蛙皮素样肽家族及其受体氨基酸序列信息学比较分析

【目的】研究反刍动物蛙皮素样肽家族多肽及其受体的保守性。为不同动物,特别是反刍动物这2种蛙皮素样多肽及其受体蛋白抗原设计和活性多肽筛选等研究提供参考。【方法】采用生物信息分析学的方法,通过UniProt数据库比较牛的蛙皮素样肽家族胃泌素释放肽(Gastrin-releasing peptide, GRP)和神经介素B(Neuromedin B, NMB)2种多肽及其特异性受体GRP-R和NMB-R与其他动物氨基酸序列的差异性。【结果】13种动物成熟GRP多肽C-端的8个氨基酸序列完全相同,牛GRP氨基酸序列与绵羊、猪和豚鼠最高,分别为88.7%、77.8%和77.8%,与其他动物相似性低于74.1%。10种动物成熟NMB多肽C-端10个氨基酸序列完全相同。牛GRP-R与狗、马和猪等相似性最高,分别为96.1%、94.3%和94.0%,牛NMB-R与猪、人和马相似性最高,分别为92.3%、91.5%和91.0%;牛GRP-R与NMB-R相似性仅为62.2%。【结论】GRP和NMB的C-端氨基酸序列在不同动物之间均具有高度的保守性,而N-端为变化区域,且GRP-R和NMB-R氨基酸序列在动物之间保守性较高。     

膜联蛋白B1在猪囊尾蚴免疫逃避作用的研究进展

膜联蛋白是一类有效的内源性调节蛋白,在Ca²⁺存在的条件下与膜磷脂结合,参与细胞活动的多种功能,其与肿瘤发生、自身免疫性疾病、病毒和寄生虫感染等密切相关。作为膜联蛋白家族成员Annexin B1具有独特的氨基酸残基结构,与不同种属的寄生虫入侵特异性宿主密切相关。本文主要阐述了膜联蛋白的种类及膜联蛋白B1在猪囊尾蚴感染宿主机体过程中免疫逃避的作用,旨在探索其猪囊尾蚴感染的免疫逃避机制。深入对膜联蛋白B1和囊尾蚴之间相互关系的进一步了解,以及膜联蛋白B1在寄生虫免疫中更深入的研究,对寄生虫免疫逃避的生物学意义和寄生虫病诊断治疗提供了相关的策略。     

Reduction in cadmium accumulation in japonica rice grains by CRISPR/Cas9-mediated editing of OsNRAMP5

Cadmium (Cd) intake is harmful to human health and Cd contamination in rice grains represents a severe threat to those consuming rice as a staple food. Knockout of Cd transporters is a promising strategy to reduce Cd accumulation in rice grains. OsNRAMP5 is the major transporter for Cd and manganese (Mn) uptake in rice. Nevertheless, it is uncertain whether knockout of OsNRAMP5 is applicable to produce low Cd rice without affecting plant growth and grain yield. In this study, we adopted CRISPR/Cas9-based gene editing technology to knock out OsNRAMP5 in two japonica varieties. We generated three independent transgene-free osnramp5 mutants and investigated the effect of osnramp5 mutations on Cd accumulation and plant growth. Hydroponic experiments showed that plant growth and chlorophyll content were significantly reduced in osnramp5 mutants at low Mn conditions, and this defective growth in the mutants could be fully rescued by supply of high levels of Mn. Cd and Mn accumulation in both roots and shoots was markedly reduced in the mutants compared to that in wild-type plants. In paddy field experiments, although Cd in flag leaves and grains was greatly reduced in osnramp5 mutants, some agronomic traits including plant height, seed setting rate, and grain number per panicle were affected in the mutants, which ultimately caused a mild reduction in grain yield. The reduced plant growth in the mutants can be attributed to a marked decrease in Mn accumulation. Our results reveal that the manipulation of OsNRAMP5 should be treated with caution: When assessing the applicability of osnramp5 mutants, soil pH and soil water content in paddy fields need to be taken into consideration, since they might affect the levels of available Mn in the soil and consequently determine the effect of the mutation on grain yield.     

Sublytic C5b-9 induces protective autophagy in cultured podocytes

AIM: In podocytes, autophagy occurs at a high basal level and dysregulated autophagy is associa-ted with a variety of podocytopathies. This paper is to investigate the role of autophagy in sublytic C5b-9-induced podocyte injury. METHODS: Sublytic complement C5b-9 stimulation was used as an in vitro model. Autophagosomes were confirmed using monodansylcadaverine (MDC) staining. Immunoblotting was used to measure the change of autophagy-related markers. Cellular morphological changes were observed by Wright-Giemsa staining. Immunofluorescence staining and confocal microscopy were used to detect the expression and distribution of nephrin. The cell viability was assessed by methylthiazol tetrazolium (MTT) assay. The cell apoptosis was assessed by Annexin V-fluorescein isothiocyanate/PI staining. RESULTS: For ensuring sublytic complement injury, the maximal amounts of anti-podocyte antiserum and 160×-diluted normal human serum were used without inducing cell lysis (defined as >5% LDH release). Sublytic C5b-9 promoted autophagy of podocytes in vitro. The proautophagic effect of sublytic C5b-9 manifested in the form of accumulated MDC-labeled vesicles and enhanced the expression of LC3-Ⅱ. Autophagy inhibitor 3-methyladenosine (3-MA) promoted sublytic C5b-9-induced podocyte morphological abnormalities. Compared with the sublytic C5b-9-injured podocytes, 3-MA exposure further decreased the expression of nephrin. 3-MA enhanced sublytic C5b-9-induced podocyte apoptosis. CONCLUSION: Sublytic C5b-9 attack induces autophagy, which may play a protective role against complement-mediated podocyte injury.     

Herbicide options for effective weed management in dry direct-seeded rice under scented rice-wheat rotation of western Indo-Gangetic Plains

Farmers' participatory field trials were conducted at Madhuban, and Taraori, the two participatory experimental sites/locations of the Cereal Systems Initiative for South Asia (CSISA), a collaborative project of IRRI and CIMMYT in Karnal district of Haryana, India, during Kharif (wet season) 2010 and 2011. This research aimed to evaluate preemergence (PRE) and postemergence (POST) herbicides for providing feasible and economically viable weed management options to farmers for predominant scented rice varieties. Treatments with pendimethalin PRE fb bispyribac-sodium + azimsulfuron POST had lower weed biomass at 45 days after sowing (DAS). At Madhuban, highest grain yield of scented basmati rice (3.43 t ha⁻¹) was recorded with the sequential application of pendimethalin PRE fb bispyribac-sodium + azimsulfuron POST. However, at Taraori, yields were similar with pendimethalin or oxadiargyl PRE fb bispyribac-sodium and/or azimsulfuron POST. Applying oxadiargyl by mixing with sand onto flooded field was less effective than spray applications in non-flooded field. The benefit-cost ratio of rice crop was higher with herbicide treatments at both sites as compared with the non-treated weed-free check except single PRE and POST applications and sequential application of oxadiargyl PRE fb oxadiargyl PRE. In a separate experiment conducted at Nagla and Taraori sites, scented rice cultivars' ('CSR 30′ and 'Pusa 1121′) tolerance to three rates of azimsulfuron (15, 25, and 35 g ai ha⁻¹) was evaluated over two years (2010 and 2011). CSR 30 (superfine, scented) was more sensitive to higher rates (35 g ai ha⁻¹) of azimsulfuron as compared to Pusa 1121 (fine, scented). Crop injuries were 8 and 28% in case of CSR 30; 5 and 15% in Pusa 1121 when applied with azimsulfuron 25 and 35 g ai ha⁻¹, respectively. Azimsulfuron applied at 35 g ai ha⁻¹ reduced yield in both cultivars but in CSR 30 yield reduction was twofold (11.5%) as that of Pusa 1121 (5.2%).     

Fusarium solani Upregulated Sesquiterpene Synthase Expression,Sesquiterpene Production and Allelopathic Activity in Piper betle L.

Activators of sesquiterpene synthase (STS) gene expression and sesquiterpene production in Piper betle L. were examined using quantitative real time PCR and gas chromatography mass spectrometry methods, and the allelopathic activity of untreated and Fusarium solani-treated betel extracts was tested on seed germination and on the shoot and root growth of Thai rice variety PSL2 (Oryza sativa cv. Phitsanulok 2) and three dominant paddy weeds (Eclipta prostrata, Echinochloa crus-galli and Chloris barbata). The results demonstrated that F. solani dramatically upregulated STS expression and productions of β-cubebene, β-caryophyllene and germacrene D sesquiterpene when compared with the untreated control, and that betel extracts had a greater inhibitory effect on weeds than on rice. The effects were more clearly detected on seed germination and root growth than on shoot growth, and they were found to be dose-dependent. It is also noted that F. solani-treated extract had stronger effects than the untreated extract. The species most sensitive to the allelopathic effects was C. barbata, germination of which was completely inhibited even at a dose of 0.1 mg/mL untreated extract. With regards to rice, although betel extract at 1.0 mg/mL showed no inhibition on germination, it affected the elongation of rice roots, in addition to those of the tested weeds. The obtained data suggested that F. solani has potential as an activator of sesquiterpene allelochemical production via STS expression, the latter leading to the treated betel extract having a stronger phytotoxic effect. These results were beneficial in the promotion of natural herbicide production using biotechnology.     

利用CRISPR/Cas9和λ-Red级联技术构建产肠毒素大肠杆菌LT敲除菌株

本研究旨在利用CRISPR/Cas9和λ-Red级联的技术对产肠毒素大肠杆菌（enterotoxigenic Escherichia coli，ETEC）K88的热不稳定性肠毒素（heat-labile toxin，LT）基因进行无痕敲除并获得K88 LT^-缺陷菌株。通过序列比对获取LT两端同源序列，并构建包含LT边界、氯霉素筛选标记、sgRNA和LT同源臂的供体片段；将供体片段转化至ETEC K88，同时分别利用λ-Red同源重组系统和CRISPR/Cas9基因编辑系统，对LT基因进行敲除；通过PCR验证获得了K88 LT^-缺陷菌株，并通过试验测定了敲除菌株的溶血能力和生长曲线。结果显示，λ-Red同源重组系统可成功地将LT基因替换为相应的供体片段，CRISPR/Cas9基因编辑系统可高效地对筛选标记进行删除，最终通过λ-Red和CRISPR/Cas9结合的基因编辑系统可成功对ETEC K88的LT基因进行无痕敲除。体外试验结果表明，K88 LT^-缺陷菌株的溶血能力丧失，并且生长速度比野生型菌株减缓，LT可能和ETEC K88的致病能力和生长性能有关。表明λ-Red和CRISPR/Cas9级联的基因敲除方法可用于LT毒素基因及其他一些大肠杆菌基因的敲除。K88 LT^-缺陷菌株的构建为下一步研究LT毒素的致病机制奠定基础。     

基于XML的科研管理信息系统研究

该文在分析农业科研单位科研管理现状的基础上,提出了一种基于XML技术的科研管理信息系统,并进一步介绍了系统采用的B/C/S结构模型,阐述了系统的功能模块和系统实现的部分关键技术。得出该系统能降低对客户端的要求,减少系统的通讯量,使得数据的呈现、交互更加容易,从而提高了科研管理工作的效率。     

肌细胞增强因子2B基因在人和动物中的研究进展

肌细胞增强因子2B(MEF2B)基因属于肌细胞增强因子2(MEF2)基因家族成员,广泛表达于人和动物的肌肉和神经组织中,在肌肉生成、神经系统发育和分化、肝脏纤维化等方面具有重要的作用,作者从MEF2B基因的结构、组织分布、生物学功能及研究进展等方面对该基因进行了综述.