两种复合肥在叶菜类蔬菜上的应用效果比较

在山东省莱阳和寿光两地露地及保护地生长的芹菜和大白菜上进行新型复合肥 2 1 8 11S肥效研究 ,同时与市场上较为流行的 15 15 15S复合肥进行比较。结果表明 ,2 1 8 11S复合肥比 15 15 15S复合肥在增加产量、提高品质方面效果更好。 2 1 8 11S复合肥最佳用量大白菜为 14 14～ 170 0kg·hm-2 ,芹菜为 2 0 6 2～ 2 4 78kg·hm-2 。     

Over-expression of P21 attenuates cisplatin-induced HK-2 cells injury

AIM:To investigate the effect of P21 on cisplatin-induced renal tubular epithelial cells injury.METHODS:The expression of P21 at mRNA and protein levels in cisplatin treated human renal tubular epithelial cells (HK-2) cells was determined by RT-qPCR and Western blot. Over-expression of P21in the HK-2 cells was induced by the transfection of pcDNA3-P21. The cell viability and cell apoptosis were detected by CCK-8 assay and flow cytometry, respectively. Furthermore, the protein expression of kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), caspase-3, glucose-regulated protein 78 (GRP78) and CCAAT/enhancer-binding protein homologous protein (CHOP), and phosphorylation level of eucaryotic translation initiation factor 2α (eIF2α) and protein kinase R-like endoplasmic reticulum kinase (PERK) were detected by Western blot.RESULTS:Cisplatin increased the mRNA and protein levels of P21 in a time-and concentration-dependent manner in the HK-2 cells. Over-expression of P21 inhibited cisplatin-induced cell apoptosis, and down-regulated the expression of KIM-1 and NGAL. Furthermore, Over-expression of P21 decreased the protein levels of GRP78, p-PERK, p-eIF2α, CHOP and cleaved caspase-3.CONCLUSION:Over-expression of P21 attenuates cisplatin-induced HK-2 cells injury, and the mechanism may be related to the modulation of endoplasmic reticulum stress pathway and inhibition of cell apoptosis.     

GAPB基因原核表达载体的构建

以拟南芥cDNA为模板,用PCR扩增出GAPB的基因全长,然后将GAPB基因片段连接到PET28a（＋）载体上,构建重组质粒并转化大肠杆菌DH5α,经菌落PCR和酶切鉴定筛选出阳性克隆,测序正确后,再将阳性克隆的质粒转化大肠杆菌BL21（DE3）。结果表明：成功构建了原核表达载体PET28a（＋）-GAPB,为后续的G...     

鸡、鹌鹑及其杂交禽胚胎肌肉发育过程中MSTN和p21基因的表达规律

旨在研究MSTN和p21基因在鸡、鹌鹑和杂交禽胚胎肌肉发育过程中的表达规律,比较这2个基因在杂交禽与亲本鸡和鹌鹑中的差异表达,探讨MSTN和p21基因与肌肉发育的关系。通过人工受精获得鸡(♂)与鹌鹑(♀)杂交禽蛋,与鸡蛋、鹌鹑蛋按照鸡标准孵化条件同批入孵,采集第7～17天活胚胸肌组织,应用实时荧光定量PCR技术检测MSTN和p21基因在3个物种中每一天mRNA的相对表达量。MSTN和p21基因在胚胎肌肉发育的第7～17天均有表达,这2个基因mRNA的表达在鸡胚中第9天到达第1次峰值,在鹌鹑中第7天到达第1次峰值,后都随胚胎的发育表达水平上升,并维持相对稳定的高水平表达。杂交禽的表达规律与鸡一致,也在第9天达到峰值,而p21mRNA表达极显著高于鸡和鹌鹑(P<0.01)。MSTN mRNA表达规律与成肌细胞退出细胞周期的时间规律一致;在胚胎肌肉发育过程中,MSTN基因特异性上调p21的表达。     

Expression level of the cytochrome P450c21 (CYP21) protein correlating to drip loss in pigs

Drip loss is an important meat quality trait of fresh meat affecting economic losses. The cytochrome P450c21 (CYP21) protein has a role on cortisol production and depends on stress. This might affect meat quality. The present study aimed to investigate the expression of CYP21 protein in correlation with drip loss. The samples were taken from the Longissimus dorsi muscle to evaluate drip loss (n = 300). Five muscles per group (low and high drip loss) were selected to evaluate CYP21 protein expression levels. Statistical analysis revealed that CYP21 protein expression levels were significantly difference between the drip loss groups. The high drip loss group had higher CYP21 protein expression levels than the low drip loss group (P < 0.05). Moreover, the high drip loss group had higher optical density values of the CYP21 protein band than the low drip loss group (P < 0.05). In conclusion, the expression of CYP21 protein will provide the basis for information and better understanding of the mechanisms related to drip loss in pork. Further study is warranted to validate these results in other populations.     

稳定表达山羊SLAM受体的BHK-21细胞系的建立及应用

信号淋巴激活分子(SLAM)又称为CD150,是小反刍兽疫病毒(PPRV)和犬瘟热病毒(CDV)等麻疹病毒属病毒感染淋巴细胞的主要受体,在病毒侵入细胞中发挥重要作用。为建立稳定表达山羊SLAM(g SLAM)的真核细胞系,本研究将人工合成的g SLAM基因克隆至真核表达质粒p IRESpuro3中,并在该基因的3'端引入Flag标签序列作为分子标记,构建了重组质粒p IRES3-g SLAM。将该重组质粒转染BHK-21细胞,经嘌呤霉素加压筛选及采用表达绿色荧光蛋白(GFP)的重组PPRV病毒(r PPRV/GFP)感染鉴定后,筛选到稳定表达g SLAM基因的细胞系。r PPRV/GFP感染和western blot鉴定表明,无论是否有嘌呤霉素压力的存在,该细胞系在传代至第20代,仍能稳定表达g SLAM蛋白。由于g SLAM氨基酸序列与犬的同源性较高,以表达GFP重组CDV强毒株(r CDV/GFP)感染该细胞系,病毒可以感染且能形成明显的细胞病变,表明该细胞系可用于CDV强毒分离和致弱机制等相关研究。     

用乙基环丙沙星重建受大肠杆菌污染的BHK-21细胞

为重建受大肠杆菌污染的BHK-21细胞,本研究采用药物乙基环丙沙星,先测出该药对大肠杆菌的最低抑制浓度(minimum inhibitory concentration,MIC),再测出该药对BHK-21细胞的MIC,从而确定10 mg/L为乙基环丙沙星不影响细胞生长,又能抑制大肠杆菌的安全浓度。然后用含该浓度乙基环丙沙星的MEM生长液,对受污染的BHK-21细胞进行物理、化学相结合的循环处理。经过3次循环处理,再传3代后,确认大肠杆菌污染已经被彻底清除,细胞恢复了健康。此方法为抢救受细菌污染的细胞提供了参考。     

家蚕脂蛋白基因BmLp-c21的表达分析及蛋白质亚细胞定位

家蚕30 kD脂蛋白家族在家蚕的生长发育过程中具有重要的生理功能。从家蚕蛹cDNA文库中克隆到一条编码30kD蛋白质的基因cDNA序列,该序列全长2 803 bp,ORF为792 bp,编码含263个氨基酸残基的脂蛋白(low molecular 30K lipo-protein pBmHPC-21;GenBank登录号:Q00801),命名为BmLp-c21。将BmLp-c21克隆至原核表达载体pET-28a(+),转化E.coli Rosetta(DE3),IPTG诱导表达后通过亲和层析得到纯化的融合蛋白,并免疫新西兰大白兔制备多克隆抗体。亚细胞定位显示BmLp-c21主要存在于细胞质中,呈点状或者片状分布。通过实时荧光定量PCR和Western blotting方法,分别检测到家蚕不同发育时期和5龄幼虫不同组织中BmLp-c21 mRNA的转录水平与蛋白质的表达水平存在较大差异,在蛹期及5龄幼虫血淋巴中的mRNA转录水平和蛋白质表达水平最高。初步推测BmLp-c21在家蚕蛹的变态发育过程以及蚕体脂质的运输方面具有重要的功能。     

Molecular epidemiology of Shiga toxin‐producing O113:H21 isolates from cattle and meat

The serotype O113:H21 is considered one of the relevant non‐O157 STEC serotypes associated with severe human infections. Due to the increased detection of O113 strains and their relationship with clinical cases, which emphasizes the importance of this serogroup as an emerging pathogen, our aim was to determine the characteristics of STEC O113:H21 strains circulating in bovine cattle and retail meat from Argentina. For this purpose, we determined the presence and combinations of various virulence genes (and their variants) related to adhesion and toxicity in a collection of 34 isolates. Their genetic relatedness using multiple‐locus variable‐number tandem repeat analysis (MLVA) was also studied. Subtyping of stx genes indicated that O113:H21 strains circulating in Argentina mainly present stx_2a alone or together with stx_2c or, less frequent, with stx_2d, all of which are subtypes associated with human disease. We found plasmid markers, such as saa, ehxA and subA, in a higher proportion than previous studies, and five variants of saa, two of which were novel ones. In relation to MLVA subtyping, we detected a limited diversity among the isolates considering that several loci were not discriminative and, that in some farms, the same clone seemed to remain circulating throughout the year. The O113:H21 strains studied harbour several toxin and adhesion genes (saa, espP, fimCD, ehaA, iha, hcpA, elfA, lpfO113, ecpA, subA, cdt‐V) and Stx subtypes associated with human disease. Results also highlighted that subtyping of stx and saa is useful to discriminate O113:H21 strains that share virulence genes. In conclusion, this study shows that a number of O113:H21 strains that occur in foods and bovines could be pathogenic for humans. This situation calls for further attention in the prevention and control of foodborne disease caused by these strains.