Search Results (564)

(1) Background: Polyploid fish are highly important in increasing fish production, improving fish quality, and breeding new varieties. The loach (Misgurnus anguillicaudatus), as a naturally polyploid fish, serves as an ideal biological model for investigating the mechanisms of chromosome doubling; (2) Methods: In this study, tetraploidization in diploid loach was induced by heat shock treatment, and, for the first time, the role of the key cell cycle gene cdk1 (cyclin-dependent kinase 1) in chromosome doubling was investigated; (3) Results: The experimental results show that when eggs are fertilized for 20 min and then subjected to a 4 min heat shock treatment at 39–40 °C, this represents the optimal induction condition, resulting in a tetraploid rate of 44%. Meanwhile, the results of the cdk1 knockout model (2n cdk1^−/−) constructed using CRISPR/Cas9 showed that the absence of cdk1 significantly increased the chromosome doubling efficiency of the loach. The qPCR analysis revealed that knockout of cdk1 significantly upregulated cyclin genes (ccnb3,ccnc, and ccne1), while inhibiting expression of the separase gene espl1 (p < 0.05); (4) Conclusions: During chromosome doubling in diploid loaches induced by heat shock, knocking out the cdk1 gene can increase the tetraploid induction rate. This effect may occur through downregulation of the espl1 gene. This study offers novel insights into optimizing the induced breeding technology of polyploid fish and deciphering its molecular mechanism, while highlighting the potential application of integrating gene editing with physical induction. Full article

Drosophila suzukii is an invasive pest of many fruit crops worldwide. Employing the Sterile Insect Technique (SIT) could mitigate D. suzukii population growth and crop damage. This study evaluated the efficacy of SIT on commercial fruit, by (1) validating the quality of irradiated sterile males (male mating competitiveness, courtship, and flight performance) in the laboratory, and (2) assessing population suppression and fruit damage reduction in commercial raspberry fields. Treatment with SIT was compared to the grower’s standard chemical insecticide program throughout the season. The principal metrics of efficacy were trap counts of wild adult female D. suzukii in crops and larvae per fruit during harvesting. These metrics together with monitoring of border areas allowed targeting of high-pressure areas with higher releases of sterile males, to maximise efficacy for a given release number. The sterile male D. suzukii were as competitive as their fertile non-irradiated counterparts in laboratory mating competitiveness and flight performance studies while fertility egg-to-pupae recovery was reduced by 99%. In commercial raspberry crops, season-long releases of sterile males significantly suppressed the wild D. suzukii population, compared to the grower standard control strategy; with up to 89% reduction in wild female D. suzukii and 80% decrease in numbers of larvae per harvested fruit. Additionally, relative fruit waste (i.e., percentage of harvested fruits rejected for sale) at harvest was reduced for early, mid and late harvest crops, by up to 58% compared to the grower standard control. SIT has the potential to provide an effective and sustainable strategy for managing D. suzukii in raspberries, increasing marketable yield by reducing adult populations, fruit damage and waste fruit. SIT could therefore serve as a valuable tool for integrated pest management practices in berry production systems. Full article

Trichogramma wasps are highly effective biological control agents, offering an environmentally sustainable solution for pest management through their parasitism of insect eggs. This study evaluates the parasitism performance of six Trichogramma species—T. dendrolimi, T. chilonis, T. leucaniae, T. ostriniae, T. japonicum, and T. pretiosum—on five treatments of Eri silkworm (ES) eggs, a potential alternative to the large eggs of Antheraea pernyi for mass rearing. The ES egg treatments included the following: manually extracted, unfertilized, and washed eggs (MUW); naturally laid, unfertilized, and washed eggs (NUW); naturally laid, unfertilized, and unwashed eggs (NUUW); naturally laid, fertilized, and washed eggs (NFW); and naturally laid, fertilized, and unwashed eggs (NFUW). The results demonstrate that all Trichogramma species, except T. japonicum, successfully parasitized ES eggs across all treatments. Notably, washed eggs consistently supported higher parasitism and emergence rates compared to unwashed eggs, while unfertilized eggs outperformed fertilized eggs in these metrics. Among the treatments, unfertilized and washed eggs (MUW and NUW) exhibited the shortest pre-emergence time and the highest number of emerged adults, with no significant differences in female progeny ratios across most species. A striking exception was T. dendrolimi, which showed a significantly higher female offspring ratio in the MUW treatment. These findings highlight that MUW eggs of ES are a highly suitable alternative host for the mass production of Trichogramma wasps. This study provides critical insights for optimizing host egg treatments to enhance the efficiency of Trichogramma-based biological control programs. Full article

This study investigated the effects of dietary Gonadotropin-releasing hormone (GnRH) and domperidone on the reproductive performance of Devario devario during a 40-day trial. Five treatment groups received varying doses of GnRH (100, 50, 25, 12.5 µg/kg body weight) in combination with domperidone (50, 25, 12.5, 6.25 mg/kg body weight), embossed in a gel-based diet alongside a control group without the exogenous hormones. Reproductive performance was examined by measuring the gonadosomatic index, fecundity, reproductive hormone levels, and histological features of the gonads, blood parameters, and antioxidant enzyme activity. The T1 group (100 µg GnRH + 50 mg domperidone) exhibited the highest GSI in both sexes. The histological analysis of testes from T1, T2 (50 µg GnRH + 25 mg domperidone), and T3 (25 µg GnRH + 12.5 mg domperidone) groups revealed an increased presence of late-stage spermatids and spermatozoa. In females, the T2 group produced the highest proportion of advanced-stage oocytes and demonstrated the greatest absolute fecundity (1300 ± 23 eggs). However, the control group showed the highest fertilization and hatching rates. Testosterone levels were significantly elevated in the T3 group, while vitellogenin levels increased in the T1 and T2 groups. Antioxidant enzyme activity varied, with the T1 group displaying higher superoxide dismutase activity in gills and liver, and the T2 group showing increased SOD activity in muscle and brain. Improvements in haematological parameters were observed across all treatments. These results suggest that an optimal dose of 50 µg GnRH + 25 mg domperidone can enhance reproductive performance in D. devario. Full article

As a commercially valuable aquaculture species, rainbow trout (Oncorhynchus mykiss) urgently require solutions to growth inhibition associated with reproductive development. To elucidate the function of the cell cycle regulator Cyclin E genes (CCNE1 and CCNE2) in this process, we cloned the genes and analyzed their relative expression across various tissues and gonadal developmental stages. Using RNA interference (RNAi) and overexpression in RTG2 cells, we examined the effects of CCNE on cell viability, proliferation, and meiotic gene expression. Results showed that the open reading frame lengths of CCNE1 and CCNE2 were 1230 bp and 1188 bp, encoding 408 and 395 amino acids, respectively. Both proteins contain two conserved cyclin boxes, exhibit high structural similarity, and are phylogenetically most closely related to Oncorhynchus tshawytscha and Oncorhynchus kisutch. Expression and localization analyses revealed that CCNE1 was highly expressed in the ovary, while CCNE2 was highly expressed in the testis. Both proteins were expressed during fertilized egg development and key gonadal stages (at 13, 21, and 35 months post-fertilization). CCNE expression positively correlated with RTG2 cell viability and proliferation, with immunofluorescence confirming that CCNE is localized in the nucleus. Knockdown or overexpression of CCNE induced the differential expression of reproductive-related genes and key meiotic regulators. These findings suggest that CCNE1 and CCNE2 balance meiosis and gamete development through specific regulatory mechanisms, and their dysregulation may be a key factor underlying meiosis inhibition and reproductive development abnormalities. Full article

This study investigated the effects of feeding striped beakfish (Oplegnathus fasciatus) newly hatched larvae on the survival and growth of kawakawa (Euthynnus affinis) larvae and juveniles, as well as their relative growth patterns. Fertilized eggs of kawakawa were reared in 1 m³ experimental tanks until 13 days post-hatch (dph). From 3 to 8 dph, larvae were fed enriched rotifers, and from 9 to 12 dph, they were assigned to two experimental groups: one receiving only a formulated diet and the other receiving a combination of the formulated diet and 10,000 striped beakfish newly hatched larvae every day in each tank. The group fed newly hatched larvae exhibited approximately 36% greater growth than the group fed only the formulated diet. However, survival at 13 dph was approximately 34% lower, suggesting that further investigation is needed to determine the optimal feeding quantity of newly hatched larvae. The relative growth patterns of larvae and juveniles reared in a commercial 30 m³ tank showed morphological traits characteristic of scombrid fish, such as a longer preanal length and upper jaw length. Growth patterns varied at three key body lengths (notochord length or standard length; 3, 8–10, and 30 mm), as well as at their corresponding standard lengths. In kawakawa, the upper jaw exhibited early accelerated growth compared to other scombrid species. This characteristic is believed to facilitate the early onset of piscivory under captive conditions. Full article

The efficacy of in vitro fertilization (IVF) is significantly hindered by early embryonic developmental failure and oocyte maturation arrest. Recent findings in reproductive genetics have identified several oocyte-specific genes—TUBB8, KIF11, and CKAP5—as essential regulators of meiotic spindle formation and cytoskeletal dynamics. Mutations in these genes can lead to significant meiotic defects, fertilization failure, and embryo arrest. The links between genotype and phenotype, along with the underlying biological mechanisms, remain inadequately characterized despite the increasing number of identified variations. This systematic review was conducted in accordance with PRISMA 2020 guidelines. Relevant papers were retrieved from the PubMed and Embase databases using combinations of the keywords “TUBB8,” “KIF11,” “CKAP5,” “oocyte maturation arrest,” “embryonic arrest,” and “IVF failure.” Studies were included if they contained clinical, genomic, and functional data on TUBB8, KIF11, or CKAP5 mutations in women undergoing IVF. Molecular data, including gene variant classifications, inheritance models, in vitro tests (such as microtubule network analysis in HeLa cells), and assisted reproductive technology (ART) outcomes, were obtained. Eighteen trials including 35 women with primary infertility were included. Over fifty different variants were identified, the majority of which can be attributed to TUBB8 mutations. TUBB8 disrupted α/β-tubulin heterodimer assembly due to homozygous missense mutations, hence hindering meiotic spindle formation and leading to early embryo fragmentation or the creation of many pronuclei and cleavage failure. KIF11 mutations resulted in spindle disorganization and chromosomal misalignment via disrupting tubulin acetylation and microtubule transport. Mutations in CKAP5 impaired bipolar spindle assembly and microtubule stabilization. In vitro validation studies showed cytoskeletal disturbances, protein instability, and dominant negative effects in transfected animals. Donor egg IVF was the sole effective treatment; however, no viable pregnancies were documented in patients with pathogenic mutations of TUBB8 or KIF11. TUBB8, KIF11, and CKAP5 are essential for safeguarding oocyte meiotic competence and early embryonic development at the molecular level. Genetic differences in these genes disrupt microtubule dynamics and spindle assembly, resulting in various aspects of oocyte maturation and fertilization. Functional validation underscores the necessity of routine genetic screening for women experiencing unresolved IVF failure, as it substantiates their causal role in infertility. Future therapeutic avenues in ART may be enhanced by tailored counseling and innovative rescue methodologies like as gene therapy. Full article

Autism spectrum disorder (ASD) encompasses a range of neurodevelopmental conditions characterized by impairments in social abilities and communication. Studying appropriate animal models can enhance our understanding of the neural mechanisms underlying these conditions, potentially leading to improved treatment and intervention strategies. Modeling impairments in linguistic development and vocal communication caused by autism had been a challenging goal for a long time. Prenatal valproic acid (VPA) treatment has been successfully used to induce ASD-like behavioral symptoms in several vertebrate species including birds. Applying VPA-treatment on songbirds, therefore, offers a promising research paradigm to model ASD. In this study, we investigated the effect of embryonic VPA treatment on song learning in the highly social zebra finch (Taeniopygia guttata). Fertilized eggs were injected with either 0.45 µmol VPA or a saline solution on day 9 of incubation, and hatchlings were allowed to stay with their parents until day 35 post-hatching to facilitate song learning from the father. Once male offsprings reached adulthood, their songs were recorded and compared to those of their fathers. VPA-exposed males exhibited significantly greater similarity to their fathers’ songs compared to control males (74% vs. 31%, respectively), suggesting a reduced ability to modify and develop their own vocal patterns as subadults. Additionally, they showed higher entropy in their songs compared to controls (−1.4 vs. −1.7), indicating more disorganized vocalizations. These findings suggest that prenatal VPA exposure disrupts typical song learning and vocal development in zebra finches, likely by affecting neural mechanisms involved in vocal learning and crystallization of the songs. Our study suggests VPA treatment in songbirds provides a useful tool to model and investigate linguistic developmental disorders related to ASD in humans. Full article

Summer high temperatures (27–38 °C, more than 7 days) readily induce heat stress in late-laying broiler breeders, which impedes offspring growth and development. This study aimed to provide a scientific basis for improving the offspring development of late-laying broiler breeders during summer. Six hundred fertilized eggs from 50-week-old LiFeng broiler breeders were divided into five treatment groups (non-injected, NaCl-injected, 6 mg/egg L-arginine-injected, 3.5 mg/egg L-methionine-injected, 8.4 mg/egg L-leucine-injected), with six replicates per group and 20 eggs per replicate. Embryos were incubated for 21 days and chicks raised for 21 days post-hatch. Methionine injection significantly enhanced hatchability (+5.8%), increased daily chick weight gain (+8.8%), reduced serum urea nitrogen (−53.13%), decreased inflammatory cytokine levels, elevated antioxidant enzyme activities, lowered malondialdehyde content (−47.99%), and suppressed expression of inflammatory and apoptotic pathway genes. The comprehensive effect of methionine was the best among the three amino acids when injected into chicken embryos. Methionine promoted protein synthesis, enhanced antioxidant and anti-inflammatory capacities, and consequently improved chick growth performance. Full article

Natural mating colony cages are crucial in poultry breeding, yet breed-specific management requires further investigation. We evaluated the effects of sex ratios, stocking densities, and cohabitation age on Lohmann Pink-shell breeders’ performance. A total of 6126 birds were randomly allocated to experimental groups with varying ratios (1:8–1:13), densities (582–748 cm²/bird), and cohabitation ages (120/140 days), each containing six replicates. We monitored male mating frequencies at 50 weeks in 1:8 and 1:10 ratio groups. All 120-day-old groups showed delayed production onset and superior male weight compliance (p < 0.01), with reduced egg breakage and increased healthy chick output (p < 0.01). Lower stocking densities (748/694 cm²/bird) showed lower breakage rate and uniformity than 582 cm²/bird (p < 0.05). The 1:10 sex ratio achieved optimal egg production and fertilization rate (p < 0.05). Male mating peaked between 16:00 and 18:00. Optimal parameters were 120-day age of cohabitation, 694 cm²/bird density, and 1:10 sex ratio, providing theoretical guidance for natural mating colony cage development in layer breeding. Full article

Mammalian fertilization is triggered by a series of calcium (Ca²⁺) oscillations that are essential for egg activation and successful embryo development. It is widely accepted that Phospholipase C zeta (PLCζ) is the sperm-derived factor that triggers these oscillations, initiating egg activation through the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP₂) into inositol 1,4,5-trisphosphate (IP₃) and diacylglycerol (DAG), leading to Ca²⁺ release. Several studies have reported a number of PLCζ mutations associated with polyspermy, egg activation failure and early embryonic arrest. Herein, six infertility-linked PLCζ mutations (I120M, L246F, L277P, S350P, A384V and M578T) spanning different domains of PLCζ were selected for characterization through in vivo assessment of their Ca²⁺-oscillation-inducing activities and complementary in silico analysis. Our data revealed that five of the investigated PLCζ mutants exhibited reduced or complete loss of in vivo Ca²⁺-oscillation-inducing activity, with the exception of the L277P, which resulted in increased frequency and duration of Ca²⁺ oscillations. Molecular modeling of PLCζ mutants was consistent with the in vivo characterization, revealing that most mutations have a deleterious effect on the structural stability. For the first time, we provide evidence that a gain-of-function PLCζ mutation may be a cause of fertilization failure in humans. Our findings suggest that PLCζ enzymatic activity must operate within an optimal range to ensure successful egg activation and early embryonic development. Additionally, we demonstrate the essential role of all PLCζ domains in maintaining the Ca²⁺ oscillation-inducing activity in eggs and the importance of PLCζ functionality in human fertilization. Full article

Rooster behavior and activity are critical for egg fertility and hatchability in broiler and layer breeder houses. Desirable roosters are expected to have good leg health, reach sexual maturity, be productive, and show less aggression toward females during mating. However, not all roosters are desirable, and low-productive roosters should be removed and replaced. The objectives of this study were to apply an object detection model based on deep learning to identify hens and roosters based on phenotypic characteristics, such as comb size and body size, in a cage-free (CF) environment, and to compare the performance metrics among the applied models. Six roosters were mixed with 200 Lohmann LSL Lite hens during the pre-peak phase in a CF research facility and were marked with different identifications. Deep learning methods, such as You Only Look Once (YOLO) models, were innovated and trained (based on a comb size of up to 2500 images) for the identification of male and female chickens based on comb size and body features. The performance matrices of the YOLOv5u and YOLOv11 models, including precision, recall, mean average precision (mAP), and F1 score, were statistically compared for hen and rooster detection using a one-way ANOVA test at a significance level of p < 0.05. For rooster detection based on comb size, YOLOv5lu, and YOLOv11x variants performed the best among the five variants of each model, with YOLOv5lu achieving a precision of 87.7%, recall of 56.3%, and mAP@0.50 of 60.1%, while YOLOv11x achieved a precision of 86.7%, recall of 65.3%, and mAP@0.50 of 61%. For rooster detection based on body size, YOLOv5xu, and YOLOv11m outperformed other variants, with YOLOv5xu achieving a precision of 88.9%, recall of 77.7%, and mAP@0.50 of 82.3%, while YOLOv11m achieved a precision of 89.0%, recall of 78.8%, and mAP@0.50 of 82.6%. This study provides a reference for automatic rooster monitoring based on comb and body size and offers further opportunities for tracking the activities of roosters in a poultry breeder farm for performance evaluation and genetic selection in the future. Full article

Thermal manipulation (TM) during embryogenesis is a promising non-pharmacological strategy to enhance physiological resilience in broiler chickens. This study evaluated the impact of thermal conditioning of fertile eggs on growth performance, inflammatory responses, and molecular stress markers following a post-hatch lipopolysaccharide (LPS) challenge. Fertilized eggs (average weight 62 ± 3 g) were obtained from 35-week-old Indian River broiler breeder hens. A total of 720 eggs were randomly assigned to either the control group (n = 360) or the TM group (n = 360), with each group consisting of two replicates of 180 eggs. Control eggs were maintained under standard incubation conditions (37.8 °C, 56% RH), while TM eggs were subjected to elevated temperature (38.8 °C, 65% RH) for 18 h daily from embryonic day 10 to 18. On post-hatch day 15, control and TM groups were administered either saline or LPS via intraperitoneal (IP) injection. Body weight and temperature, internal organ weights, and splenic mRNA expression levels of inflammatory cytokines, toll-like receptors, transcription factors, and heat shock proteins were assessed. TM did not alter hatchability (p = 0.633), but significantly shortened hatch time (p < 0.05) and improved feed efficiency (p < 0.05). While LPS induced marked inflammatory responses in all birds, those subjected to TM exhibited attenuated proinflammatory cytokine expression, enhanced anti-inflammatory signaling, and differential regulation of stress-associated genes, including nuclear factor kappa B (NF-κB), heat shock protein 70 (HSP70), and heat shock factors (HSFs). These findings suggest that TM during incubation promotes a more regulated immune response and improved stress adaptation post-hatch. This approach offers a potential antibiotic-free intervention to enhance broiler health, performance, and resilience under immunological stress. Full article

Rising global temperatures challenge poultry production by disrupting the cecal microbiota, which is essential for chicken health. Thermal manipulation (TM) during embryogenesis is a potential strategy to enhance thermotolerance in broilers. This study examined TM’s effects on the cecal microbiome, body weight (BW), and body temperature (BT) under chronic heat stress (CHS). Fertile Indian River eggs (n = 800) were incubated under control (37.8 °C, 56% RH) or TM conditions (39 °C, 65% RH for 18 h per day from embryonic day 10 to 18). On post-hatch day 18, male chicks were assigned to either CHS (35 ± 0.5 °C for five days) or thermoneutral conditions (24 ± 0.5 °C). The CHS-TM group showed a significantly higher BW than the CHS-CON group (p < 0.05). Under thermoneutral conditions, TM chicks had a lower BT on day 1 (p < 0.05), while the CHS-TM group exhibited a non-significant BT reduction compared to the CHS-CON group under heat stress (p > 0.05). An analysis of the gut microbiome showed that the beta diversity analysis (PERMANOVA, p < 0.05) indicated distinct microbial shifts. Firmicutes and Bacteroidota dominated the phylum level, with CHS increased Bacilli and Lactobacillus while reducing Lachnospirales in the CHS-TM group. These findings suggest that TM modulates gut microbiota and mitigates BW loss, offering a potential strategy to enhance broilers’ resilience to heat stress. 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