell-wall peroxidases decreased seed abortion rates. These peroxidases were expressed in soybean plants. Because cell wall peroxidases alter extensibility, possible effects on seed size and plant yield were evaluated. Since the effects of these peroxidases in Arabidopsis were dependent on environmental stress, soybean plants were grown in controlled environment greenhouse rooms under four temperature treatments; the daily temperature averages were 26, 30, 34, and 38 °C. In this experiment in vivo oxygen levels during seed growth were 25-fold below ambient, which could affect peroxidase activities. Consequently, soybeans were grown at atmospheric (21%) and elevated (32%) O₂ to evaluate peroxidase activities at higher O₂. Chambers were maintained at 700 ppm CO₂ in an attempt to minimize photorespiration in elevated O_2. Individual seed weight decreased with increasing temperature to zero at 38 °C. In elevated O₂ rooms, the oxygen concentration in developing seeds increased, but, due to leaf photorespiration, plant biomass and seed yield decreased. Seed size and shelling percentage declined equally with temperature at both O₂ concentrations. Expression of all three cell-wall peroxidases reduced seed abortion; however, that did not increase yields at ambient or elevated O₂. While O₂ concentration is less than 1% in developing seeds, increased O₂ levels in seeds were not beneficial for soybean reproduction. Full article

It is not yet understood why cows that exhibit estrus and ovulate are more likely to become pregnant than those that ovulate but do not exhibit estrus during a fixed-time artificial insemination (FTAI) protocol. The objective of this work was to determine whether the follicular fluid from cows that exhibit estrus contributes to the increased likelihood of pregnancy. Lactating crossbred cows were subjected to an FTAI estrous synchronization protocol. Estrous behavior was observed and recorded prior to transvaginal follicle aspiration from cows that did (estrus, n = 7) or did not exhibit estrus (non-estrus, n = 6). Follicular fluid (25%) was then added to in vitro maturation media for the maturation of oocytes (n = 1489) from slaughterhouse ovaries. Cleavage rates were not affected by the estrous status of the cows from which the follicular fluid was collected. Blastocyst rates, however, were greater following maturation in the presence of follicular fluid from estrus cows compared to non-estrus cows (p ≤ 0.01). This difference in blastocyst rates was not related to blastocyst cell numbers (inner cell mass, trophoblast, and total), as they did not differ between estrus and non-estrus animals. This study demonstrates that the follicular fluid, and thus, the follicular environment just prior to ovulation does indeed contribute to improved pregnancy rates following FTAI. Full article

Background/Objectives: Vitamin D deficiency is common in women with polycystic ovary syndrome (PCOS) and may be associated with metabolic and endocrine disorders as well as ovulatory dysfunction. Vitamin D supplementation may improve ovarian dysfunction and follicular development by effecting gene expression. The aim of the present study was to investigate the effects of vitamin D supplementation in women with PCOS through a prospective, randomized, two-phase, parallel design, placebo-controlled trial. Methods: We assessed the impact on ovarian morphology, cycle length, and ovulatory dysfunction. Transvaginal ultrasonography (TVUS) examinations and clinical laboratory assessments were conducted at the baseline, and again after 12 and 24 weeks. The participants received vitamin D (30,000 IU/week) or a placebo (without concurrent metformin use) for 12 weeks, supplemented with calcium, followed by an additional 12 weeks of vitamin D treatment. Results: The treatment resulted in improvements in ovarian morphology and regularity of menstrual cycles in more than half of the patients. Additionally, vitamin D3 was associated with a significant increase in the ovulation rate. A statistically significant reduction in mean testosterone levels was observed in the subgroup of patients with an LH/FSH ratio greater than 2. Conclusions: Our results suggest that vitamin D3 treatment could function as either a standalone or an adjunctive therapy in the management of PCOS. Full article