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Table of Content

    18 February 2022, Volume 39 Issue 1 Previous Issue   
    Lysosomes and neurodegenerative diseases
    QU Lili, CANG Chunlei
    2022, 39 (1):  1.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 001
    Abstract ( 2528 )   PDF   Save
    Lysosomes are the main degradative organelles in eukaryotic cells, and their dysfunction is closely related to many diseases.The current knowledge on the connection between lysosomal dysfunction and neurodegenerative diseases were reviewed with the focus on lysosomal enzymes, pH regulation, lysosomal membrane proteins, and intracellular localization of lysosomes. It provided a new perspective for understanding the mechanism of neurodegenerative diseases, and also looke
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    The effect of lentivirus-mediated down-regulation of SHCBP1 on the proliferation of melanoma B16 cells#br#
    SUN Zhiyang, FENG Guang, LEI Jingjing, TANG Chengcheng, SUN Chenhao, WANG Ling, LU Hongzhao
    2022, 39 (1):  11.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 011
    Abstract ( 1760 )   PDF   Save
    To construct Shcbp1 lentiviral interference vector to explore the biological function of SHCBP1 in melanoma B16 cells, first,the shRNA-1 and shRNA-2 that target to interfere with the mouse Shcbp1 gene and the control sequence shRNA-NC were designed and connected to the lentiviral backbone vector, HEK293 cells were used to package the lentiviral particles to infect B16 cells, the interference efficiency was tested and CCK-8 and flow cytometry were used to detect cell viability and cell cycle. Western Blot was used to detect the expression of proliferation-related genes. The results showed that knockdown of Shcbp1 significantly inhibited the proliferation of B16 cells; flow cytometry results showed that knockdown of Shcbp1 blocked B16 cells in the G1 phase; the phosphorylation level of ERK1/2 decreased and the expression level of p21 increased. These results indicate that SHCBP1 may inhibit the transcription of P21 through the ERK1/2 signaling pathway and accelerate the progress of B16 cells from G1 to S phase
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    Prokaryotic expression of PelA-Expansin fusion protein
    WEI Lingling, YE Kaixia, LI Jiaxin, ZHAO Qingxin
    2022, 39 (1):  17.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 017
    Abstract ( 1316 )   PDF   Save
    Expansin can weaken the hydrogen bond between cell wall polysaccharides and enhance the efficiency of polysaccharide degradation by polysaccharide degrading enzyme. It has a wide range of application value in the field of food, bioenergy and biopharmaceutical.In the natural state, the expression of expansin protein in plants, fungi, bacteria and other organisms is less. At present, the research on the recombinant expression of expansin in Bacillus subtilis has been widely concerned. In this project, the expression project strain (newexpansin/ pelA-pET-28a(+) / BL21(DE3)) was constructed with the pectate lyase A (pelA gene from Aspergillus nidulans) as the fusion tag. At OD600 =0. 4, 0. 01 mmol/ L IPTG, 15 ℃ and 150 r/ min for 24 h, the fusion protein production was about 3. 0 mg/ mL. A one-step his-tag affinity purification process was established for the fusion protein and the concentration of imidazole in the sample loading, cleaning and elution buffer were 30, 60 and 500 mmol/ L, the purity of the target protein was about 95%, and the yield was about 75%. The degradation efficiencies of the fusion protein with cellulase, pectinase and xylanase were 300%,150% and 125%, respectively. This project laid the foundation for the application of expansin in the fields of food, energy, medicine and agriculture.
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    Functional verification of candidate lipid meTableolism gene Tmem176a based on transcriptome sequencing
    CUI Maosheng, DUAN Weiwang, LI Xiaoning, TANG Chen, LI Kai, ZHOU Yunxun, XIAO Junhua
    2022, 39 (1):  21.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 021
    Abstract ( 1363 )   PDF   Save

    The effects of overexpression and knockdown of Tmem176a on lipid metabolic pathways in Hepa1-6 cells were investigated.The constructed Tmem176a overexpression lentivirus vector and siRNA were transfected into Hepa1-6 cells. The overexpressed or knocked down with Tmem176a of Hepa1-6 cells were subjected to RNA-seq, bioinformatics analysis, and Real-Time PCR verification.Compared with the control group, Tmem176a was overexpressed 182 times (P<0. 05) and knocked down 0. 2 times (P<0. 05) in Hepa1-6 cells. There were 424 differentially expressed genes (DEGs) in OE-Tmem176a compared with that in OE-Vector, of which 233genes wereupregulated and 192 genes were downregulated. There were 405 DEGs of KD-Tmem176a compared with that of KD-Scramble,of which 157 genes were upregulated and 248 genes were downregulated. Some of the DEGs were enriched in metabolic pathwayssuch as fat digestion and absorption, cholesterol metabolism, glyceride metabolism, and fatty acid synthesis. The Real-Time PCR wasused to investigate some of the DEGs, and the change trend of the expression level of some investigated DEGs was consistent with that of RNAseq. RNAseq results indicated that Tmem176a affected gene response to lipid metabolism, and the changed expression level of Tmem176a promoted significant changes of gene expression level of lipid metabolism in mouse hepatoma Hepa1-6 cells.

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    Construction and characterization of fliC gene-inactivated mutant of Escherichia coli
    ZHAO Xingxing, CHENG Yumei, CHEN Xian, CUI Guzhen, QI Xiaolan , HONG Wei
    2022, 39 (1):  27.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 027
    Abstract ( 1618 )   PDF   Save

    To construct flagellin gene (fliC) inactivation mutant of Escherichia coli (ΔfliC) and explore its biological characteristics under stresses after alteration of biofilm formation. A fliC gene-inactivated mutant strain (ΔfliC420s) was constructed using the Thermotargetron targeted gene inactivation system. The changes of growth rate, motility, biofilm formation ability, autolysis rate, pH sensitivity and antibiotic tolerance of ΔfliC420s and wild-type strain were measured. Compared with wild-type strain, ΔfliC420s mutant had no effect on growth rate, its motility in semi-solid medium was reduced, the biofilm formation ability was significantly reduced, the autolysis rate of bacteria was accelerated, the pH sensitivity was enhanced, Interestingly, the tolerance of ΔfliC420s mutant to D-cycloserine, erythromycin, norfloxacin was reduced. The fliC gene of E. coli plays an important role in the formation of bacterial biofilm and resistance to external stresses.

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    Functional identification and bioinformation analysis of antimicrobial peptide from scorpion venom
    ZHU Chengang, JIA Ting
    2022, 39 (1):  33.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 033
    Abstract ( 1680 )   PDF   Save

    A scorpion gland cDNA library was constructed from the scorpion Liocheles australasiae which was collected from Hainan Province of China. And then an antimicrobial peptide gene, named La39, was screened from the cDNA library. Its mature peptide is composed of 18 amino acids, and its secondary structure is α-helix. Hydrophilic and hydrophobic amino acids are located on the opposite side of the molecule, forming a strong amphoteric topological structure. The results of MICs assay, and hemolytic experiments and growth inhibitory assay showed that the minimum inhibition concentration of La39 for Staphylococcus aureus was 50 μg/ mL, which, however, had no inhibitory activity on Escherichia coli, and had hemolytic activity.

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    Biocontrol effects of Bacillus velezensis on peanut stem rot caused by Sclerotium rolfsii
    PAN Mengshi, GUO Wenyang, ZHANG Zongyuan, YUE Dandan, QI Landa, WANG Xueyan, ZHANG Yingtao
    2022, 39 (1):  37.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 037
    Abstract ( 1927 )   PDF   Save

    As the potential biocontrol bacteria, Bacillus velezensis was studied for its biological control of peanut stem rot caused by Sclerotium rolfsii with coculture method, research of antagonistic mechanism and pot experiments. By coculture method on PDA, B.velezensis can inhibit the hyphal growth of S. rolfsii significantly, with an inhibition rate of 81. 93%, destroy the structure of the pathogenic mycelium and prevent the formation of sclerotia. In order to understand antagonistic mechanism of B. velezensis, it was found that B. velezensis can produce protease, cellulase, amylase and siderophore, which aseptic fermentation filtrate also has an antagonistic effect. Under pot experiments the treatments with bacteria liquid can inhibit the occurrence of peanut stem rot caused by S. rolfsii, reduce the peanut disease index, and have a certain promotion effect on the growth of peanuts. Peanuts which colonizated with S. rolfsii for 2 days and then sprayed by the bacteria liquid exhibited greater than other treatments with 66. 15% biocontrol efficacy against S.rolfsii. B. velezensis can be used for the prevention and treatment of peanut stem rot caused by S. rolfsii, and has a good prospect for biocontrol.

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    Toxins isolation and identification from two mycoparasites of plant rust and its activities
    LI Jing, XIE Jin, KONG Lei, ZHANG Dengyun, SUI Guoqiang, CHEN Yuhui
    2022, 39 (1):  42.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 042
    Abstract ( 1043 )   PDF   Save

    The control of plant rust is very difficult and its biological control focuses on the study of mycoparasites. Previous studies showed that P. kenyana PG52 and T. koningii 8662 had strong parasitic effects on aeciospores of Aecidium wenshanense and Cronartium ribicola, however, the mechanism of mycoparasitism is unclear. Two kinds of toxins, identified as 3-nitro propionic acid and citric acid, were isolated from two mycoparasites using bioassay-guided method for the first time and they had a lethal effect on aeciospores.The cell membrane permeability of aeciospores was changed by two kinds of toxins and aeciospores were significantly smaller comparedwith the control. Aeciospores were confirmed dead by Trypan blue staining. After treatment by 10 μg/ mL 3-nitro propionic acid and 100 μg/ mL citric acid for 1 h, the fatality rate of aeciospores reached 50% by Trypan blue staining. When the mass concentration of citric acid was more than 500 μg/ mL, fatality rate reached 90%. Also 500 μg/ mL citric acid had a lethal effect on aeciospores of Aecidium pourthiaea, teliospores of Sterostratum corticioides and urediospores of Uromyces trifolii. The above results laid a foundation for mycoparasitism clarification and indicated a good biopesticide application prospect.

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    Isolation and analysis of degradation ability of PAHs-degrading bacteria tolerant to diverse physical settings
    ZHEN Jing, LI Lei, WANG Jiwen, YANG Wenling, DU Zhimin, LI Liangliang, GONG Tao
    2022, 39 (1):  46.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 046
    Abstract ( 596 )   PDF   Save
    In order to obtain PAHs-degrading bacteria tolerant to diverse physical settings, a high efficient polycyclic aromatic hydrocarbons-degrading bacterial strain was isolated by heavy metal tolerance capacity and lack of nitrogen source culture method from a soil collected from Nanyang petroleum contaminated soil. The strain was identified by morphological characteristics and molecular biological methods, and its tolerance to heavy metals (Cr6+ and Cu2+ ), lack of nitrogen source and acid-base tolerance was studied to further explore the degradation effect of phenanthrene and pyrene under these adverse environmental conditions. The isolated strain was Rhizobium pusense, named F3-1. The result showed that the higher tolerance mass concentration of metals (Cr6+ and Cu2+ ) of the strain F3-1 was 20 mg/ L. The strain F3-1 could grow normally under the condition of absence of nitrogen source, pH 5. 0 and pH 7. 4. The strain F3-1 could degrade single phenanthrene or single pyrene under extreme conditions. After 5 days, the strain F3-1 could degrade 35. 54% of phenanthrene(50 mg/ L) at pH 7. 4, and the degradation rate of pyrene (50 mg/ L) was up to 35. 54% at pH 5. 0.
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    Araneus ventricosus recombinant chimeric spidroin: a biomaterial with high molecular weight
    JIA Qiupin, MENG Qing
    2022, 39 (1):  51.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 051
    Abstract ( 438 )   PDF   Save
    A tripartite chimeric recombinant spidroins iN7RC was designed based on two spidroin genes from Araneus ventricosus, successfully expressed in E. coli cells, and obtained a highly pure 162. 5 ku recombinant spidroin through purification at a yield of 34 mg/ L.The circular dichroism (CD) spectra of iN7RC spidroin solution under different pHs indicated that the content of the secondary structure α-helix was distinctly decreased along with the declining pH value. Recombinant spider silk fibers with superior strength and extensibility were acquired by hand-drawing, which paved the foundation for the extensive application of biomaterials.
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    Preparation and properties of keratin porous materials with biomimetic mineralization
    JI Ji, CHEN Guang, LI Lili, YUAN Jiugang, YUAN Chao, WANG Ping, XU Bo
    2022, 39 (1):  57.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 057
    Abstract ( 341 )   PDF   Save

    To improve the poor mechanical properties of pure keratin porous materials, a modified keratin of polyethylene glycol dimethacrylate (PEGDMA) was prepared by thiolene click reaction. The modified keratin was blended with sodium alginate (SA). Finally,biomimetic mineralized keratin porous materials were prepared by alternating mineralization method. FTIR results showed that PEGDMA was successfully grafted onto keratin. The elasticity of porous materials was obviously improved after modification. The results of SEM, FTIR and XRD showed that HAP was successfully deposited on the surface of porous materials. The surface of porous materials became rough. After mineralization, the properties of keratin porous materials were comprehensively improved, the yield point stress was to 3. 1 MPa, the biocompatibility increased to 117. 86%, Cu2+ adsorption was up to 159. 0 mg/ g. This was of great significance for expanding the application of keratin porous materials.


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    Genome-wide identification and expression analysis of CIPK gene family in Glycyrrhiza uralensis
    XIAN Yajie, WANG Fei, XIE Shuangquan, CHEN Xifeng, SHEN Haitao, LI Hongbin
    2022, 39 (1):  62.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 062
    Abstract ( 507 )   PDF   Save

    In order to explore the characteristics of CIPK family members and predict their function, the CIPK family genes of Glycyrrhiza uralensis were identified by bioinformatics, and their phylogeny, gene structure, conserved motif and evolutionary relationship were analyzed. The results showed that 22 GuCIPK genes were identified from Glycyrrhiza uralensis, and chromosomal location analysis showed that they were distributed on 19 different scaffolds. Amino acid sequence alignment indicated that most of the GuCIPKs contained a Ser/ Thr domain, a NAF domain and a PPI domain. Phylogenetic tree analysis displayed that the 22 GuCIPKs could be classified into 5 subfamilies, and there existed multiple parallel homologous gene pairs between GuCIPKs and CIPKs of Arabidopsis thaliana and Glycine max. G. uralensis GuCIPK promoter regions included some cis-elements involved in response to abiotic stress and hormone,suggesting their potential functions under regulation of different signals. Tissue-specific expression pattern analysis showed that the GuCIPKs could be classified into four groups Ⅰ-Ⅳ, and the six members of group Ⅱ had high accumulations in roots, stems and leaves, while the other GuCIPK members of groups Ⅰ, Ⅲ and Ⅳ three groups appeared relative low abundance in the tissues of root, stem and leaf. Quantitative real time PCR (qRT-PCR) analysis demonstrated that GuCIPK genes were induced significantly by different abiotic stresses of salt, oxidation, drought, high temperature and low temperature. These results provide effective reference to investigate the GuCIPK function and elucidate the possible regulatory mechanism.


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    Effects of different habitats on photosynthetic characteristics and the optimal model of light response curves of Buddleja officinalis Maxim.
    CHEN Lanying, XIAO Juan
    2022, 39 (1):  69.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 069
    Abstract ( 307 )   PDF   Save

    To reveal the photosynthetic physiological characteristics and select the best fitting model to analyze the photosynthetic-light response curve of Buddleja officinalis Maxim. in different habitats, the plant high, basal diameter, leaf area, inflorescence ength,flavonoids,photosynthetic characteristics (using a portable photosynthesis system LI-6400 to measure photosynthetic light response curves and diurnal variations of photosynthesis) and chlorophyll contents in canopy gap, forest edge and forest understory were measured and compared. The results showed that the plant high, basal diameter, leaf area, inflorescence length and flavonoids were the highest in the canopy gap (P<0. 05). The chlorophyll-a, chlorophyll-b, and total chlorophyll contents were the highest in the canopy gap, and the lowest in the understory (P<0. 05). The diurnal variation of the net photosynthesis rates in the leaves of B. officinalis in the canopy gap and understory showed one-peak curve, whereas at the forest edge it showed a double-peak curve with remarkable midday depression. The modified rectangular hyperbola model was the best fitting model for the light response curve of B. officinalis, and the light saturation intensity in three different habitats were 1 424. 70, 1 725. 76, and 1 608. 85 μmol/ (m2·s), respectively; the maximum net photosynthetic rates were 14. 07, 17. 54, and 16. 30 μmol/ (m2·s), respectively; and the light compensation points were 26. 59, 19.08 and 20. 89 μmol/ (m2·s), respectively; which were consistent with the characteristics of semi-negative to semi-positive plants. The lower light compensation point and higher light saturation point occurred in the canopy gap, indicating that B. officinalis in canopy gaphad wider ecological amplitude to light than that other habitats. B. officinalis had the characteristics of combining shade plant and heliophyte,and the canopy gap habitat might be helpful to accumulation of organic materials and more suitable for the growth. Planting in the understory habitat needs to improve canopy light penetration in time, then at the forest edge, the appropriate shading is required.

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    Effect of cornus iridoid glycosides on mouse vascular endothelial cells
    ZHANG Yang, YANG Jing, GAO Jianping, CHEN Yi, KONG Yingjun, XIA Leilei, ZHANG Guifeng, LI Yongchao
    2022, 39 (1):  75.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 075
    Abstract ( 320 )   PDF   Save
    The cornus iridoid glycosides ( CIG ) were extracted and detected, and the influence of CIG to vascular endothelial cell was studied. The cornus was extracted by ultrasonic and treated with D101 macroporous resin to remove the impurities such as pigment and sugar, and the extraction was compared with four standards using HPLC-MS. The effects of CIG on mouse vascular endothelial cell proliferation,cell morphology and cell apoptosis were studied. The results showed that, 0. 5-50 μg/ mL CIG could promote the vascular endothelial cell proliferation and inhibit cell atrophy and apoptosis caused by high glucose.Cell damage and apoptosis were important for thrombosis. Cornus as the medicine and food could reduce the risk of thrombosis.
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    The species and faunal analysis of Pissodes Germar in China
    ZHANG Xinmin, HAN Xiu, LIU Xia, XIONG Zhongping
    2022, 39 (1):  80.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 080
    Abstract ( 488 )   PDF   Save

    Forty-six species of Pissodes Germar (Coleoptera, Curculionidae) have been currently recorded in the world. 29 species are distributed in America, 18 in Europe and Asia, and 8 in China. Many species of Pissodes are important pests of conifers, which mainly damage coniferous trees such as Pinus Linn, Picea Dietr and Abies Mill. Pissodes is one of the serious forest diseases and insect pests in Southwest China in recent years. The harm of these pests is very serious since their hosts are widely distributed in China, so it is urgent to be vigilant to prevent them from being introduced into other regions of China through trade channels or human factors. The research history, host and distribution of Pissodes were systematically summarized. A binomial key table of 8 species of Pissodes in China was compiled, the distribution characteristics of Pissodes species from world zoogeographical regions and Chinese zoogeographical zones were analyzed, the existing problems in the taxonomy of Pissodes were pointed out, and the prospect was put forward.

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    Effects of light intensity on behavior, learning memory and oxidative stress of Tupaia belangeri
    PENG Hongbi, JIA Ting, WANG Zhengkun, ZHU Wanlong
    2022, 39 (1):  84.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 084
    Abstract ( 427 )   PDF   Save

    To investigate the effects of different light intensities on the behavior changes, learning memory ability and oxidative stress inTupaia belangeri, body mass, food intake, behavior and correct response rate in Y-maze, concentrations of malondialdehyde (MDA),superoxide dismutase (SOD), acetylcholinesterase (AChE) and nitric oxide synthase (NOS), as well as activities of SOD, AChE and NOS were measured in T. belangeri, which were continuously exposed to 628, 1 256 and 2 512lx. The results showed that body mass had significant differences among three groups, changes of food intake were similar to body mass in T. belangeri. Higher light intensity reduced feeding behavior and increased resting behavior significantly. On day 28, there was a significant difference in recognition accuracy among different light intensity groups. Different light intensity had significant effects on the concentrations of MDA, concentration and activity of SOD, and the activities of NOS and AChE. All of the results indicated that higher light intensity reduced body mass and feeding behavior, increased rest behavior, and induced cognitive impairment and caused different degrees of oxidative damage in T. belangeri.


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    Research advances in biological effects of static magnetic field combined with drugs on tumor cells
    ZHANG Ning, SONG Chao, ZHANG Xiangfei, LI Zhiyuan
    2022, 39 (1):  89.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 05. 01. 089
    Abstract ( 331 )   PDF   Save
    Static magnetic fields (SMFs) have an inhibitory effect on tumors, and many advances have been made in combination with drugs to improve the efficacy of tumors. Herein after a detailed review of the effects of static magnetic fields combined with commonly used drugs such as pingyangmycin, cisplatin, doxorubicin, 5-fluorouracil, paclitaxel, vitamin D, capsaicin, etc on tumor cells, it was found that static magnetic fields of specific intensity combined with specific drugs could significantly reduce the concentration and side effects of the drug, but it had an antagonistic effect or no obvious effect on some tumors. Therefore, the biological effects of SMF-drug combination depend on drug type, magnetic field intensity, and cell type. The research advances were reviewed on effects of magnetic field combined with different drugs, in order to provide a reference for clinically static magnetic field and drug combination.
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    Interaction between hydrogen sulfide and abscisic acid in the response of plants to environmental stress
    WANG Jiaqi, XIANG Ruhua, LI Zhongguang
    2022, 39 (1):  94.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 094
    Abstract ( 424 )   PDF   Save
    Hydrogen sulfide (H2S) and abscisic acid (ABA) are important signaling molecules and stress hormones in plants, which regulate plant growth and development as well as response to environmental stress in an alone or interactive manner. The metabolic mechanisms of H2S and ABA in plants were analyzed. The interaction between H2S and ABA in the response of plants to drought, high temperature, cold, and osmotic stress, as well as in the regulation of stomatal movement, seed germination, and root growth was summarized.The mechanism of the interaction between H2S and ABA was stated, which laid the foundation for researching the H2S-ABA interaction in plant growth and development as well as response to environmental stress. In addition, the molecular mechanism of H2SABA interaction, crosstalk of H2S with other signaling, new members of signaling network, and signalome were prospected.
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    Research progress of mammalian testicular clock
    XIAO Yaoyao, WANG Yiqun, ZHANG Linlin , PAN Tao, JIN Yaping, CHEN Huatao
    2022, 39 (1):  99.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 099
    Abstract ( 311 )   PDF   Save

    Based on the data reported in literature and the previous experience, the molecular mechanism of mammalian circadian clock system and the research progress of testicular circadian clock within the past two decades are summarized, and the evidence of the presenceof the testicular circadian clock in mammals is put forward. Afterwards, a series of important reproductive physiological processes regulated by mammalian testicular circadian clock are elaborated, such as testosterone synthesis and spermatogenesis. Moreover, other important factors affecting mammalian testicular clock, such as aging, stress, and harmful chemicals, are also briefly listed. In addition,

    the current studies on the molecular mechanism of testicular circadian clock maintenance, its regulation of other reproductive accessory

    cells physiological functions and spermatogenesis within specific periods, and the construction of tissue-specific and conditional knockoutmouse models are analyzed. This article advances our understanding on how to find the target sites to increase testosterone levels and sperm motility, and effectively improve the reproductive potential of male breeding animals from the perspective of testicular circadian clock.

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    Process optimization of preparation of antioxidant chitooligosaccharides by papain
    HUANG Xiaoyue, BI Siyuan, OU Jiahao, SUN Lijun, CHEN Siqi, FANG Zhijia, DENG Qi, DENG Yijia, WANG Yaling
    2022, 39 (1):  104.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 104
    Abstract ( 310 )   PDF   Save
    In order to clarify the papain process for the preparation of chitooligosaccharides with high antioxidant activity, chitosan was used as raw material, the DPPH radical scavenging rate and total reducing power of the hydrolysates were used as detection indexes.The single factor experiment was used to explore the effects of enzyme substrate ratio, temperature, pH value and time on the antioxidant activity of the hydrolysates. The optimal conditions were determined as enzyme substrate ratio of 20%, temperature of 50. 00 ℃ and pH value of 4. 80. On the basis of single factor experiment, box Behnken response surface method was used to design and optimize the hydrolysis temperature, time and pH value. The optimal hydrolysis conditions were obtained as follows: temperature of 47. 74 ℃,pH of 4. 81 and time of 1 h. Under these conditions, the DPPH radical scavenging rate of chitosan hydrolysate was 65. 10% and the total reducing power was 0. 323. The experiment was repeated under the conditions of enzymolysis temperature of 48. 00 ℃, enzymolysis pH of 4. 80 and enzymolysis time of 1 h, the result showed that the DPPH radical scavenging rate of chitosan hydrolysates was 65. 43%±0. 71%, IC50 was 1. 86 mg / mL±0. 10 mg / mL, and the total reducing power was 0. 328 ± 0. 01, which was equivalent to the reducingpower of 39. 44 μg/ mL±2. 94 μg/ mL ascorbic acid. The average molecular weight of this chitooligosaccharide was 1 603 u and the yield of this chitooligosaccharide was 45. 07% ± 3. 52%. The result can provide a theoretical reference for the development of chitooligosaccharides with antioxidant activity.
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    Preparation of high-purity plasmin-α2-plasmin inhibitor and thrombin-antithrombin complex
    ZHOU Shuaihui, WANG Weijie, YU Zheng, REN He, LI Shuaipeng, YANG Yangkun, BAI Zhonghu
    2022, 39 (1):  110.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 110
    Abstract ( 548 )   PDF   Save

    In order to obtain plasmin-α2-plasmin inhibitor complex (PIC) and thrombin-antithrombin (TAT) monoclonal antibodies and establish a detection method of the corresponding complex, it is necessary to prepare high-purity PIC and TAT complexes. With lipemia plasma as the research material, the plasma pretreatment was first performed. Plasma was activated by urokinase and passed through Lysine-sepharose affinity column to finally obtain high-purity PIC. After the treated plasma is adsorbed by barium chloride and precipitated with saturated ammonium sulfate, antithrombin and prothrombin are obtained. Ecarin snake venom is used to activate prothrombin to obtain thrombin. The thrombin and antithrombin were passed through Heparin-sepharose, respectively. Affinity column was used to improve its purity, and it was mixed and reacted in vitro to obtain a TAT mixture, and then through a Heparin-sepharose affinity column to remove unreacted thrombin and antithrombin, and finally obtain high-purity TAT. The product was identified and quantified by SDS-PAGE, ultraviolet spectrophotometry and HISCL automatic analyzer. The results showed that the best activation condition for PIC was 2 mg urokinase/100 mL plasma, activated at 37 ℃ for 30 min; 2. 5 mg PIC was obtained, with a purity of more than 90% identified by SDS-PAGE. The activation condition of prothrombin was 0. 5 mL snake venom/100 mL plasma, activated at

    37 ℃ for 20 min, and finally 2. 1 mg thrombin and 6. 2 mg antithrombin were obtained from 100 mL plasma. The optimal reaction mass ratio of thrombin and antithrombin in vitro was 0. 7 ∶ 1, and the purity of TAT was more than 80% identified by SDS-PAGE.


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    Exploration and application of PBL combined flipped classroom teaching model in medical molecular biology experiment teaching
    YAN Xianchun, CAO Xiuli, BU Xin, HAN Hua, LIANG Liang
    2022, 39 (1):  115.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 115
    Abstract ( 394 )   PDF   Save

    The question “whether Dll4 extracellular domain can inhibit endothelial cells angiogenesis” is probed to discuss the application of PBL incorporated with flipped classroom teaching model in medical molecular biology experimental teaching. Different from the traditional teaching which separates theory and experiment of molecular biology apart, this teaching model organically integrates a variety of common molecular biology experimental techniques such as DNA extraction, PCR, nucleic acid electrophoresis, and gel recovery by engaging students to solve a scientific problem. On one hand, it strengthens the practical application of the techniques. On the other hand, combination of PBL with flipped classroom teaching model can further enhance students’ enthusiasm and subjective initiative in knowledge exploration, and ultimately achieve practical improvement of students’ scientific research ability to discover, analyze and solve problems.

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    Research progress of biology education based on immersive media technology
    DU Hui, BAI Jiangzhu, WANG Dong, ZHOU Rongting
    2022, 39 (1):  118.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 118
    Abstract ( 349 )   PDF   Save
    In order to investigate the theoretical researches and development of immersive media technology in biology teaching, the bibliometric methods like co-word and co-occurrence analysis and knowledgegraph were used, the relevant research literatures in the domestic and foreign authoritative databases were collected, the increasing trend of the publications was revealed, and the leading scientific research institutions and teams were analyzed. The research hotspots in this field were explored by co-word analysis, and it is found that the hotspots of domestic researches included teaching reform, virtual experiment and application scenarios, while the hotspots of foreign researches included education and environment, molecular visualization and cognitive and psychology related studies,and provided reference and guidance for the researchers and practitioners of biology teaching.
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    T vector for protein expression in molecular biology comprehensive experiments design
    DAI Gu, TAO Nianjiao, ZHU Dan, SHI Li
    2022, 39 (1):  123.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 123
    Abstract ( 365 )   PDF   Save
    In the traditional molecular biology experiment, α-complementation method for screening recombinants and protein expression in prokaryotic cells were two independent experimental technologies. In order to make up for the lack of continuity of these two experiments,a comprehensive experiment of gene cloning and protein expression integrative in one vector was designed to strengthen the students􀆶 understanding of the reading frame. The comprehensive experimental design in molecular biology experiments could expand the span and depth of experimental teaching, and laid the foundation for further promoting students􀆶 knowledge, ability and professionalism.
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    Using methodology as the keystone to foster bioinformatics literacy
    LI Bo, HE Hao, ZHANG Xiaoxi, LI Yinghong, YANG Dan
    2022, 39 (1):  127.  doi: 10. 3969/ j. issn. 2095-1736. 2022. 01. 127
    Abstract ( 364 )   PDF   Save
    Taking methodology as the entry point and combining with the rapid development of modern life science and scientific research practice, several important bioinformatics strategies or approaches were summarized and refined, which included the ideas of experimental- control comparison, distance and similarity, feature selection and feature extraction, clustering analysis, classification and prediction, data integration and re-analysis, databases and web-based tools, and so on. These bioinformatics strategies are designed to help students learn and understand computational thinking and methods that are different from traditional experimental biology in a short period of time, and to deepen their understanding of interdisciplinary research approaches in biology. In a word, the introduction of bioinformatics research strategies or approaches in biology-related courses can strengthen the mathematical thinking and the ability to apply cross-disciplinary biology-related knowledge of students, improving the quality of undergraduate training.
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