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(1) Background: Improving feed efficiency and the vitality of the reproductive system in the late stage of the egg-laying period is of great significance for prolonging the egg-laying cycle and improving egg quality. In the present study, a new flavonoid, which was extracted from kudzu leaf, was chosen to investigate its effects on the productive performance and egg quality of late-laying hens. (2) Methods: A total of 360 500-day-old Hy-Line Brown layer hens were randomly divided into a control treatment group (no KLF supplementation), and groups that received 0.2%, 0.4%, 0.6%, 0.8%, and 1.0% KLF supplement treatments. Each treatment contained 6 replicates, with 10 hens in each replicate. Productive performance metrics, including the daily egg production, egg weight, the number of deformed eggs, egg quality, egg density, egg shape index, eggshell strength, yolk color, and the Haugh unit, were meticulously recorded for each replicate. Furthermore, microbial communities and hypothalamus gene expressions were investigated based on the results of the productive performance and egg quality. (3) Results: KLF supplementation significantly decreased the deformity rate while significantly increasing the eggshell strength in the finishing phase afterward (p < 0.05). Specifically, hens supplemented with 0.6% KLF possessed the lowest deformed egg rate. KLF supplementation significantly increased the relative abundances of Bifidobacterium sp., Blautia sp., Lactococcus sp., and Lactobacillus sp., while significantly decreasing Parasutterella sp. and Escherichia-Shigella sp. (p < 0.05). Furthermore, the interactive analysis showed the hypothalamus gene expression mainly interacted with probiotics, such as Bifidobacterium sp. and Lactobacillus sp., through ribosome biogenesis, nucleocytoplasmic transport, and cAMP signaling pathways. (4) Conclusions: The findings of the present study indicate that KLF supplementation significantly proliferated probiotics, such as Bifidobacterium and Lactobacillus, which may have further interacted with hypothalamus genes, thus decreasing the deformity rate while increasing eggshell strength in the finishing phase.

The purpose of this study was to investigate the effects of dried blueberry pomace (BP) and pineapple pomace (PP) on the growth performance and meat quality of broiler chickens. A total of 240 1-day-old Ross 308 broiler chickens were randomly divided into 3 groups, with 10 replicates per treatment group and 8 birds per replicate (4 males and 4 females). The three groups were the control (CON) group, the 3% BP group, and 3% PP group. The entire trial period lasted 42 days. The results show that the average daily feed intake, average daily gain, and feed-to-gain ratio of the BP group and the PP group were not significantly different from those in the CON group (p > 0.05). Adding BP to the diet significantly reduced the proportion of liver and giblets (p < 0.05). Adding PP to the diet significantly reduced the proportion of liver, while the proportion of gizzard significantly increased (p < 0.05). The pH24h and L* of breast muscles were significantly lower in the PP group than in the CON group (p < 0.05). The water-holding capacity of the leg muscles in the BP group and the PP group was significantly lower than that in the CON group (p < 0.05). The crude protein content of breast muscle and the ether extract content of leg muscle in the BP group were significantly lower than those in the CON group (p < 0.05). In conclusion, the addition of 3% BP and PP to broiler chickens’ diets had no adverse effects on growth performance or meat quality.

Abstract Background Regulation of transcription depends on interactions between cis-regulatory elements (CREs) and regulatory proteins. Active CREs are imbedded in open chromatin that are accessible to nucleases. Several techniques, including DNase-seq, which is based on nuclease DNase I, and ATAC-seq, which is based on transposase Tn5, have been widely used to identify genomic regions associated with open chromatin. These techniques have played a key role in dissecting the regulatory networks in gene expression in both animal and plant species. Results We develop a technique, named MNase hypersensitivity sequencing (MH-seq), to identify genomic regions associated with open chromatin in Arabidopsis thaliana. Genomic regions enriched with MH-seq reads are referred as MNase hypersensitive sites (MHSs). MHSs overlap with the majority (~ 90%) of the open chromatin identified previously by DNase-seq and ATAC-seq. Surprisingly, 22% MHSs are not covered by DNase-seq or ATAC-seq reads, which are referred to “specific MHSs” (sMHSs). sMHSs tend to be located away from promoters, and a substantial portion of sMHSs are derived from transposable elements. Most interestingly, genomic regions containing sMHSs are enriched with epigenetic marks, including H3K27me3 and DNA methylation. In addition, sMHSs show a number of distinct characteristics including association with transcriptional repressors. Thus, sMHSs span distinct classes of open chromatin that may not be accessible to DNase I or Tn5. We hypothesize that the small size of the MNase enzyme relative to DNase I or Tn5 allows its access to relatively more condensed chromatin domains. Conclusion MNase can be used to identify open chromatin regions that are not accessible to DNase I or Tn5. Thus, MH-seq provides an important tool to identify and catalog all classes of open chromatin in plants.

The genetic structure and evolutionary relationship of Dulong chicken with other native Chinese species remained unclear. In this study, the mitochondrial control region was analyzed in total of 343 samples comprising 59 from Dulong chicken and 284 from 8 other Chinese local breeds revealed 51 mutation sites that defined 42 haplotypes. The maximum genetic variation was observed between the Shimian caoke and Pengxian yellow chickens. Phylogenetic analysis revealed that these local chickens mainly scatter in two southwestern clades. Dulong chickens have close relationship with other native chicken. Finding of this study suggests a single matrilineal lineage of indigenous Dulong chickens.

In this paper, a novel method to actively damp the powertrain vibration by utilizing a flywheel integrated starter generator (FISG) is proposed and validated on the testbench. A more light-weighted, economical, and compact hybrid powertrain devoid of clutches or dampers is built by replacing its flywheel with the ISG rotor. Motor torque having the opposite phase of the engine torque is applied to reduce the vibration. As opposed to the passive methods, which usually make use of the inertial and/or the damping properties of the components to absorb the vibration, this active approach is defined as active damping. Firstly, active damping is proved to be theoretically feasible by simulation based on an engine torque observer. To get the practical-application-oriented motor torque waveform, the observer torque is then processed by considering some realistic factors, such as the motor's response delay and the torque demand limit at MCU (Motor Control Unit), and is finally simplified as the rectangular waveform by off-line simulation. Secondly, an algorithm operating on the original resolver aimed at calculating the real-time crank position is proposed and programmed directly in the MCU. Finally, active damping is realized online utilizing a feedforward method by programming the crank-torque table in MCU. Experiments in both stable and transient conditions are conducted. Results show that active damping can attenuate the vibration effectively, especially over low speed and load ranges. The speed fluctuation range and the cyclic squared angular acceleration can be reduced by 79.7% and 89.7% respectively at 700 rpm when cranking. The crank vibration in transient conditions, including dragging and free deceleration, can also be suppressed, showing potential to realize fast and quiet engine start and halt.

Abstract Background There are hundreds of phenotypically distinguishable domestic chicken breeds or lines with highly specialized traits worldwide, which provide a unique opportunity to illustrate how selection shapes patterns of genetic variation. There are many local chicken breeds in China. Results Here, we provide a population genome landscape of genetic variations in 86 domestic chickens representing 10 phenotypically diverse breeds. Genome-wide analysis indicated that sex chromosomes have less genetic diversity and are under stronger selection than autosomes during domestication and local adaptation. We found an evidence of admixture between Tibetan chickens and other domestic population. We further identified strong signatures of selection affecting genomic regions that harbor genes underlying economic traits (typically related to feathers, skin color, growth, reproduction and aggressiveness) and local adaptation (to high altitude). By comparing the genomes of the Tibetan and lowland fowls, we identified genes associated with high-altitude adaptation in Tibetan chickens were mainly involved in energy metabolism, body size maintenance and available food sources. Conclusions The work provides crucial insights into the distinct evolutionary scenarios occurring under artificial selection for agricultural production and under natural selection for success at high altitudes in chicken. Several genes were identified as candidates for chicken economic traits and other phenotypic traits.

The bursa of Fabricius (BF) is a target organ for various pathogenic microorganisms; however, the genes that regulate BF development and decline have not been fully characterized. Therefore, in this study, histological sections of the BF were obtained from black-boned chickens at 7 (N7), 42 (N42), 90 (N90) and 120 days (N120) of age, and the differential expression and expression trends of the BF at different stages were analyzed by transcriptome analysis. The results showed that the growth of the BF progressively matured with age, followed by gradual shrinkage and disappearance. Transcriptome differential analysis revealed 5914, 5513, 4575, 577, 530 and 66 differentially expressed genes (DEG) in six different comparison groups: N7 vs. N42, N7 vs. N90, N7 vs. N120, N42 vs. N90, N42 vs. N120 and N90 vs. N120, respectively. Moreover, we performed transcriptomic analysis of the time series of BF development and identified the corresponding stages of biological process enrichment. Finally, quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the expression of the 16 DEGs during bursal growth and development. These results were consistent with the transcriptome results, indicating that they reflect the expression of the BF during growth and development and that these genes reflect the characteristics of the BF at different times of development and decline. These findings reflect the characteristics of the BF at different time intervals.

The liver is the major organ of lipid biosynthesis in the chicken. In laying hens, the liver synthesizes most of the yolk precursors and transports them to developing follicles to produce eggs. However, a systematic investigation of the long non-coding RNA (lncRNA) and mRNA transcriptome in liver across developmental stages is needed. Here, we constructed 12 RNA libraries from liver tissue during four developmental stages: juvenile (day 60), sexual maturity (day 133), peak laying (day 220), and broodiness (day 400). A total of 16,930 putative lncRNAs and 18,260 mRNAs were identified. More than half (53.70%) of the lncRNAs were intergenic lncRNAs. The temporal expression pattern showed that lncRNAs were more restricted than mRNAs. We identified numerous differentially expressed lncRNAs and mRNAs by pairwise comparison between the four developmental stages and found that VTG2, RBP, and a novel protein-coding gene were differentially expressed in all stages. Time-series analysis showed that the modules with upregulated genes were involved in lipid metabolism processes. Co-expression networks suggested functional relatedness between mRNAs and lncRNAs; the DE-lncRNAs were mainly involved in lipid biosynthesis and metabolism processes. We showed that the liver transcriptome varies across different developmental stages. Our results improve our understanding of the molecular mechanisms underlying liver development in chickens.

Abstract Background Pigeon crop has the unique ability to produce a nutrient rich substance termed pigeon ‘milk’ (PM), which has functional resemblance with the mammalian milk. Previous researches have demonstrated that a large number of exosomes and exosomal miRNAs exist in mammalian milk, and many of them are associated with immunity, growth and development. However, to date, little is known about the exosomes and exosomal miRNAs in PM. Results In this study, we isolated the exosomes from PM and used small RNA sequencing to investigate the distribution and expression profiles of exosomal miRNAs. A total of 301 mature miRNAs including 248 conserved and 53 novel miRNAs were identified in five lactation stages i.e. 1d, 5d, 10d, 15d, and 20d. From these, four top 10 conserved miRNAs (cli-miR-21-5p, cli-miR-148a-3p, cli-miR-10a-5p and cli-miR-26a-5p) were co-expressed in all five stages. We speculate that these miRNAs may have important role in the biosynthesis and metabolism of PM. Moreover, similar to the mammalian milk, a significant proportion of immune and growth-related miRNAs were also present and enriched in PM exosomes. Furthermore, we also identified 41 orthologous miRNAs group (giving rise to 81 mature miRNA) commonly shared with PM, human, bovine and porcine breast milk. Additionally, functional enrichment analysis revealed the role of exosomal miRNAs in organ development and in growth-related pathways including the MAPK, Wnt and insulin pathways. Conclusions To sum-up, this comprehensive analysis will contribute to a better understanding of the underlying functions and regulatory mechanisms of PM in squabs.

The wild Rubus species R. coreanus, which is widely distributed in southwest China, shows great promise as a genetic resource for breeding. One of its outstanding properties is adaptation to high temperature and humidity. To facilitate its use in selection and breeding programs, we assembled de novo 179,738,287 R. coreanus reads (125 bp in length) generated by RNA sequencing from fruits at three representative developmental stages. We also used the recently released draft genome of R. occidentalis to perform reference-guided assembly. We inferred a final 95,845-transcript reference for R. coreanus. Of these genetic resources, 66,597 (69.5%) were annotated. Based on these results, we carried out a comprehensive analysis of differentially expressed genes. Flavonoid biosynthesis, phenylpropanoid biosynthesis, plant hormone signal transduction, and cutin, suberin, and wax biosynthesis pathways were significantly enriched throughout the ripening process. We identified 23 transcripts involved in the flavonoid biosynthesis pathway whose expression perfectly paralleled changes in the metabolites. Additionally, we identified 119 nucleotide-binding site leucine-rich repeat (NBS-LRR) protein-coding genes, involved in pathogen resistance, of which 74 were in the completely conserved domain. These results provide, for the first time, genome-wide genetic information for understanding developmental regulation of R. coreanus fruits. They have the potential for use in breeding through functional genetic approaches in the near future.

Luffa was evaluated as a potential energy crop. A considerable amount of luffa sponge biomass can be grown in a vertical direction with approximately 70% polysaccharide content and low lignin content. When concentrated H3PO4 was employed to pretreat luffa sponge, hemicelluloses were the most sensitive component, followed by cellulose and lignin. Hemicellulose solubilization and cellulose loss positively responded to the elevated temperature, time, H3PO4 concentration, and dosage for pretreatment. However, lignin solubilization was not affected greatly. Although the initial hydrolysis rate was accelerated by increasing pretreatment temperature, the final glucose conversion was reduced as temperature was raised higher than 50 °C. Prolonging pretreatment time was positively correlated to enzymatic digestibility. When H3PO4 concentration was lower than 80%, the final glucose conversion was increased with increasing H3PO4 concentration. Increasing H3PO4 concentration to 84% for pretreatment caused the final glucose conversion to decrease slightly, although the hydrolysis rate was initially accelerated. Additionally, an improvement of glucose conversion was obtained with increasing the substrate-to-phosphoric acid ratio. However, the improvement was not cost-effective, as the ratio was lower than 1-to-8.

Extensive and in-depth investigations of high-altitude adaptation have been carried out at the level of morphology, anatomy, physiology and genomics, but few investigations focused on the roles of microRNA (miRNA) in high-altitude adaptation. We examined the differences in the miRNA transcriptomes of two representative hypoxia-sensitive tissues (heart and lung) between yak and cattle, two closely related species that live in high and low altitudes, respectively. In this study, we identified a total of 808 mature miRNAs, which corresponded to 715 pre-miRNAs in the two species. The further analysis revealed that both tissues showed relatively high correlation coefficient between yak and cattle, but a greater differentiation was present in lung than heart between the two species. In addition, miRNAs with significantly differentiated patterns of expression in two tissues exhibited co-operation effect in high altitude adaptation based on miRNA family and cluster. Functional analysis revealed that differentially expressed miRNAs were enriched in hypoxia-related pathways, such as the HIF-1α signaling pathway, the insulin signaling pathway, the PI3K-Akt signaling pathway, nucleotide excision repair, cell cycle, apoptosis and fatty acid metabolism, which indicated the important roles of miRNAs in high altitude adaptation. These results suggested the diverse degrees of miRNA transcriptome variation in different tissues between yak and cattle, and suggested extensive roles of miRNAs in high altitude adaptation.

Flyability is the most discrepant trait between modern-day geese and their wild ancestors, and the degeneration of flyability is a key marker of the successful domestication of wild geese. In light of the relatively short history of domestic geese, intense artificial selection is thought to play an important role in the degeneration of flyability. However, the underlying mechanism behind this phenomenon has seldom been investigated. In this study, we applied a molecular evolutionary approach to the evaluation of partial breeds of domestic geese in order to look for genes involved in the selection pressure toward degeneration of flyability. The haplotype networks, pairwise fixation index (FST) values, and analysis of molecular variance results all clearly illustrated a population variance between Landes geese and partial Chinese domestic geese. We also detected signatures of positive artificial selection in the COX2 and COX3 genes, and related selection in the HBB gene. Our results support the independent origins of partial European domestic geese and Chinese domestic geese. In addition, both positive artificial selection and the relaxation of functional constraints appeared to play important roles in the degeneration of flyability in domestic geese.

Chicken is the most common poultry species and is important to human societies. Tibetan chicken (Gallus gallus domesticus) is a breed endemic to China that is distributed mainly on the Qinghai-Tibet Plateau. However, its origin has not been well characterized. In the present study, we sequenced partial mitochondrial DNA (mtDNA) control region of 239 and 283 samples from Tibetan and Sichuan indigenous chickens, respectively. Incorporating 1091 published sequences, we constructed the matrilineal genealogy of Tibetan chickens to further document their domestication history. We found that the genetic structure of the mtDNA haplotypes of Tibetan chickens are dominated by seven major haplogroups (A-G). In addition, phylogenetic and network analyses showed that Tibetan chickens are not distinguishable from the indigenous chickens in surrounding areas. Furthermore, some clades of Tibetan chickens may have originated from game fowls. In summary, our results collectively indicated that Tibetan chickens may have diverged from indigenous chickens in the adjacent regions and hybridized with various chickens.

To explore the effects of the mutations of ATP6 and ATP8 genes on energy metabolism and genetic structure, we sequenced the ATP6 and ATP8 genes of Ailuropoda melanoleuca. Our results showed that ATP8 is a conserved gene and ATP6 gene is positively selected during the evolution of the giant panda population with a low genetic diversity. Population expansion was observed in the giant panda group. The T179C mutation on Haplotype7 made the production of a potential phosphorylation site. This non-synonymous mutation may occur at the post-translational modification site that have a potential effect on the function of ATP synthase, related to the maintenance of body temperature of pandas at low metabolic rates.

Due to the increasing demand for producing chickens with high meat quality, there is a need to determine its mode of action on chicken meat quality traits across a wider age spectrum. In this study, five groups of 200 male Da-Heng meat type birds were reared until slaughter age of 60, 90, 120, 150, 180 days old and breast muscle performance, meat quality traits, and myofiber characteristics were evaluated. The larger body weight and breast weight of chicken are based on larger myofiber diameter and area, less myofiber density for the older birds than younger birds. There was an age effect on all meat quality traits of chicken breast muscle (p < 0.05). Older chickens often presented a higher pH, lower drip loss, higher shear force, darker, and redder breast meat. The correlation coefficients showed that myofiber characteristics played an important role in breast pH values, drip loss, and meat color (p < 0.05). Besides, significant correlations were also found between meat quality traits (p < 0.05). Further studies are needed to explore the biochemical character and potential molecular mechanism of chicken breast muscle to determine the factors that causes these age-related differences in meat quality in the current study.

MicroRNAs (miRNAs) play critical roles in many important biological processes, such as growth and development in mammals. Various studies of porcine muscle development have mainly focused on identifying miRNAs that are important for fetal and adult muscle development; however, little is known about the role of miRNAs in middle-aged muscle development. Here, we present a comprehensive investigation of miRNA transcriptomes across five porcine muscle development stages, including one prenatal and four postnatal stages. We identified 404 known porcine miRNAs, 118 novel miRNAs, and 101 miRNAs that are conserved in other mammals. A set of universally abundant miRNAs was found across the distinct muscle development stages. This set of miRNAs may play important housekeeping roles that are involved in myogenesis. A short time-series expression miner analysis indicated significant variations in miRNA expression across distinct muscle development stages. We also found enhanced differentiation- and morphogenesis-related miRNA levels in the embryonic stage; conversely, apoptosis-related miRNA levels increased relatively later in muscle development. These results provide integral insight into miRNA function throughout pig muscle development stages. Our findings will promote further development of the pig as a model organism for human age-related muscle disease research.

Host defense peptides (HDPs) play a critical role in innate immunity. Specific modulation of endogenous HDP synthesis by dietary compounds has been regarded as a novel approach to boost immunity and disease resistance in animal production. 1,25-dihydroxy vitamin D3 (1,25D3) is well known as a powerful HDP inducer in humans, but limited information about the effect of 1,25D3 on HDPs in poultry is available. Here, we sought to examine whether 1,25D3 could stimulate avian β-defensin (AvBD) expression in chickens. We used chicken embryo intestinal epithelial cells (CEIEPCs) and peripheral blood mononuclear cells (PBMCs) to study the effect of 1,25D3 on the expression of AvBDs. We observed that 1,25D3 is able to up-regulate the expression of several AvBDs in CEIEPCs and PBMCs, whereas it increased the amounts of AvBD4 mRNA in CEIEPCs only in the presence of lipopolysaccharide (LPS). On the other hand, LPS treatment not only inhibited the expression of CYP24A1 but also altered the expression pattern of VDR in CEIEPCs. Furthermore, AvBDs were not directly regulated by 1,25D3, as cycloheximide completely blocked 1,25D3-induced expression of AvBDs. Our observations suggest that 1,25D3 is capable of inducing AvBD gene expression and is a potential antibiotic alternative through augmentation of host innate immunity as well as disease control in chickens.

The genetic improvement of disease resistance in poultry continues to be a challenge. To identify candidate genes and loci responsible for these traits, genome-wide association studies using the chicken 60k high density single nucleotide polymorphism (SNP) array for six immune traits, total serum immunoglobulin Y (IgY) level, numbers of, and the ratio of heterophils and lymphocytes, and antibody responses against Avian Influenza Virus (AIV) and Sheep Red Blood Cell (SRBC), were performed. RT-qPCR was used to quantify the relative expression of the identified candidate genes. Nine significantly associated SNPs (P < 2.81E-06) and 30 SNPs reaching the suggestively significant level (P < 5.62E-05) were identified. Five of the 10 SNPs that were suggestively associated with the antibody response to SRBC were located within or close to previously reported QTL regions. Fifteen SNPs reached a suggestive significance level for AIV antibody titer and seven were found on the sex chromosome Z. Seven suggestive markers involving five different SNPs were identified for the numbers of heterophils and lymphocytes, and the heterophil/lymphocyte ratio. Nine significant SNPs, all on chromosome 16, were significantly associated with serum total IgY concentration, and the five most significant were located within a narrow region spanning 6.4kb to 253.4kb (P = 1.20E-14 to 5.33E-08). After testing expression of five candidate genes (IL4I1, CD1b, GNB2L1, TRIM27 and ZNF692) located in this region, changes in IL4I1, CD1b transcripts were consistent with the concentrations of IgY, while abundances of TRIM27 and ZNF692 showed reciprocal changes to those of IgY concentrations. This study has revealed 39 SNPs associated with six immune traits (total serum IgY level, numbers of, and the ratio of heterophils and lymphocytes, and antibody responses against AIV and SRBC) in Beijing-You chickens. The narrow region spanning 247kb on chromosome 16 is an important QTL for serum total IgY concentration. Five candidate genes related to IgY level validated here are novel and may play critical roles in the modulation of immune responses. Potentially useful candidate SNPs for marker-assisted selection for disease resistance are identified. It is highly likely that these candidate genes play roles in various aspects of the immune response in chickens.

Body composition and meat quality traits are important economic traits of chickens. The development of high-throughput genotyping platforms and relevant statistical methods have enabled genome-wide association studies in chickens. In order to identify molecular markers and candidate genes associated with body composition and meat quality traits, genome-wide association studies were conducted using the Illumina 60 K SNP Beadchip to genotype 724 Beijing-You chickens. For each bird, a total of 16 traits were measured, including carcass weight (CW), eviscerated weight (EW), dressing percentage, breast muscle weight (BrW) and percentage (BrP), thigh muscle weight and percentage, abdominal fat weight and percentage, dry matter and intramuscular fat contents of breast and thigh muscle, ultimate pH, and shear force of the pectoralis major muscle at 100 d of age. The SNPs that were significantly associated with the phenotypic traits were identified using both simple (GLM) and compressed mixed linear (MLM) models. For nine of ten body composition traits studied, SNPs showing genome wide significance (P

Abstract The D-genome progenitor of wheat (Triticum aestivum), Aegilops tauschii, possesses numerous genes for resistance to abiotic stresses, including drought. Therefore, information on the genetic architecture of A. tauschii can aid the development of drought-resistant wheat varieties. Here, we evaluated 13 traits in 373 A. tauschii accessions grown under normal and polyethylene glycol-simulated drought stress conditions and performed a genome-wide association study using 7,185 single nucleotide polymorphism (SNP) markers. We identified 208 and 28 SNPs associated with all traits using the general linear model and mixed linear model, respectively, while both models detected 25 significant SNPs with genome-wide distribution. Public database searches revealed several candidate/flanking genes related to drought resistance that were grouped into three categories according to the type of encoded protein (enzyme, storage protein, and drought-induced protein). This study provided essential information for SNPs and genes related to drought resistance in A. tauschii and wheat, and represents a foundation for breeding drought-resistant wheat cultivars using marker-assisted selection.

Wireless power transfer systems play an important role in the application of modern power supply technology. Wireless charging has been widely used in portable devices such as smartphones, laptops, and even some medical devices. Higher system efficiency can be achieved while reducing costs. This article describes the design of a capacitive power transfer (CPT) system using the Class-E amplifier method. When the capacitance of the coupling plate is small, the operation of Class-E amplifiers under Zero-Voltage-Switching (ZVS) conditions is very sensitive to their circuit parameters. By adding an additional capacitor to the Class-E amplifier, the coupling capacitance can be increased, resulting in better circuit performance. The high efficiency of the Class-E amplifier is verified by simulation and experimental results.