Population genetic variations of the matrix metalloproteinases-3 gene revealed hypoxia adaptation in domesticated yaks (Bos grunniens)

Xuezhi Ding,Chao Yang,Pengjia Bao,Xiaoyun Wu,Jie Pei,Ping Yan,Xian Guo 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.12

Objective: As an iconic symbol of Qinghai-Tibetan Plateau and of high altitude, yak are subjected to hypoxic conditions that challenge aerobic metabolism. Matrix metalloproteinases-3 (MMP3) is assumed to be a key target gene of hypoxia-inducible factor-1α that function as a master regulator of the cellular response to hypoxia. Therefore, the aim of this investigation was to identify the DNA polymorphism of MMP3 gene in domestic yak and to explore its possible association with high-altitude adaptation. Methods: The single-nucleotide polymorphisms (SNPs) genotyping and mutations scanning at the MMP3 locus were conducted in total of 344 individuals from four domestic Chinese yak breeds resident at different altitudes on the Qinghai-Tibetan Plateau, using high-resolution melting analysis and DNA sequencing techniques. Results: The novel of SNPs rs2381 A→G and rs4331 C→G were identified in intron V and intron VII of MMP3, respectively. Frequencies of the GG genotype and the G allele of SNP rs2381 A→G observed in high-altitude Pali yak were significantly higher than that of the other yak breeds resident at middle or low altitude (p<0.01). No significant difference was mapped for SNP rs4331 C→G in the yak population (p>0.05). Haplotype GC was the dominant among the 4 yak breeds, and Pearson correlation analysis showed that the frequencies of GC was significantly lower in Ganan (GN), Datong (DT), and Tianzhu white yaks (TZ) compared with Pali (PL) yak. The two SNPs were in moderate linkage disequilibrium in high-altitude yaks (PL) but not in middle-altitude (GN, DT) and low-altitude (TZ) yaks. Conclusion: These results indicate that MMP3 may have been subjected to positive selection in yak, especially that the SNP rs2381 A→G mutation and GC haplotypes might contribute to adaptation for yak in high-altitude environments.

A Hybrid CBPWM Scheme for Single-Phase Three-Level Converters

Shunliang Wang,Wensheng Song,Xiaoyun Feng,Rongjun Ding 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

A novel hybrid carrier-based pulse width modulation (CBPWM) scheme that combines unipolar and dipolar modulations is proposed for single-phase three-level rectifiers, which are widely applied in railway traction drive systems. The proposed CBPWM method can satisfy the volt-second balancing principle in the complete modulation index region through overmodulation compensation. The modulation scheme features two modulation modes: unipolar and dipolar. The operation range limits of these modulation modes can be modified by changing the separation coefficient. In comparison with the traditional unipolar CBPWM, the proposed hybrid CBPWM scheme can provide advantageous features, such as lower high-order harmonic distortion of the line current and better utilization of switching frequency. The separation coefficient value is optimized to achieve the maximum utilization of these advantages. The experimental results verify the feasibility and effectiveness of the proposed hybrid CBPWM scheme.

Comparative Proteomic Analysis of Yak Follicular Fluid during Estrus

Guo, Xian,Pei, Jie,Ding, Xuezhi,Chu, Min,Bao, Pengjia,Wu, Xiaoyun,Liang, Chunnian,Yan, Ping Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.9

The breeding of yaks is highly seasonal, there are many crucial proteins involved in the reproduction control program, especially in follicular development. In order to isolate differential proteins between mature and immature follicular fluid (FF) of yak, the FF from yak follicles with different sizes were sampled respectively, and two-dimensional gel electrophoresis (2-DE) of the proteins was carried out. After silver staining, the Image Master 2D platinum software was used for protein analysis and matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) was performed for differential protein identification. The expression level of transferrin and enolase superfamily member 1 (ENOSF1) was determined by Western blotting for verification analysis. The results showed that 2-DE obtained an electrophoresis map of proteins from mature and immature yak FF with high resolution and repeatability. A comparison of protein profiles identified 12 differently expressed proteins, out of which 10 of them were upregulated while 2 were downregulated. Western blotting showed that the expression of transferrin and ENOSF1 was enhanced with follicular development. Both the obtained protein profiles and the differently expressed proteins identified in this study provided experimental data related to follicular development during yak breeding seasons. This study also laid the foundation for understanding the microenvironment during oocyte development.

Effect of Surface Waviness on the Performances of an Aerostatic Thrust Bearing with Orifice-Type Restrictor

Hui Zhuang,Jianguo Ding,Peng Chen,Yu Chang,Xiaoyun Zeng,Hong Yang,Xingbao Liu,Wei Wei 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.10

In this paper, four waviness types are presented to investigate the effect of surface waviness on the static performance, dynamic performance and stability of an aerostatic thrust bearing with orifice-type restrictor. The influences of wave amplitude and rotational speed on the bearing performances are studied. The Reynolds equation is first solved through small perturbation method to obtain the static and dynamic characteristics. Subsequently, by adopting an iterative method based on the acquired dynamic coefficients, a numerical method is proposed to analyze the bearing stability. The calculated critical supply pressure is compared with that obtained by the traditional orbit method and it indicates that the proposed method has higher computational efficiency. The results show that the surface waviness has great influence on the bearing performances and the effect becomes increasingly pronounced with the growth of wave amplitude. The performances are more sensitive to the waviness arranged in bearing radial direction than circumferential direction. The enhancement of certain performance is always accompanied by the decline of another performance for the bearing with wave pattern on the surface, which leads to the fact that the bearing performances cannot be comprehensively improved in static characteristic, dynamic characteristic and stability. Besides, high rotational speed will cause pneumatic instability more readily. Finally, a stiff ness measuring experiment and a modal test are performed to verify the accuracy of computational analysis and results.

A Hybrid CBPWM Scheme for Single-Phase Three-Level Converters

Wang, Shunliang,Song, Wensheng,Feng, Xiaoyun,Ding, Rongjun The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

A novel hybrid carrier-based pulse width modulation (CBPWM) scheme that combines unipolar and dipolar modulations is proposed for single-phase three-level rectifiers, which are widely applied in railway traction drive systems. The proposed CBPWM method can satisfy the volt-second balancing principle in the complete modulation index region through overmodulation compensation. The modulation scheme features two modulation modes: unipolar and dipolar. The operation range limits of these modulation modes can be modified by changing the separation coefficient. In comparison with the traditional unipolar CBPWM, the proposed hybrid CBPWM scheme can provide advantageous features, such as lower high-order harmonic distortion of the line current and better utilization of switching frequency. The separation coefficient value is optimized to achieve the maximum utilization of these advantages. The experimental results verify the feasibility and effectiveness of the proposed hybrid CBPWM scheme.

Momordicine I alleviates isoproterenol-induced cardiomyocyte hypertrophy through suppression of PLA2G6 and DGK-ζ

Hongming Li,Yumei Qiu,Mengdie Xie,Changsheng Ouyang,Xiaoyun Ding,Hao Zhang,Wei Dong,Yinhua Xiong,Xilan Tang 대한약리학회 2023 The Korean Journal of Physiology & Pharmacology Vol.27 No.1

This study aimed to observe the protective effect of momordicine I, a triterpenoid compound extracted from momordica charantia L., on isoproterenol (ISO)-induced hypertrophy in rat H9c2 cardiomyocytes and investigate its potential mechanism. Treatment with 10 μM ISO induced cardiomyocyte hypertrophy as evidenced by increased cell surface area and protein content as well as pronounced upregulation of fetal genes including atrial natriuretic peptide, β-myosin heavy chain, and α-skeletal actin; however, those responses were markedly attenuated by treatment with 12.5 μg/ml momordicine I. Transcriptome experiment results showed that there were 381 and 447 differentially expressed genes expressed in comparisons of model/control and momordicine I intervention/model, respectively. GO enrichment analysis suggested that the anti-cardiomyocyte hypertrophic effect of momordicine I may be mainly associated with the regulation of metabolic processes. Based on our transcriptome experiment results as well as literature reports, we selected glycerophospholipid metabolizing enzymes group VI phospholipase A2 (PLA2G6) and diacylglycerol kinase ζ (DGK-ζ) as targets to further explore the potential mechanism through which momordicine I inhibited ISO-induced cardiomyocyte hypertrophy. Our results demonstrated that momordicine I inhibited ISO-induced upregulations of mRNA levels and protein expressions of PLA2G6 and DGK-ζ. Collectively, momordicine I alleviated ISO-induced cardiomyocyte hypertrophy, which may be related to its inhibition of the expression of glycerophospholipid metabolizing enzymes PLA2G6 and DGK-ζ.