3H-31, A Non-structural Protein of Heliothis virescens ascovirus 3h,Inhibits the Host Larval Cathepsin and Chitinase Activities

Virologica Sinica - 3h-31 of Heliothis virescens ascovirus 3h (HvAV-3h) is a highly conserved gene of ascoviruses. As an early gene of HvAV-3h, 3h-31 codes for a non-structural protein (3H-31) of...     

一株产透明质酸酶的菌株鉴定及酶学性质研究

透明质酸酶可用于药物渗透剂、动物皮革松散及低分子量的透明质酸制备.实验室前期筛选了一株具有较高透明质酸降解能力的菌株,本研究对其进行了 16S rRNA基因和生理生化反应鉴定,鉴定为弗氏柠檬酸杆菌,但弗氏柠檬酸杆菌来源的透明质酸酶的功能还未见报道.因而,以透明质酸为底物研究其酶学性质,结果表明:该酶最适pH值为5.5,在pH值4.0～8.0下处理1 h可以保持60％以上酶活力;最适温度为50℃,在50℃和60℃下处理1h后剩余60％以上的酶活力.该酶和人源透明质酸酶最适pH相似,但其耐热性更高.因此,本研究挖掘到了新颖的透明质酸酶的资源,并为其开发利用提供了参考价值.     

屯昌猪MYLPF基因序列分析及其组织表达量检测

为获得屯昌猪MYLPF基因的CDS区序列并分析其分子结构特征,研究屯昌猪、杜洛克猪以及其杂交F1代猪不同组织中的MYLPF mRNA表达水平,本研究以GenBank上公布的猪MYLPF基因序列(登录号:NM_001006592)为参考设计引物,通过RT-PCR扩增、测序获得屯昌猪MYLPF基因CDS区.结果显示:该基因CDS区长度510 bp,编码169个氨基酸,在CDS区存在33 G＞T的同义突变;该基因编码产物既没有跨膜结构,也不存在信号肽,属于非分泌型蛋白,主要在细胞质中发挥作用,预测存在1个潜在的糖基化位点和9个磷酸化位点,α螺旋区域在预测的二级结构中占比最大.荧光定量PCR检测结果显示MYLPF基因在屯昌猪背最长肌中表达量最高,屯昌猪背最长肌中MYLPF mRNA的表达量均显著高于杜洛克猪及其杂交F1代猪.本研究为探明MYLPF基因对猪肌内脂肪的影响提供了分子理论依据.     

中国人胎盘组织ABCB1基因多态性与P-gp表达水平的相关性

为了探讨中国人群胎盘组织中ABCB1基因单核苷酸多态性与其mRNA及蛋白表达水平的相关性,为妊娠期安全用药提供理论依据,本研究选取2016年6月至2018年5月于昆明医科大学第一附属医院正常分娩的200例中国汉族妇女的胎盘组织为研究对象,剪取母体侧胎盘组织,用于DNA、RNA和蛋白质的提取.通过测序确定ABCB1基因rs1045642、rs1128503及rs2032582多态性位点的基因型;采用实时荧光定量PCR和Western blot法测定组织中P-gp的mRNA和蛋白表达水平;对ABCB1基因多态性与P-gp的mRNA及蛋白表达水平的相关性进行分析.研究发现,对于rs1045642、rs1128503及rs2032582多态性位点,各基因型之间P-gp的mRNA及蛋白表达水平差异均无统计学意义(F=0.813,0.219,P＞0.05;F=0.132,0.086,P＞0.05;F=1.617,0.794,P＞0.05).本研究表明ABCB1 rs1045642、rs1128503及rs2032582基因多态性与中国汉族人群胎盘组织P-gp mRNA及蛋白表达水平可能无关.     

Th2 polarization in target organs is involved in the alleviation of pathological damage mediated by transplanting granulocyte colony-stimulating factor-primed donor T cells

Acute graft-versus-host disease(a GVHD) is caused by allo-activated donor T cells infiltrating target organs. As a regulator of immune function, granulocyte colony-stimulating factor(G-CSF) has been demonstrated to relieve the a GVHD reaction.However, the role of G-CSF-primed donor Tcells in specific target organs is still unknown. In this study, we employed a classical MHC-mismatched transplantation mouse model(C57BL/6 into BALB/c) and found that recipient mice transplanted with GCSF-primed T cells exhibited prolonged survival compared with that of the PBS-treated group. This protective function against GVHD mediated by G-CSF-primed donor T cells was further confirmed by decreased clinical and pathological scores in this a GVHD mouse model, especially in the lung and gut. Moreover, we found that Tcells polarized towards Th2 cells and regulatory T cells were increased in specific target organs. In addition, G-CSF treatment inhibited inducible co-stimulator(ICOS) expression and increased the expression of tolerance-related genes in recipient mice. Our study provides new insight into the immune regulatory effects of G-CSF on T cell-mediated a GVHD, especially for its precise regulation in GVHD target organs.     

Slc20a1b is essential for hematopoietic stem/progenitor cell expansion in zebrafish

Science China Life Sciences - Hematopoietic stem and progenitor cells (HSPCs) are able to self-renew and can give rise to all blood lineages throughout their lifetime, yet the mechanisms regulating...     

Diet drives convergent evolution of gut microbiomes in bamboo-eating species

Gut microbiota plays a critical role in host physiology and health. The coevolution between the host and its gut microbes facilitates animal adaptation to its specific ecological niche. Multiple factors such as host diet and phylogeny modulate the structure and function of gut microbiota. However, the relative contribution of each factor in shaping the structure of gut microbiota remains unclear. The giant(Ailuropoda melanoleuca) and red(Ailurus styani) pandas belong to different families of order Carnivora. They have evolved as obligate bamboo-feeders and can be used as a model system for studying the gut microbiome convergent evolution. Here, we compare the structure and function of gut microbiota of the two pandas with their carnivorous relatives using 16S rRNA and metagenome sequencing. We found that both panda species share more similarities in their gut microbiota structure with each other than each species shares with its carnivorous relatives. This indicates that the specialized herbivorous diet rather than host phylogeny is the dominant driver of gut microbiome convergence within Arctoidea.Metagenomic analysis revealed that the symbiotic gut microbiota of both pandas possesses a high level of starch and sucrose metabolism and vitamin B12 biosynthesis. These findings suggest a diet-driven convergence of gut microbiomes and provide new insight into host-microbiota coevolution of these endangered species.     

The novel peptide NbPPI1 identified from Nicotiana benthamiana triggers immune responses and enhances resistance against Phytophthora pathogens

In plants, recognition of small secreted peptides, such as damage/danger‐associated molecular patterns (DAMPs), regulates diverse processes, including stress and immune responses. Here, we identified an SGPS (Ser‐Gly‐Pro‐Ser) motif‐containing peptide, Nicotiana tabacum NtPROPPI, and its two homologs in Nicotiana benthamiana, NbPROPPI1 and NbPROPPI2. Phytophthora parasitica infection and salicylic acid (SA) treatment induced NbPROPPI1/2 expression. Moreover, SignalP predicted that the 89‐amino acid NtPROPPI includes a 24‐amino acid N‐terminal signal peptide and NbPROPPI1/2‐GFP fusion proteins were mainly localized to the periplasm. Transient expression of NbPROPPI1/2 inhibited P. parasitica colonization, and NbPROPPI1/2 knockdown rendered plants more susceptible to P. parasitica. An eight‐amino‐acid segment in the NbPROPPI1 C‐terminus was essential for its immune function and a synthetic 20‐residue peptide, NbPPI1, derived from the C‐terminus of NbPROPPI1 provoked significant immune responses in N. benthamiana. These responses led to enhanced accumulation of reactive oxygen species, activation of mitogen‐activated protein kinases, and up‐regulation of the defense genes Flg22‐induced receptor‐like kinase (FRK) and WRKY DNA‐binding protein 33 (WRKY33). The NbPPI1‐induced defense responses require Brassinosteroid insensitive 1‐associated receptor kinase 1 (BAK1). These results suggest that NbPPI1 functions as a DAMP in N. benthamiana; this novel DAMP provides a potentially useful target for improving plant resistance to Pytophthora pathogens.