Cry2Ab蛋白对甜菜夜蛾和斜纹夜蛾低龄幼虫的抗性

【背景】在我国,由于Bt棉的种植,棉铃虫和红铃虫等靶标害虫得到了控制,但棉田其他鳞翅目害虫如甜菜夜蛾和斜纹夜蛾的危害仍较严重。美国商业化种植的双价棉BollgardⅡ所表达的Cry2Ab蛋白不仅对棉铃虫有较好的控制效果,而且对甜菜夜蛾和草地贪夜蛾有较好的控制作用。因此,该双价棉在我国被环境释放前,有必要研究其对棉田其他鳞翅目害虫的影响。【方法】在人工饲料中分别添加质量浓度为1．25、2．5、5．0、10．0和20．0μg·g^-1的Cry2Ab蛋白,采用生物测定的方法,在室内研究了其对甜菜夜蛾和斜纹夜蛾低龄幼虫存活率和体质量抑制率的影响。【结果】随着Cry2Ab蛋白浓度的增大,甜菜夜蛾初孵幼虫和1龄幼虫的存活率逐渐降低,2龄幼虫和3龄幼虫以及斜纹夜蛾各龄期幼虫的存活率在不同浓度处理下与对照差异均不显著。但与对照相比,高浓度处理对这2种害虫各龄期幼虫的体质量均有显著影响。【结论与意义】高浓度Cry2Ab蛋白（10．0和20．0μg·g^-1）对甜菜夜蛾低龄幼虫有较好的控制作用,但对斜纹夜蛾低龄幼虫的控制效果不太理想。这为该双价基因棉花在我国的推广提供了依据。     

温度对蚜科专化菌暗孢耳霉休眠孢子形成的影响

为探究虫霉休眠孢子形成的关键影响因素,通过孢子浴接种和多浓度生物测定实验,观察蚜科专化菌暗孢耳霉(Conidiobolus obscurus)在5个温度处理(10,15,20,24,28℃)和3个接种浓度梯度下感染寄主桃蚜(Myzus persicae)的情况,并观测不同处理下蚜尸内产休眠孢子的比例。暗孢耳霉对桃蚜的毒力随温度和接种浓度升高而提高。同时,感病致死的蚜尸镜检结果表明:温度显著影响休眠孢子形成,温度越高,形成几率越大;接种浓度的影响次之,在15—24℃间,形成几率随接种浓度提高而增大。这一现象可能的解释:高温环境将使寄主种群增长停滞或消退,暗孢耳霉通过感知环境温度情况,倾向于在较高温时于寄主体内形成休眠孢子来规避接下来可能出现的寄主匮乏期。     

Transgenic RNAi: Accelerating and Expanding Reverse Genetics in Mammals

Reverse genetics in mammals has relied on gene targeting strategies and has mostly been limited to the mouse. Gene targeting through homologous recombination in mouse ES cells has drawbacks which include time, expense and complexity. Recently, a new approach has been developed based on RNA-interference (RNAi) which is simpler, faster, less expensive, and should be applicable to mammalian species other than mouse. The advent of RNAi is poised to accelerate the pace at which reverse genetics can be applied to study gene function in mammals.     

原代小鼠肝脏细胞的高效分离纯化与培养*

摘要目的：建立一种能稳定获得高活力和高纯度原代小鼠肝脏细胞的分离、纯化及培养方法。方法：应用改良的Seglen 二步法原 位灌注和机械离心分离肝脏细胞,并用改良的高糖DMEM培养基进行培养。台盼蓝拒染法检测接种时肝脏细胞的存活率,倒置 显微镜动态观察肝脏细胞形态变化,应用免疫荧光技术对肝脏细胞进行Albumin 染色。结果：每只小鼠可获取肝脏细胞的总产量 平均为1.35× 106 / g体重,肝脏细胞存活率＞ 90%。倒置显微镜下观察贴壁前肝细胞直径为35.14 滋m± 4.35 滋m,肝脏细胞在接种 后3 h基本完成贴壁;肝脏细胞接种后24h,所有肝脏细胞均强阳性表达成熟肝脏细胞标志物Albumin,肝细胞纯度＞ 95%。结 论：改良的分离纯化及培养方法能稳定获得高产量、高活率及高纯度的小鼠肝脏细胞。     

MiR-26a regulates the expression of serum IGF-1 in patients with osteoporosis and its effect on proliferation and apoptosis of mouse chondrocytes

Objectives:To examine the effects of the regulation on IGF-1 by miR-26a on the serum of patients with osteoporosis (OP) and apoptosis and proliferation of chondrocytes of mice with OP.Methods:Totally 47 patients with OP treated in our hospital between July 2018 and November 2019 were selected as the research group, and 42 healthy individuals in physical examination over this period were selected as the control group. Serum was sampled from each participant in both groups, and miR-26a in the sampled serum was quantified and compared. In addition, chondrocytes were sampled from mice with OP. The changes of proliferation and apoptosis of the chondrocytes were analyzed via MTT and flow cytometry, and the levels of Caspase3, Caspase9, Bax, and Bcl-2 were quantified by western blot (WB) assay.Results:MiR-26a was expressed highly in the serum of patients with OP and chondrocytes of mice with OP, while IGF-1 was lowly expressed in them. According to the dual-luciferase reporter assay, there was a targeting correlation between miR-26a and IGF-1, and suppressing miR-26a significantly up-regulated the expression and protein level of IGF-1.Conclusions:MiR-26a can serve as a biological marker for the diagnosis of OP, and it can suppress the proliferation of chondrocytes and promote their apoptosis by regulating IGF-1.     

M16添加硫氧还蛋白过氧化物酶Ⅱ无法克服昆明小鼠早胚体外发育2-细胞阻滞

目的观察硫氧还蛋白过氧化物酶Ⅱ(Peroxiredoxin Ⅱ,PrxII)是否可以克服昆明(Kunming)小鼠早胚体外发育2-细胞阻滞。方法取昆明小鼠1-细胞胚置于含PrxII蛋白的M16培养液中培养,观察PrxII对昆明小鼠早胚发育潜能和2-细胞胚内活性氧自由基(reactive oxygen species,ROS)水平的影响;同时比较昆明和B6C3F1小鼠1-细胞胚在M16中各自的发育情况;激光扫描共聚焦显微镜分别检测比较昆明与B6C3F1小鼠体外培养2-细胞胚内ROS水平以及昆明小鼠体外培养与体内发育2-细胞胚内ROS水平。结果M16培养液中添加PrxII蛋白(1nmol/L和100nMol/L)可以明显降低昆明小鼠体外培养2-细胞胚内ROS水平(P<0.05),但不能克服昆明小鼠体外发育2-细胞阻滞;昆明小鼠1-细胞胚在M16中培养存在2-细胞阻滞现象,而B6C3F1小鼠无2-细胞阻滞现象;昆明小鼠体外培养2-细胞胚内ROS水平显著低于体内发育2-细胞胚(P<0.05),亦略低于B6C3F1小鼠体外培养2-细胞胚内ROS水平(P>0.05)。结论M16培养液中添加PrxII可以明显降低2-细胞胚...     

Bioassay and Identification of Root Exudates of Three Fruit Tree Species

A laboratory bioassay was designed to determine the aileiopathic potential of root exudates of three fruit tree species on apple germination. The results showed that root exudates of apple （Malus pumila L.） and peach （Prunus persica L.）, each at concentrations of 0.02 and 0.2 mg/L, inhibited germination and radicle growth of apple seeds by 56.7%, 60.7%, 51.5%, and 59.3%, respectively. The corresponding shoot growth inhibition rate was 49.5%, 46.7%, 36. 4%, and 44%, respectively. Root exudates of jujube （Ziziphus jujuba Mill.） had no significant effect on apple seeds. Qualitative determination of root exudates of apple, peach, and jujube tree was developed with gas chromatography-mass spectrometry. The root exudates of apple seedlings mainly contain organic acids, glycol, esters, and benzenphenol derivatives. Peach root exudates contained phenolic acids and benzenphenoi derivatives in addition to two unidentified compounds. The root exudates of jujube did not contain any phenolic acids.     

建立同时分离培养小鼠肝细胞及肝星状细胞的技术

目的:建立一种简便、经济、高产的同步分离培养肝细胞以及肝星状细胞的方法。方法:在参照国内外方法的基础上加以改良,首先采用肝脏原位胶原酶灌注消化的方法,获得总细胞悬液,经多次低速离心分离肝细胞;再用Nycodenz作为分离介质,通过密度梯度离心法从非实质细胞中得到肝星状细胞。通过台盼蓝染色方法鉴定细胞的活力,用倒置相差显微镜、立体显微镜、CK-18、白蛋白免疫荧光细胞化学染色对培养的肝细胞形态以及功能进行检测。使用Desmin、α-SMA免疫荧光细胞化学对肝星状细胞进行鉴定。结果:成功的在体外同步分离、培养肝细胞及肝星状细胞,肝细胞产率为5-6×107/只小鼠,两只小鼠肝星状细胞产率达1×106个。细胞存活率及纯度均可达90%。肝细胞在培养24h后呈不规则铺路石样形态,此为典型的肝细胞形态,其标志分子CK-18以及白蛋白免疫荧光染色阳性。倒置相差显微镜下可见贴壁后的肝星状细胞呈典型的星形细胞形态,且其标志分子Desmin、α-SMA免疫荧光染色阳性。结论:改良的原位灌注以及分离方法可以同时分离并且培养具有高活性和功能的肝细胞和肝星状细胞。