Pooled CRISPR/Cas9 reveals redundant roles of plastidial phosphoglycerate kinases in carbon fixation and metabolism

Phosphoglycerate kinase (PGK) is a highly conserved reversible enzyme that participates in both glycolysis and photosynthesis. In Arabidopsis thaliana, one cytosolic PGK (PGKc) and two plastidial PGKs (PGKp) are known. It remains debatable whether the two PGKp isozymes are functionally redundant or specialized in plastidial carbon metabolism and fixation. Here, using a pooled clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR‐associated protein 9 (Cas9) strategy, we found that plants with single mutations in pgkp1 or pgkp2 were not significantly affected, whereas a pgkp1pgkp2 double mutation was lethal due to retarded carbon fixation, suggesting that PGKp isozymes play redundant functional roles. Metabolomic analysis demonstrated that the sugar‐deficient pgkp1pgkp2 double mutation was partially complemented by exogenous sugar, although respiration intermediates were not rescued. Chloroplast development was defective in pgkp1pgkp2, due to a deficiency in glycolysis‐dependent galactoglycerolipid biosynthesis. Ectopic expression of a plastid targeting PGKc did not reverse the pgkp1pgkp2 double‐mutant phenotypes. Therefore, PGKp1 and PGKp2 play redundant roles in carbon fixation and metabolism, whereas the molecular function of PGKc is more divergent. Our study demonstrated the functional conservation and divergence of glycolytic enzymes.     

复苏植物旋蒴苣苔J结构域蛋白编码基因BhDNAJC2的 克隆、表达与功能

热激蛋白(HSP)是一类在受到逆境刺激后大量表达的蛋白质, 能够帮助蛋白质正确折叠, 促使变性蛋白质降解, 缓解逆境胁迫对生物体的损伤。为揭示热激蛋白在耐旱的复苏植物中的保护作用, 该研究对复苏植物旋蒴苣苔(Boea hygrometrica)HSP40家族中J结构域蛋白BhDNAJC2的编码基因进行了克隆、表达与功能分析。Real-time PCR检测表明, 该基因受脱水、低温、热激等多种逆境条件和脱落酸(ABA)诱导表达。BhDNAJC2-YFP定位于细胞质、内质网和细胞核。过表达BhDNAJC2的拟南芥(Arabidopsis thaliana)株系在干旱、热激、盐胁迫和碱胁迫下均表现出明显的抗逆性。综上所述, BhDNAJC2可能在旋蒴苣苔抗旱、耐热及耐盐碱等胁迫反应中起关键作用。     

Nogo A和srGAP蛋白在NIH 3T3细胞中的共表达

为检测Nogo A和srGAPs蛋白在NIH 3T3细胞上的表达,应用Western印迹的方法检测Nogo A蛋白的表达. 从NIH 3T3细胞抽提物中检测到约230 kD特异性的Nogo A反应条带;利用双重免疫细胞荧光化学标记法和激光共聚焦显微镜成像技术分别检测Nogo A与srGAPs或Rho蛋白在NIH 3T3细胞上的共表达状况,可观察到Nogo A与srGAPs共存于3T3细胞的细胞浆、突起和生长锥样结构上,亦可观察到Nogo A与Rho蛋白的共存.结果表明,NIH 3T3细胞中共表达Nogo A、srGAPs和Rho分子. 这为研究Nogo A与Rho信号转导途径间的关系奠定了基础.     

人源乳酸菌对2型糖尿病小鼠的缓解效果

为考察人源乳酸菌(发酵乳杆菌Lactobacillus fermentum 11、305和植物乳杆菌Lactobacillus plantarum 22、25)对2型糖尿病的缓解效果,对2型糖尿病小鼠连续灌胃菌粉溶液12周.每周记录各组小鼠体重、进食量和血糖.实验结束前进行口服葡萄糖耐量试验和胰岛素抵抗试验.实验结束后...     

三聚氰胺胶体金免疫层析试纸条的研制

通过胶体金免疫层析技术建立一种特异、便捷、快速的三聚氰胺抗原检测方法,对奶制品及饲料中的三聚氰胺残留水平监测提供参考。用柠檬酸三钠还原法制备的胶体金,标记纯化的三聚氰胺单克隆抗体,喷于试纸的金标垫。将MEL-OVA(三聚氰胺和卵清白蛋白的偶练物)和纯化的羊抗鼠IgG分别喷于试纸的T(检测线)处和C(质控线)处,通过挑选试纸条材料和调试工艺参数,并最终组装成试纸条。结果显示,制备的试纸监测体系方法检出限为50 g/L。试纸条对牛奶、奶粉和饲料中的三聚氰胺残留的检出限分别为100 g/L、100 ng/g和200 ng/g。将该法与LC-MS/MS法对比检测牛奶、奶粉和饲料样品,在试纸条检测范围内,与LC-MS/MS法检测结果一致性好,从而验证了该方法的有效性。制备的三聚氰胺胶体金检测试纸在常温干燥环境下至少可保质6个月,能够检测出三聚氰胺含量大于50 g/L的样品,适用于现场实际样品三聚氰胺残留水平监测,具有良好的应用前景。     

A 10-miRNA risk score-based prediction model for pathological complete response to neoadjuvant chemotherapy in hormone receptor-positive breast cancer

Patients with hormone receptor(HR)-positive tumors breast cancer usually experience a relatively low pathological complete response(p CR) to neoadjuvant chemotherapy(NAC). Here, we derived a 10-micro RNA risk score(10-mi RNA RS)-based model with better performance in the prediction of p CR and validated its relation with the disease-free survival(DFS) in 755 HRpositive breast cancer patients(273, 265, and 217 in the training, internal, and external validation sets, respectively). This model,pres...     

Detection and Quantification of Fusarium oxysporum f. sp. niveum Race 1 in Plants and Soil by Real-time PCR

Fusarium wilt caused by Fusarium oxysporum f. sp. niveum (Fon) is the most serious soil-borne disease in the world and has become the main limiting factor of watermelon production. Reliable and quick detection and quantification of Fon are essential in the early stages of infection for control of watermelon Fusarium wilt. Traditional detection and identification tests are laborious and cannot efficiently quantify Fon isolates. In this work, a real-time polymerase chain reaction (PCR) assay has been described to accurately identify and quantify Fon in watermelon plants and soil. The FONRT-18 specific primer set which was designed based on identified specific sequence amplified a specific 172 bp band from Fon and no amplification from the other formae speciales of Fusarium oxysporum tested. The detection limits with primers were 1.26 pg/μl genomic DNA of Fon, 0.2 pg/ng total plant DNA in inoculated plant, and 50 conidia/g soil. The PCR assay could also evaluate the relationships between the disease index and Fon DNA quantity in watermelon plants and soil. The assay was further used to estimate the Fon content in soil after disinfection with CaCN₂. The real-time PCR method is rapid, accurate and reliable for monitoring and quantification analysis of Fon in watermelon plants and soil. It can be applied to the study of disease diagnosis, plant-pathogen interactions, and effective management.     

R-藻红蛋白的结构、功能及其应用

R-藻红蛋白是最重要类型的藻红蛋白,为许多藻类的前级捕光色素蛋白,在光的激发下,能发出桔红色荧光。现对R-藻红蛋白的三维结构与功能的关系、R-藻红蛋白离体的光学活性在肿瘤光动力学治疗(PDT)中作为光敏剂和荧光免疫检测等领域作为荧光探针分子的应用进行综述。     

PKA modulates GSK-3beta- and cdk5-catalyzed phosphorylation of tau in site- and kinase-specific manners

Phosphorylation of tau protein is regulated by several kinases, especially glycogen synthase kinase 3beta (GSK-3beta), cyclin-dependent protein kinase 5 (cdk5) and cAMP-dependent protein kinase (PKA). Phosphorylation of tau by PKA primes it for phosphorylation by GSK-3beta, but the site-specific modulation of GSK-3beta-catalyzed tau phosphorylation by the prephosphorylation has not been well investigated. Here, we found that prephosphorylation by PKA promotes GSK-3beta-catalyzed tau phosphorylation at Thr181, Ser199, Ser202, Thr205, Thr217, Thr231, Ser396 and Ser422, but inhibits its phosphorylation at Thr212 and Ser404. In contrast, the prephosphorylation had no significant effect on its subsequent phosphorylation by cdk5 at Thr181, Ser199, Thr205, Thr231 and Ser422; inhibited it at Ser202, Thr212, Thr217 and Ser404; and slightly promoted it at Ser396. These studies reveal the nature of the inter-regulation of tau phosphorylation by the three major tau kinases.     

温度胁迫下越冬松针瘿蚊(Thecodiplosis japonensis)幼虫的生理生化机制(英文)

松针瘿蚊是韩国林业爆发性害虫,以 ３龄老熟幼虫在地表越冬。经冷休克（－１０ ℃和－５ ℃）和热休克（３７℃、４０℃和４５℃）处理的越冬幼虫与正常幼虫具有相同的过冷却点,保持在－２０℃左右。温度胁迫可以提高对亚致死温度（－１５℃、３ ｈ）的耐受性。对于存活率的提高,冷休克处理比热休克处理更有效。这是冷热休克能同时提高虫体亚致死温度的耐受性的第三例报道。在冷休克（－１０℃）和热休克（４０℃和４５℃）处理后,老熟幼虫表达一种特异的胁迫蛋白,分子量为 ８３ ｋＤ。本文还研究了温度胁迫对越冬老熟幼虫体内酶促与非酶促抗氧化系统的影响。温度胁迫使老熟幼虫产生氧化胁迫,而快速冷耐受（ｒａｐｉｄ ｃｏｌｄｈａｒａｅｎｉｎｇ）处理,由于体内谷胱甘肽含量的提高以及谷胱甘肽还原酶活性的增高,使之不发生氧化胁迫反应。