18 April 2022, Volume 39 Issue 2 Previous Issue   
Mitochondria and neurodegenerative disease
SHI Yunyu, ZHANG Liang
2022, 39 (2):  1.  doi: 10.3969/j.issn. 2095-1736.2022.02.001
Abstract ( 114 )   PDF  
In order to understand mechanism of neurodegenerative diseases and to achieve the purpose of diagnosis and therapy, this paper discusses mitochondrial genome and mitochondrial gene transcription, translational and epigenetic regulations; mitochondrial dynamics, fusion, fission, and mitophagy; the transportation of mitochondria at synapses; mitochondrial dysfunction-activating the innate immunity system-causing chronic inflammation-leading to neurodegenerative diseases. These four aspects are elaborated in order to have a deeper understanding of the physiological functions of mitochondria and pathological of neurodegenerative diseases, and lay a background for the diagnosis and therapy of neurodegenerative diseases.
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Intrinsic oxidase-like nanozyme of Pt@ MXene composites (PMCs) for killing bacteria, disinfecting wound
LIU Chao, SHAO Changsheng, ZHENG Xinxin, HUANG Qing
2022, 39 (2):  11.  doi: 10.3969/j.issn. 2095-1736.2022.02.011
Abstract ( 106 )   PDF  
To develop antibacterial materials with high antibacterial activity and biocompatibility of high demand for public health and safety, in this work, we have successfully synthesized Pt@ MXene composites (PMCs),which possess excellent oxidase-like activity and show the activity of inhibition of both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) with high efficiency. The antibacterial mechanism revealed that PMCs had both excellent oxidation enzyme activity with corresponding electron transfer ability and large specific surface area, which led to the effective inhibition of the growth of bacteria. Moreover, the designed system showed excellent wound healing ability in vivo with good biocompatibility. Therefore, this work has not only proposed an effective way in designing and exploring nanozyme-like antibacterial materials, but also demonstrated the promising potential of application of PMCs in disinfection and wound-healing therapy.
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Phylogenetic and molecular evolution analyses of DXS gene in plants
MAO Jipeng, HUANG Linwang, HAO Jing, LIU Tianyi, HUANG Shaowei
2022, 39 (2):  23.  doi: 10.3969/j.issn.2095-1736.2022.02.023
Abstract ( 78 )   PDF  
In order to understand the phylogenetic, codon bias and molecular evolution characteristics of DXS gene, the DXS gene sequences from 44 representative species were selected for analysis. The results showed that the DXS gene family was highly conserved and the mean genetic distance between sequences was 0.243. The differentiation time of DXS gene preceded the species differentiation, and the phylogenetic tree of DXS gene and species was the same topological structure. The gymnosperm, monocotyledonts and the same family plants of dicotyledonts were clustered together, respectively. The codon bias of DXS gene was low, and the average effective number of codon, GC3 and G+C contents were 47.25, 0.49 and 0.51, respectively. DXS gene was mainly subjected to purification selection in the evolutionary process, the DXS gene of Glycine soja with the maximum dN/dS of 0.981, and the DXS gene of Panicum hallii with the minimum dN/dS of 0.001, the average dN/dS was 0.094. There were no positive selection sites with BEB greater than 0.95 detected in all models. There was no significant correlation between the effective number of codon, GC3, G+C contents and the dN/dS of DXS gene. This study provided a theoretical basis for further research on the function of DXS gene and its regulatory mechanism in the MEP pathway.
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Leaf structure and chlorophyll fluorescence of Lantana camara
LI Yanyan, ZHANG Ziwei, HUANG Wei, NIE Chuanpeng
2022, 39 (2):  29.  doi: 10.3969/j.issn. 2095-1736.2022.02.029
Abstract ( 50 )   PDF  
Lantana camara taken as test material, its photosynthetic physiological characteristics were revealed by measuring and analyzing the leaf structure, photosynthetic pigment content and chlorophyll fluorescence parameters, so as to provide reference for ornamental cultivation of Lantana camara. The results showed that the Lantana camara leaves had thick cuticle and photosynthesized tissue, the density of palisade tissue was 41.9, the ratio of palisade tissue to spongy tissue was 0.99, and the content of chlorophyll was 4.12 mg/g. The photochemical quenching coefficient (QP) and non photochemical quenching coefficient (NPQ) decreased gradually from 8:00 to 10:00, indicating that the utilization rate of light energy was gradually increased. When the light intensity increased from 190 to 1150μmol/m2·s, the relative electron transfer efficiency (ETR) continued to increase, the maximal PSII photochemical efficiency (Fv/Fm) decreased significantly, and the actual PSII photochemical efficiency Y(II) decreased slowly after a small increase, and maintained a high level when the PAR was 285-420 μmol/m2·s. The non photochemical quenching yield Y(NPQ) increased with the increase of PAR except that decreased slightly at 625 μmol/m2·s. Correlation analysis showed that there was a correlation between the anatomical structure and fluorescence parameters of Lantana camara leaves, but none of them reached a significant level; the effects of chlorophyll content on six fluorescence parameters were as follows: ETR>Y(NPQ)>Y(Ⅱ)>NPQ>qP>Fv/Fm, and chlorophyll content was positively correlated with ETR. Therefore, Lantana camara had strong photosynthetic performance and high tolerance to light intensity, which was suitable for the high temperature and strong sunshine environment.
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Preliminary explorations of potential active components and mechanisms of “natural plant antimicrobial solution” (PAMs) against SARS-CoV-2
YANG Lei, AO Zhiguang, XIANG Kun, HE Jiameng, CHANG Miao, LI Dong, MAO Canquan
2022, 39 (2):  34.  doi: 10.3969/j.issn.2095-1736.2022.02.034
Abstract ( 56 )   PDF  
In order to explore the possible active components and mechanisms of “natural plant antimicrobial solutions” (PAMs) produced by Yunnan Pu’er Danzhou Pharmaceutical Co., Ltd. for SARS-CoV-2, the chemical components coming from the medicinal plants of PAMs and their drug targets were searched using TCMSP, BATMAN and YaTCM databases. The disease targets for coronavirus were obtained through the GeneCards database. Cytoscape mapping was applied to construct the “medicinal plant-component-target-disease” network and potential targets in PPI network. GO and KEGG enrichment analysis were utilized to predict the possible mechanism of PAMs. The main active components of PAMs were molecularly docked with the key proteins of SARS-CoV-2. Finally, M13 bacteriophages were used as the virus model for determination of the inhibitory effect of PAMs on virus. A total of 166 kinds of active components of PAMs, 1007 kinds of drug targets, and 73 kinds of drug-coronavirus interaction targets were obtained. PTGS2, PTGS1, PPARG, DPP4, CALM1, CASP3, RELA and BAX were found to have target degrees greater than 10 in the medicinal plant-component-target-disease network. A total of 2109 entries were obtained by GO enrichment analysis, which were mainly involved in the regulations of cytokines, protein phosphorylation, and immunity. KEGG was enriched to 144 signaling pathways, and the top five were human cytomegalovirus infection, TNF, Kaposi’s sarcoma-associated herpesvirus infection, influenza A, and hepatitis B. The results of molecular docking showed that luteolin, quercetin and baicalein had strong binding ability to 3CL hydrolase (Mpro) and spike glycoprotein of SARS-CoV-2 while baicalein, myricetin, and quercetin had strong binding ability to angiotensin converting enzyme (ACE2). At concentration of 20%, PAMs could inhibit the growth of M13 to over 99%. In conclusion, PAMs might act on SARS-CoV-2 through multiple components, targets and pathways. The active components of quercetin, baicalein, and luteolin of PAMs mainly came from safflower and comfrey had lower binding free energy for Mpro, ACE2 and spike glycoprotein, indicating its possible adjuvant and therapeutic effects on COVID-19.
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The study on EPO gene nucleotides polymorphism in Tashkurgan sheep
WANG Shifeng, YIN Fangliu, GAO Hongjuan, ZHAN Jianli, ZHANG Xiuying, TUERXUN·Abudureheman
2022, 39 (2):  40.  doi: 10.3969/j.issn. 2095-1736.2022.02.040
Abstract ( 47 )   PDF  
To analyze the relationship between EPO gene polymorphism and altitude hypoxia adaptation in Tashkurgan sheep in Pamir Plateau of Xinjiang, molecular genetic characteristics, SNP, haplotype composition and population genetic characteristics of part of EPO gene (1 382 bp) were analyzed by PCR, direct sequencing and bioinformatics methods. Seven haplotypes and five SNP sites were obtained by analyzing EPO nucleotide sequences of 39 Tashkurgan sheep, among which Hap_3 was the dominant haplotype (64%), SNP/C1991A may be related to the molecular mechanism of hypoxia adaptation in sheep. The results showed that EPO gene was very conservative, mutations occurred only in the noncoding region and intron region. It was speculated that EPO might be involved in hypoxia adaptation at the level of gene expression or expression regulation rather than the sequence itself. The results indicated that EPO gene could be used as a candidate gene for plateau hypoxia adaptive evolution research and molecular assisted breeding of sheep. It will provide basic data for genetic improvement in Tashkurgan sheep.
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Transcriptome analysis of major endocrine signaling pathways of BAT in Tupaia belangeri during cold acclimation
WANG Huijuan, JIA Ting, ZHU Wanlong, WANG Zhengkun
2022, 39 (2):  45.  doi: 10.3969/j.issn. 2095-1736.2022.02.045
Abstract ( 42 )   PDF  
In order to investigate the regulation mechanism of insulin and thyroid hormone signaling pathways in brown adipose tissue (BAT) in Tupaia belangeri under cold acclimation, in the present study, transcriptome sequencing of BAT in T. belangeri between control and cold acclimation group were carried out by Illumina novaseq 6000 platform, respectively. Then the signal pathways and candidate genes related to insulin and thyroid hormone were screened out by bioinformatics analysis. The results showed that there were significant differences in the expression of 2 879 genes in cold acclimation group compared with that of control group, 1 181 were up-regulated and 1 698 were down-regulated in cold acclimation group. The results of GO analysis showed that there were 24, 28 and 55 terms were significantly enriched in cellular components, molecular functions and biological processes, respectively, and differentially expressed genes were mainly enriched in biological processes. KEGG analysis showed that the differentially expressed genes were significantly enriched in 20 pathways, and candidate genes related to insulin and thyroid hormone signaling pathways were screened out, including PDPK1, AKT2, ACACA, SLC2A4, and THRB, etc. All of the above results indicated that the T. belangeri could adapt to the cold environment by regulating genes expression in insulin and thyroid hormone pathways in BAT.
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Urine metabolomics of giant panda (Ailuropoda melanoleuca)
XIE Tingxia, LI Caiwu, DENG Wenwen, JIN Lei, HE Yongguo, WU Daifu, ZHANG Hemin, HUANG Yan, ZOU Likou
2022, 39 (2):  52.  doi: 10.3969/j.issn. 2095-1736.2022.02.052
Abstract ( 38 )   PDF  
In order to explore the difference of metabolites in giant panda urine, 20 cases of giant panda urine metabolites were detected by liquid chromatography-mass spectrometry (UPLC-Q-TOF/MS), and differences in urine metabolites were analyzed according to gender and age. As results, 12 metabolites with significant difference (P<0.05)were identified between the gender group, and the relative expression of 11 metabolites except for apigenin was higher in male urine. A total of 25 significantly different metabolites (P<0.05) were identified between the sub-adult group and the adult group. Only the relative expression levels of riboflavin and arginine were higher in the urine of the sub-adult giant panda. Ten significantly different metabolites (P<0.05)were identified between the sub-adult group and the geratic group, and three significantly different metabolites were identified between the adult group and the geratic group. The relative expression of these substances was higher in the urine of elderly individuals. These metabolites with significant differences were mainly concentrated in the amino acid metabolism pathway, the biosynthesis pathway of secondary metabolites and the biosynthesis pathway of flavones, flavonols and flavonoids. The urine metabolites of giant pandas of different genders and ages were analyzed in this study.The differential metabolites obtained by screening can provide a theoretical basis for the study of chemical communication mechanism and physiological function of giant pandas.
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Effects of high temperature and high pressure on the toxicity induced by modified T-2 toxins (mT-2s) in mice
SONG Yinghui, QIU Mei, SUN Lijun, WANG Yaling, ZHOU Daozhi, YE Lin, DENG Qi, FANG Zhijia
2022, 39 (2):  58.  doi: 10.3969/j.issn. 2095-1736.2022.02.058
Abstract ( 34 )   PDF  
High temperature and high pressure technology is a technology that eliminates harmful microorganisms in food to achieve commercial sterile conditions without adding harmful substances such as preservatives. In order to investigate the toxic effect of the modified T-2 toxin (mT-2s) in mice induced by high temperature and high pressure treatment, through the mouse exposure experiment, mT-2s was treated under high temperature and high pressure, forty mice were randomly divided into mT-2s group (untreated), mT-2s group treated with high temperature and high pressure, negative control and positive control group, which were administered by oral to mice for 7 days. The immune organ index, bone marrow micronucleus rate, sperm deformity rate and serum biochemical indexes of mice were detected to analyze its change characteristics.The results showed that compared with that of the untreated group, the immune organ index, bone marrow micronucleus rate, sperm malformation rate and serum biochemical indexes of the mice treated with high temperature and high pressure were significantly different (P<0.05); compared with that of the positive control group, the immune organ index, bone marrow micronucleus rate, sperm malformation rate and serum biochemical indexes of mice treated with high temperature and high pressure were not significantly different (P>0.05). In summary, high temperature and high pressure treatment could cause mT-2s to release precursor toxins, thereby enhancing its toxic effect, warning that food safety issues caused by mT-2s residues in foods of animal and plant origin cannot be ignored.
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Expression and identification of manganese peroxidase of Irpexlacteus in Schizosaccharomyces pombe and synergistic fermentation of corn straw#br# by strains and enzymes
HENG Xinyu, CUI Zhoulei, LIANG Xiaoyu, FANG Yanzhou, WU Junming, CHEN Huayou
2022, 39 (2):  63.  doi: 10.3969/j.issn. 2095-1736.2022.02.063
Abstract ( 36 )   PDF  
For the first time, a manganese peroxidase gene mnp (GenBank: MH120207.1) derived from Irpexlacteus (I. lacteus) was optimized and linked to the high-efficiency expression vector pREP without any resistance gene and Gfa gene to construct a prokaryotic-eukaryotic shuttle expression vector pREP-mnp, then electro transformed into Gfa auxotrophic Schizosaccharomyces pombe(S. pombe) to construct biosafety grade S. pombe. The expression of the target protein was verified by SDS-PAGE. The constructed engineered strain expressed MnP extracellularly, and the enzyme activity reached the peak value on the 4th day, which was 17.46 U/L. After fermentation strain screening and nitrogen source optimization, the constructed engineered strain had a significant effect of promoting lignin degradation in synergistic fermentation of corn straw. Added 0.5% urea, 2% (NH4)2SO4, 0.02% Tween-80, 0.5% CaCl2, and 0.3% MnSO4 to corn straw, the final concentration of oxalic acid in the matrix 0.5 mmol/L, S. pombe-pREP-mnp, N. crassa, S. pombe-man, C. utili, 1% Lac, and 0.4% GOD was co-fermented for 3 days. The degradation rates of lignin, hemicellulose and cellulose in corn straw were 60.79%, 27.61%, and 25.49%, respectively, and the true protein content was increased 310.99%.
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A strain of abiogenousazotobacter: screening, identification and optimization of growth conditions
WANG Ruilu, LI Jin, WANG Chong, LIU Huhu, LU Xiangyang, TIAN Yun
2022, 39 (2):  69.  doi: 10.3969/j.issn.2095-1736.2022.02.069
Abstract ( 63 )   PDF  
In order to screen and obtain stable and efficient abiogenousazotobacter, samples were selected from the soil of plant rhizosphere and silt in multiple regions, separated and screened with nitrogen-free medium, and nitrogenase activity was determined by acetylene reduction method. Morphological observation, physiological and biochemical test and 16S rDNA sequence molecular identification were made. Furthermore, the growth conditions were optimized through a combination of single factor and response surface test. The results showed that a strain of abiogenousazotobacter with nitrogenase activity of 140.14 nmol C2H4/mg·protein·hr was screened from the soil of the corn rhizosphere in Shuozhou, Shanxi Province. It was identified as Azotobacter and named Azotobacter sp. strain C-5-2; the optimal conditions for the growth of the strain were sucrose concentration 10 g/L, rotation speed 148 r/min, temperature 32 ℃ and initial pH 9.0.
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Optimization of culture conditions for furfural production from Aspergillus niger
PENG Qiuju, ZHAO Shan, SUN Ran, ZHANG Su, LI Zhu
2022, 39 (2):  74.  doi: 10.3969/j.issn. 2095-1736.2022.02.074
Abstract ( 36 )   PDF  
The response surface methodology was used to optimize the culture conditions for furfural production by Aspergillus niger (A. niger). The culture conditions of carbon source, nitrogen source, pH-value, temperature, and shaker speed were screened by the single-factor test. The key factors affecting culture conditions were studied by the Plackett-Burman (PB) test. Also, the steepest climbing experiment was used to determine the response center point of key factors, and then the optimal culture conditions were obtained by Box-Behnken method that performed response surface analysis. In this study, glucose and urea as the carbon and nitrogen source, the pH-value (7.0), temperature (26℃), and rotation speed (150r/min) were the best in the single-factor test. In the PB design experiment, glucose, urea, and pH-value were the significant factors affecting for the culture of A. niger. The optimal culture conditions were obtained by the steepest climbing experiment, the Box-Behnken method and RSM. Our results revealed that the optimized culture conditions were glucose 80g/L, urea 3.03g/L, pH-value 8.2, temperature 26℃, and rotation speed 150r/min respectively. The verification test was carried out under the optimal culture conditions. The content of furfural in A. niger was determined by high performance liquid chromatography (HPLC) after culturing 3 days, which reached 4.094μg/mL, increased by 20.2% compared to that of the pre-optimization (3.407μg/mL). Collectively, the results can provide theoretical references basis for the optimization of culture conditions for furfural production by A.niger.
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Study on the effects of different pollen load on fruit development and seed setting of Gastrodia elata
GAO Shang, CAO Xiaoyong, HU Xuanping, JIANG Jinglong, QIN Gongwei, ZHAO Yao
2022, 39 (2):  80.  doi: 10.3969/j.issn.2095-1736.2022.02.080
Abstract ( 54 )   PDF  
Pollen of orchid plants aggregates into blocks and pollinates in nature in an all-or-none manner. The effects of different pollen load on the development and seed setting of Gastrodia elata were explored. During the flowering period, the whole pollinarium was used as a control group, the pollinarium were divided into 1/2, 1/4, 1/8, 1/16 under the dissecting microscope. The fruit, seed size and weight were measured at 16 days after pollination. The results showed that different pollen load affected fruit size, weight and total seed weight of a single fruit; when the pollen load was 1/4 and below, the length, width and weight of the fruit (fresh and dry weight) were reduced significantly; the dry weight of seeds was about 0.006 g with whole pollinarium and 1/2 pollinarium pollen load, while the dry weights were about 0.003 g and 0.0016 g with 1/4 and 1/8 pollinarium, respectively; different pollen load had no effect on the seed length and the size of the embryo, the length of the seed was about 0.55 cm, and the length and width of the embryo were 0.15 cm and 0.10 cm, respectively; when the pollen load was 1/4 pollinarium and below, the seed width increased significantly, from 0.13 cm to 0.16 cm. The experiment showed that reducing pollen load affected fruit size, weight and seed width, but had little effect on the length of seeds and the size of embryos. It was speculated that the ratio of the number of pollen to the number of ovules of Gastrodia was close to 2∶1.
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Synthesis of new type magnetic flocculant and its application in the treatment of rural black-odorous water
WANG Shunyong, LI Yucheng, ZHANG Xuesheng, WANG Zhaode, LI Yonghui, SI Xinxin
2022, 39 (2):  84.  doi: 10.3969/j.issn. 2095-1736.2022.02.084
Abstract ( 37 )   PDF  
The nano Fe3O4 was modified by gallic acid(GA) and then was mixed evenly with modified chitosan to synthesize a composite magnetic flocculant mCTS@(PGA-Fe3O4), which was used to flocculate the rural black-odorous water. The flocculation effect of mCTS@(PGA-Fe3O4) under different synthetic conditions was investigated. Meanwhile, the flocculation conditions of PAM and mCTS@(PGA-Fe3O4) by response surface method were optimized. Results suggested that the optimized synthetic conditions of mCTS@(PGA-Fe3O4) were: GA dosage 0.3 g, Fe3O4 modified temperature 60℃, AM dosage 3 g, trigger mass 0.03 g and polymerization temperature 60℃. Based on the distribution of response values, the optimum operating conditions were flocculant mCTS@ (PGA-Fe3O4) 0.38 g/L, pH 7.42, and temperature 25.2℃. Under this condition, the removal rates of turbidity, color and COD were 92.0%, 84.2% and 79.9%, respectively flocculation effect was better than that of PAM.In addition, reused experiments results suggested that the flocculant still had good flocculation effect after reusing three times. This work indicated that the mCTS@(PGA-Fe3O4) possessed a good application prospect in the treatment of black-odorous water in future.
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The role of BRCA1 in homologous recombination
ZHAO Yinjun, YANG Xiaohang
2022, 39 (2):  90.  doi: 10.3969/j.issn.2095-1736.2022.02.090
Abstract ( 64 )   PDF  
On the basis of reviewing the process and products of homologous recombination (HR) repair pathway, this paper focused on the structure of BRCA1 protein and its two main functions in HR repair pathway: one is to promote DNA end resection, the other is to mediate the loading of the recombinase RAD51 at the DSB site. It was pointed out that the protein expressed by the breast and ovarian cancer-related gene BRCA1 was involved in DNA damage repair and played an important role in the HR repair pathway. Finally, the research progress of embryonic development and rescue of Brca1 mutant mice in recent years was introduced.
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Research advances in effects of microbial interaction on communities and diversity of endophytes #br#
LEI Ruifeng, Muyesaier AOSIMAN, MA Qin, Kawsar TOHTAHUN, AN Dengdi
2022, 39 (2):  95.  doi: 10.3969/j.issn.2095-1736.2022.02.095
Abstract ( 63 )   PDF  
The review discussed the symbiosis microorganisms on environmental adaptability for plants on three terms, including the factors affecting endophytic communities, the ways that microbes interact with each other, and the exogenous strains affecting the endophytic diversity. We introduced how the symbiosis with microorganisms was important for plant surviving on extremely environment, and what were the factors that affecting on the group structure of endophytes. The plants can recruit the required microbial by regulating the rhizosphere microbial communities through root exudates. And some unique groups of endophytes were established based on species and developmental stages. The successes of symbiotic of plant and microbe were the balance based on the competition and coordination among taxa, or their metabolite interactions. The inoculation of growth-promoting strains artificially or pathogen infection could also changes the structure of the groups. The emphasis is to provide reference for improving plant adaptability to adversity by using friendly microbial strains.
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Progress in research of antitumor properties of antimicrobial peptides derived from microbes
WANG Lulu, CHEN Zhou, JIA Yingmin
2022, 39 (2):  100.  doi: 10.3969/j.issn. 2095-1736.2022.02.100
Abstract ( 49 )   PDF  
This article mainly introduced the latest research progress of antimicrobial peptides (AMPs) from microorganisms in anti-tumor cells in recent years. Firstly, the types of tumor cells inhibited by AMPs from bacterial, fungal and actinomycetes sources, the characteristics of resistance of AMPs to different types of tumor cells, and the resistance effects and differences of AMPs to tumor cells were analyzed successively. Secondly, the research status of anti-tumor cell mechanism of microbial AMPs was briefly introduced, and the mechanism of inducing tumor cell apoptosis by acting on mitochondria, endoplasmic reticulum and death receptors of tumor cells was also clarified. According to this paper, the microbial source AMPs anti-tumor effect and its effect were related to the research content and the summary of the mechanism of resistance of tumor cells. It would help others more in-depth and comprehensive understanding of the microbial source AMPs new functions and point out the importance of further excavating microbial source AMPs for anti-tumor research and application of microbial source AMPs in the future to provide new ideas.
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Single-neuron recordings in dorsal cochlear nucleus of awake mouse
QIN Chunhui, TANG Zhengquan
2022, 39 (2):  106.  doi: 10.3969/j.issn.2095-1736.2022.02.106
Abstract ( 50 )   PDF  
To explore the extracellular recordings of single unit in the deep brain regions of awake mice, we recorded the neural activity of dorsal cochlear nucleus in awake head-fixed mice using glass micropipettes, and compared with that using brain-slice patch-clamp recordings. The extracellular single-cell recording results showed that principal neurons in dorsal cochlear nucleus were identified: fusiform cells showed spontaneous spike discharge activity at resting potential, “V” shape of sound-induced response frequency tuning curve(FTC), buildup response of post-stimulus time histogram (PSTH), and selectively response to sound vocalizations. Consistent with the results obtained using brain-slice patch-clamp recordings, fusiform cells identified by this extracellular single-unit recording showed spontaneous discharge activity. The neural activity of fusiform cells at rest was different from those of two classes of interneurons in the dorsal cochlear nucleus: cartwheel cells fired spontaneously a burst of spikes at rest; vertical cells remained silent at rest. Therefore, this study suggested that this extracellular single unit recording could be used to identify different cell types in deep brain regions in vivo.
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Establishment of determination method and optimization of fermentation conditions of erucamide in Bacillus megaterium L2
TANG Xinxin, XIE Yudan, XIAO Yang, SUN Ran, LI Zhu, DENG Li, YAO Jiangpang
2022, 39 (2):  110.  doi: 10.3969/j.issn.2095-1736.2022.02.110
Abstract ( 50 )   PDF  
A method for the determination of erucamide in B. megaterium L2 was established by gas chromatography-mass spectrometry (GC-MS), and then single factor experiments and response surface methods were used to study the fermentation medium and fermentation conditions. Design-expert 8.06 was used to design a three-factor response surface experiment for peptone addition, temperature, and pH. The response value was erucamide yield, and finally response surface analysis was performed. Under GC-MS chromatographic conditions, the erucamide content and peak area showed a good linear relationship (R2=0.9974), the relative standard deviations (RSD) of precision, repeatability and stability were all lower than 10%, and the recovery rate was 82.78%-98.14%, and the content of erucamide in the fermentation broth of B. megaterium was determined to be 0.940 mg/L. The optimal fermentation conditions were as follows: glucose concentration of 5 g/L, peptone concentration of 16.40 g/L, NaCl concentration of 3 g/L, inoculation 2.0%, culture temperature 34.8 ℃, shaking speed 150 r/min, initial pH 5.80. Under these conditions, the yield of erucamide was 1.325 mg/L, which was 39.03% higher than that before optimization. It can provide a reference for the determination of erucamide in B. megaterium. The fermentation medium and conditions of B. megaterium L2 significantly increased erucamide production, they provided reliable support for the subsequent research of erucamide.
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Carry out the PAD teaching reform of genetics experiment through project-driven assited by MOOC platform
LI Ping, LUO Yuxiu, SI Jianping, ZHAO Weimin, DUAN Ruijun
2022, 39 (2):  116.  doi: 10.3969/j.issn.2095-1736.2022.02.116
Abstract ( 46 )   PDF  
In order to improve the biological professional talent goals, in the course of “genetics experiment”, college of ecological and environmental engineering carried out and innovated education and teaching reform from the aspects of experimental teaching concept, experimental teaching method and assessment method, by introducing the teaching concept of “Presentation-Assimilation-Discussion”, using the MOOC platform and the “project-driven” teaching mode, paying attention to the process assessment, carrying out comprehensive discussion learning and promoting students’ internalization and absorption. Through enhancing preview with a MOOC before class-teachers teach (assign project tasks)-internalized absorption (students to carry out the experiment)-discussion and summary (teacher-student mutual effect for the program) teaching mode, students’ interests were cultivated in active learning, full playing to their subjective initiative, cooperating with ideological and political education. It reshaped students’ correct outlook on life and values. Therefor, the effect of experimental teaching improved the quality of personnel training.
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Research on establishment of experiment for observing of microfilament by fluorescence labeling in general elective course
WANG Honggang, WEI Yuan, LIU Wei, LI Dengwen, ZHAO Liqing
2022, 39 (2):  120.  doi: 10.3969/j.issn.2095-1736.2022.02.120
Abstract ( 44 )   PDF  
The course group takes onion bulbs as the experimental materials to establish the experiment of observing of microfilaments by fluorescence labeling in the general elective course of the introduction to basic life science experiment. In this experiment, the microfilaments in the inner epidermis cells of onion are labeled by the phalloidin-rhodamine. Under the fluorescence microscope, the students can observe that the microfilaments in the onion inner epidermal cells emit red fluorescence. The microfilaments fill the whole cell and are interweaved with each other. Around the nucleus, the microfilaments are denser. According to the characteristics of general elective course, onion is used instead of animal cells as experimental material, which reduces the difficulty of experimental operation. The experiment helps the non-biological majors to enhance their understanding of the frontier knowledge and experimental technology of life science, and cultivate their interest in life science by interpreting the basic knowledge of cytoskeleton, microfilaments and fluorescent labeling technology and training the experimental method of labeling microfilaments withphalloidin-rhodamine. At the same time, it enriches the experimental contents, improves the teaching quality of the course and obtains good effects.
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The value implication and practice exploration of the open course construction of biology frontier and progress
2022, 39 (2):  122.  doi: 10.3969/j.issn.2095-1736.2022.02.122
Abstract ( 48 )   PDF  
The age of information technology promotes the process of online open courses in higher education and provides a new teaching model for the teaching reform of higher education in China.Progress graduate courses with the university biology frontier online integration construction are of important value significance, and mainly reflected in the following three aspects: providing an important opportunity for the graduate student’s independent learning, providing an important platform for the development of scientific thinking ability, and developing scientific thinking ability of providing an important platform.Based on the preliminary construction experience, the course construction needs to focus on the formulation of course objectives, the selection of characteristic teaching content and the implementation of teaching activities strategy.
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xploration and practice of genetic engineering experiment teaching based on the combination of virtual and practical operation
ZHANG Yanan, WANG Chun, ZHU Xiuyun, ZHANG Xingwang, WU Xiaomin
2022, 39 (2):  125.  doi: 10.3969/j.issn.2095-1736.2022.02.125
Abstract ( 53 )   PDF  
Based on the provincial bioengineering virtual simulation laboratory (VSL), we took molecular cloning and in vitro expression experiment of functional genes as an example to carry out the genetic engineering experiment teaching. An assessment and evaluation method combining virtual experiment with real experiment was constructed and practiced based on the principles of combining process with result and teacher evaluation with online and offline self-evaluation. The advantages of virtuality and reality combination in the gene engineering experiment teaching were assessed by comparing the students’ virtual operation and test score and investigating their satisfaction with this teaching mode. It was mainly embodied in the following four aspects: expanding the time and space of experimental learning and improving students’ learning effect; realizing the sharing of virtual and real resources and cultivating students’ information literacy; student-centered teaching and strengthening the ability of independent learning; diversified evaluation to achieve the purpose of promoting leaning by evaluation.
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