Search Results (76)

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

For nearly three decades, interspecies somatic cell nuclear transfer (iSCNT) has been explored as a potential tool for cloning, regenerative medicine, and wildlife conservation. However, developmental inefficiencies remain a major challenge, largely due to persistent barriers in nucleocytoplasmic transport, mitonuclear communication, and epigenome crosstalk. This review synthesized peer-reviewed English articles from PubMed, Web of Science, and Scopus, spanning nearly three decades, using relevant keywords to explore the molecular mechanisms underlying iSCNT inefficiencies and potential improvement strategies. We highlight recent findings deepening the understanding of interspecies barriers in iSCNT, emphasizing their interconnected complexities, including the following: (1) nucleocytoplasmic incompatibility may disrupt nuclear pore complex (NPC) assembly and maturation, impairing the nuclear transport of essential transcription factors (TFs), embryonic genome activation (EGA), and nuclear reprogramming; (2) mitonuclear incompatibility could lead to nuclear and mitochondrial DNA (nDNA-mtDNA) mismatches, affecting electron transport chain (ETC) assembly, oxidative phosphorylation, and energy metabolism; (3) these interrelated incompatibilities can further influence epigenetic regulation, potentially leading to incomplete epigenetic reprogramming in iSCNT embryos. Addressing these challenges requires a multifaceted, species-specific approach that balances multiple incompatibilities rather than isolating a single factor. Gaining insight into the molecular interactions between the donor nucleus and recipient cytoplast, coupled with optimizing strategies tailored to specific pairings, could significantly enhance iSCNT efficiency, ultimately transforming experimental breakthroughs into real-world applications in reproductive biotechnology, regenerative medicine, and species conservation. Full article

Currently, the efficiency of somatic cell nuclear transfer (SCNT) technology is relatively low, primarily owing to reprogramming abnormalities in donor cells or reconstructed embryos. Using histone deacetylase inhibitor (HDACi) to artificially alter the epigenetic modifications of donor cells and improve the reprogramming ability of reconstructed embryos is effective in improving nuclear transfer efficiency. In this study, we used Albas cashmere goat cells as donor cells, treated them with Scriptaid, and constructed embryos using SCNT. The results suggest that donor cell treatment with Scriptaid significantly increased the cellular histone acetylation modification level, perturbed the expression of the pluripotency molecule NANOG, altered the reprogramming ability of embryos, and increased the developmental rate of SCNT-reconstructed embryos. Scriptaid inhibited donor cell proliferation, induced apoptosis, and blocked the G0/G1 phase of the cell cycle. These results provide a new research direction for improving SCNT efficiency and a new perspective in the fields of regenerative medicine, agriculture, and animal husbandry. Full article

Donkeys and mules have historically played an important role in agriculture and are now gaining recognition for their contributions to animal conservation, milk production, tourism, and equid-assisted services. However, their distinctive reproductive challenges pose obstacles to breeding management. As a result, the application of assisted reproductive technologies (ARTs) could help address these challenges, enhancing their roles in both traditional and emerging industries. This review examines the current and emerging in vitro techniques for breeding donkeys and mules. Key methodologies such as sperm cryopreservation, innovative sperm preservation technologies, embryo transfer, ovum pick-up (OPU), oocyte maturation, and vitrification are discussed, emphasizing their importance in optimizing ARTs. Advances in in vitro embryo production technologies such as in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and somatic cell nuclear transfer (SCNT) are reviewed, with particular attention to its success in producing the first donkey and mule blastocysts or foals. Despite significant progress in the last decade, standardization of protocols for gamete conservation and embryo transfer are still required in long-ear equids. Advancing these technologies in combination with established in vitro embryo production could significantly improve reproductive outcomes and enhance the genetic management of donkey and mule populations. Full article

A time-lapse live embryo monitoring system provides a powerful approach to recording dynamic developmental events of cultured embryos in detail. By obtaining continuous short-interval images, blastocyst formation can be predicted and embryos can be selected. The objective of this study was to investigate the morphokinetic parameters of fishing cat–domestic cat interspecies somatic cell nuclear transfer (iSCNT) embryos from one-cell to blastocyst stages, and in particular, the cleavage patterns of the first division in iSCNT and IVF embryos, as these play a central role in euploidy. Domestic cat in vitro fertilization (IVF) embryos were set up as controls. The results show that morula and blastocyst development rates were significantly lower in the iSCNT embryos compared to their IVF counterparts. All earlier time points of embryonic development before the onset of blastulation in the iSCNT embryos were significantly delayed when compared with their IVF counterparts. In iSCNT, normal embryos (defined as those that developed to the blastocyst stage) took a longer time to reach the morula stage, and these morulas were more likely to undergo compaction, compared to their arrested embryo counterparts. Direct cleavage in the first division is a morphological aberration, and was seen with greater prevalence in iSCNT embryos than control IVF embryos; these aberrant embryos displayed a significantly lower blastocyst development rate than embryos that had undergone normal cleavage. In conclusion, the morphokinetic parameters of fishing cat–domestic cat iSCNT embryos at early stages could be used to predict their potential for development to the blastocyst stage. A time-lapse imaging system is potentially a powerful tool for selecting early embryos with developmental potential for transfer, and hence, for improving feline iSCNT efficiency. Full article

Polyunsaturated fatty acids (PUFAs) such as linoleic acid (18:2, n-6) and α-linolenic acid (18:3, n-3) are essential for the growth, development, and well-being of mammals. However, most mammals, including humans, cannot synthesize n-3 and n-6 PUFAs and these must be obtained through diet. The beneficial effect of converting n-6 polyunsaturated fatty acids (n-6 PUFAs) into n-3 polyunsaturated fatty acids (n-3 PUFAs) has led to extensive research on the flax fatty acid desaturase 3 (Fad3) gene, which encodes fatty acid desaturase. Still, the plant-derived Fad3 gene is used much less in transgenic animals than the Fat-1 gene from Caenorhabditis elegans. To address this problem, we used somatic cell nuclear transfer (SCNT) technology to create codon-optimized Fad3 transgenic cattle. Gas chromatographic analysis showed that the n-3 PUFA content of transgenic cattle increased significantly, and the ratio of n-6 PUFAs to n-3 PUFAs decreased from 3.484 ± 0.46 to about 2.78 ± 0.14 (p < 0.05). In conclusion, Fad3 gene knock-in cattle are expected to improve the nutritional value of beef and can be used as an animal model to study the therapeutic effects of n-3 PUFAs in various diseases. Full article

Somatic cell nuclear transfer (SCNT) has great potential for the replication of high-commercial-value animals, threatened wild species for conservation purposes, and transgenic animals for biomedical purposes. However, SCNT has a low success rate due to intrinsic factors of the technique itself, which leads to low rates of embryonic development and epigenetic alterations in cloned embryos. The objective of this study was to evaluate the effect of OF–UF on the intracellular concentrations of ROS and GSH and the development of cloned and parthenogenetic Ovis aries embryos. The results do not show a beneficial effect on the development of parthenogenetic and cloned embryos at concentrations of 0.5% OF–UF. Furthermore, at 1% OF–UF, an adverse effect was observed in cloned embryos at the blastocyst stage and 2% OF and UF in parthenogenetic embryos during the first divisions. Decreases in ROS and GSH levels were observed in the parthenogenetic blastocysts treated with 1% OF–UF, but not in the clones, in which a higher concentration of GSH and a similar concentration of ROS were observed. No effect of OF–UF was observed on embryonic development and redox balance in sheep embryos cloned via handmade cloning. Full article

A major factor limiting the development of somatic cell nuclear transfer (SCNT) technology is the low success rate of pregnancy, mainly due to placental abnormalities disrupting the maternal-fetal balance during pregnancy. Although there has been some progress in research on the abnormal enlargement of cloned bovine placenta, there are still few reports on the direct regulatory mechanisms of enlarged cloned bovine placenta tissue. In this study, we conducted sequencing and analysis of transcriptomics, proteomics, and metabolomics of placental tissues from SCNT cattle (n = 3) and control (CON) cattle (n = 3). The omics analysis results indicate abnormalities in biological functions such as protein digestion and absorption, glycolysis/gluconeogenesis, the regulation of lipid breakdown, as well as glycerolipid metabolism, and arginine and proline metabolism in the placenta of SCNT cattle. Integrating these analyses highlights critical metabolic pathways affecting SCNT cattle placenta, including choline metabolism and unsaturated fatty acid biosynthesis. These findings suggest that aberrant expressions of genes, proteins, and metabolites in SCNT placentas affect key pathways in protein digestion, growth hormone function, and energy metabolism. Our results suggest that abnormal protein synthesis, growth hormone function, and energy metabolism in SCNT bovine placental tissues contribute to placental hypertrophy. These findings offer valuable insights for further investigation into the mechanisms underlying SCNT bovine placental abnormalities. Full article

Convenient and consistent phase convention is important in the construction of the hadronic Lagrangian. However, the importance of phase convention has been overlooked for a long time, and the sources of different conventions are never explicitly addressed. This obscure situation can cause mistakes and misinterpretations in hadron physics. In this paper, we systematically analyze and compare the flavor $S{U}_3$ phase conventions from the perspective of the quark model. All sources that could lead to different conventions are pointed out and carefully studied. With the tool of the quark model, we also clarify some misconceptions and demonstrate a consistent way to incorporate different conventions. Full article

Somatic cell nuclear transfer (SCNT) technology holds great promise for livestock industry, life science and human biomedicine. However, the development and application of this technology is limited by the low developmental potential of SCNT embryos. The developmental competence of cloned embryos is influenced by the energy metabolic status of donor cells. The purpose of this study was to investigate the effects of CPI, an oxidative phosphorylation inhibitor, on the energy metabolism pathways of pig fibroblasts and the development of subsequent SCNT embryos. The results showed that treatment of porcine fibroblasts with CPI changed the cellular energy metabolic pathways from oxidative phosphorylation to glycolysis and enhanced the developmental ability of subsequent SCNT embryos. The present study establishes a simple, new way to improve pig cloning efficiency, helping to promote the development and application of pig SCNT technology. Full article

Anode materials play a crucial role in the performance of microbial fuel cells (MFCs) in terms of power output. In this study, carbon nanotube (CNT)/polyaniline (PANI)/chitosan (CS) composites were prepared on a porous sponge matrix. The high electrical conductivity of CNTs, the capacitive behavior of PANI, and the biocompatibility of CS were leveraged to enhance the electricity generation and energy storage capabilities of MFCs. Experimental results demonstrated that the MFC with the modified anode achieved a maximum power density of 7902.4 mW/m³. Moreover, in the charging–discharging test, the stored electricity of the S/CNT/PANI/CS anode was 16.38 times that of the S/CNT anode when both the charging and discharging times were 30 min. High-throughput sequencing revealed that the modified composite anode exhibited remarkable biocompatibility and selective enrichment of electrogenic bacteria. Overall, this study presents a novel approach for developing composite MFC anode materials with energy storage functionality. Full article

Auckland Island pigs represent an inbred population of feral pigs isolated on the sub-Antarctic island for over 100 years. The animals have been maintained under pathogen-free conditions in New Zealand; they are well characterized virologically and have been used as donor sources in first clinical trials of porcine neonatal islet cell transplantation for the treatment of human diabetes patients. The animals do not carry any of the xenotransplantation-relevant viruses, and in the first clinical trials, no porcine viruses, including porcine endogenous retroviruses (PERVs) were transmitted to the human recipients. PERVs pose a special risk in xenotransplantation, since they are part of the pig genome. When the copy number of PERVs in these animals was analyzed using droplet digital PCR and primers binding to a conserved region of the polymerase gene (PERVpol), a copy number typical for Western pigs was found. This confirms previous phylogenetic analyses of microsatellites as well as mitochondrial analyses showing a closer relationship to European pigs than to Chinese pigs. When kidney cells from very young piglets were analyzed, only around 20 PERVpol copies were detected. Using these cells as donors in somatic cell nuclear transfer (SCNT), animals were born showing PERVpol copy numbers between 35 and 56. These data indicate that Auckland Island pigs have a similar copy number in comparison with other Western pig breeds and that the copy number is higher in adult animals compared with cells from young piglets. Most importantly, PERV-C-free animals were selected and the absence of an additional eight porcine viruses was demonstrated. Full article

Carbon nanotube (CNT)-based networks have wide applications, in which structural design and control are important to achieve the desired performance. This paper focuses on the mechanism behind the structure-dependent mechanical performance of a CNT-based hierarchical network, named a super carbon nanotube (SCNT), which can provide valuable guidance for the structural design of CNT-based networks. Through molecular dynamic (MD) simulations, the mechanical properties of the SCNTs were found to be affected by the arrangement, length and chirality of the CNTs. Different CNT arrangements cause variations of up to 15% in the ultimate tensile strains of the SCNTs. The CNT length determines the tangent elastic modulus of the SCNTs at the early stage. Changing the CNT chirality could transform the fracture modes of the SCNT from brittle to ductile. The underlying mechanisms were found to be associated with the deformation mode of the SCNTs. All the SCNTs undergo a top-down hierarchical deformation process from the network-level angle variations to the CNT-level elongations, but some vital details vary, such as the geometrical parameters. The CNT arrangement induces different deformation contributors of the SCNTs. The CNT length affects the beginning point of the CNT elongation deformation. The CNT chirality plays a crucial role in the stability of the junction’s atomic topology, where the crack propagation commences. Full article

The preparation of semiconducting carbon nanotube (s-CNT) thin films by solution processing has become the mainstream approach nowadays. However, residual polymers are always inevitable during the sorting of s-CNTs in solution. These residual polymers will degrade the electrical properties of the CNTs. Although several post-treatment approaches have been reported to be effective in improving the performance of the device, there is no deep analysis and comprehensive comparison of these approaches, so there is no overall guidance on the optimum treatment of CNTs for performance improvement. In this work, we characterize CNT thin film with three post-treatment methods, including annealing (A), yttrium oxide coating and decoating (Y), and annealing combined with YOCD (A + Y), and evaluate and compare the performance of Field Effect Transistors (FETs) based on the above mentioned CNT thin film. The result shows that the CNT thin film treated by the A + Y method is the clearest and flattest; the average roughness determined from the overall AFM image is reduced by 28% (from 1.15–1.42 nm (O) to 0.826–1.03 nm (A + Y)), which is beneficial in improving the device contact quality, uniformity, and stability. The on-state current (I_on) of the FETs with CNTs treated by A, Y, and A + Y is improved by 1.2 times, 1.5 times, and 1.75 times, respectively, compared with that of FETs fabricated by untreated CNTs (O for original CNTs), indicating that the A + Y is the optimum post-treatment method for the A + Y and combines the effect of the other two methods. Accordingly, the contact and channel resistance (2R_c and R_ch) of the CNT FETs treated by different post-treatment methods including A, Y, and A + Y is reduced by 0.18/0.24 times, 0.37/0.32 times, and 0.48/0.41 times, respectively. The ratio of improvement in device performance is about 1:2 for the contact and channel sections for a transistor with a 500 nm channel length, and this ratio will go up further with the channel length scaling; together with the decay in the channel resistance optimization effect in the scaling device, it is necessary to adopt more methods to effectively reduce the contact resistance further. Full article

Although the efficiency of cloning remains very low, this technique has become the most reliable way to produce transgenic pigs. However, the high rate of abnormal offspring such as an enlarged tongue lowers the cloning efficiency by reducing the early survivability of piglets. Thus, the present study was conducted to identify the characteristics of the enlarged tongue from cloned piglets by histologic and transcriptomic analysis. As a result, it was observed that the tissues from enlarged tongues (n = 3) showed isolated and broken muscle bundles with wide spaces while the tissues from normal tongues (n = 3) showed the tight connection of muscle bundles without space by histological analysis. Additionally, transmission electron microscopy results also showed the formation of isolated and broken muscle bundles in enlarged tongues. The transcriptome analysis showed a total of 197 upregulated and 139 downregulated genes with more than 2-fold changes in enlarged tongues. Moreover, there was clear evidence for the difference between groups in the muscle system process with high relation in the biological process by gene ontology analysis. The analysis of the Kyoto Encyclopedia of Gene and Genomes pathway of differentially expressed genes indicated that the pentose phosphate pathway, glycolysis/gluconeogenesis, and glucagon signaling pathway were also involved. Conclusively, our results could suggest that the abnormal glycolytic regulation may result in the formation of an enlarged tongue. These findings might have the potential to understand the underlying mechanisms, abnormal development, and disease diagnosis in cloned pigs. Full article