牛胚胎发育早期MnSOD,Glut-1,Hsp70,IGF-II,IFN-t基因表达差异的研究

目的:研究体外受精生产的牛胚胎在发育早期各个阶段MnSOD,Glut-1,Hsp70,IGF-II,IFN-t基因的表达差异,阐明体外培养胚胎发育阻滞和胎儿发育异常的分子机理和胚胎阻滞有关的目的基因,为完善体外培养系统、提高IVP胚胎质童和确保IVP后代正常发育提供理论依据.方法:提取体外生产的不同阶段牛胚胎总RNA,以β-actin基因为内对照,用半定童RT-PCR技术检测胚胎发育各时期MnSOD,Glut-1,Hsp70,IGF-Ⅱ,IFN-t基因在mRNA水平的表达情况.结果:在卵母细胞中,MnSOD及IFN-t基因呈高表达,Glut-1,Hsp70及IGF-II呈低表达;在8-16细胞、桑葚胚及囊胚中,MnSOD及IGF-II基因呈高表达,而Glut-1,Hsp70及IFN-t基因则呈低表达.     

基于转录组测序的放射性肠损伤基因动态变化

目的 探讨致死剂量的电离辐射对小鼠空肠组织转录组动态变化。方法 小鼠经14 Gy ¹³⁷Cs γ射线腹部照射后,分别于6 h,3.5和5 d提取各组小鼠空肠总RNA进行转录组测序。表达变化倍数在2倍以上即视为显著差异,对表达差异的基因进行IPA、Funrich、GO和KEGG软件分析。结果 小鼠在腹部照射后6 h和3.5 d共同激活了p53信号通路。在照射后第3.5天的差异基因中,基因相互作用网络分析结果表明,Lck、Cdk1和Fyn可能起关键作用,通路分析表明,上调了DNA损伤修复信号通路,下调了细胞黏附分子、黏着斑和IgA分泌途径信号通路。结论 p53信号通路以及Lck、Cdk1和Fyn等基因在放射性肠损伤中可能起关键作用。     

恩替卡韦耐药乙型肝炎病毒稳定复制细胞系的转录组学分析

目的 分析恩替卡韦耐药乙型肝炎病毒(ETV-r HBV)稳定转染前后宿主细胞转录组水平的基因差异表达,为后续开展HBV感染相关机制研究提供基础数据和参考.方法 对ETV-r HBV稳定转染细胞株(HepG2.A64)及其原始背景细胞株(HepG2)进行转录组测序(n=3),利用DESeq2软件以|log2 Fold C...     

In utero ultrasound backscatter microscopy of early stage mouse embryos.

A high resolution ultrasound imaging technique, ultrasound backscatter microscopy (UBM), has previously been shown to be useful for in utero imaging of mouse embryos, and for direct manipulation of mouse embryos through UBM-guided injections. UBM images from mouse embryos staged between 8.5 and 10.5 days of gestation are presented to demonstrate the range of anatomical structures which can be studied with this approach. Ultrasound contrast agents have been injected into the forebrain ventricle of 10.5 day embryos to characterize the resulting three-dimensional distribution of the injected agents. These studies provide important background data relevant to future use of this technique for in utero analysis of early brain and heart development, and for in utero manipulation of mouse embryos through UBM-guided injections.     

Adaptive response in mouse embryos?

Pre-implantation embryos of the mouse were studied for the occurrence of an adaptive response, i.e. induction of radio-resistance by a previous low dose. Various experimental designs were checked (initial doses between 3 and 10 cGy; second dose 2-6 Gy at 6-24 h after the first dose). Some of the experiments were carried out in exactly the same way that resulted in an adaptive response of human lymphocytes reported previously. However, when cell proliferation and differentiation of mouse embryos were examined, none of the conditions tested indicated the induction of an adaptive response.     

Radiotoxicity of 125I-iododeoxyuridine in pre-implantation mouse embryos.

The radiotoxicity of DNA incorporated 125I in cultured pre-implantation two-cell mouse embryos was investigated and compared with external gamma-irradiation. The uptake of 125IdU in the two-cell stage embryos was determined as a function of incubation time and concentration of radioactivity (MBq/ml) in the medium. The absorbed dose to the embryos was calculated using conventional procedures. The embryo survival curves show that the dose at 37% survival is only about 15 cGy for 125IdU, whereas for 137Cs-photons it is 175 cGy. The extreme toxicity observed is thought to be due to the localized energy deposition of the numerous low energy Auger electrons emitted in the decay of 125I. These results are consistent with earlier observations in mouse testis and cultured cells and point to the need for assessing the radiation risk from incorporated Auger electron emitting radionuclides based on their subcellular distribution.     

Three‐dimensional micro‐MRI analysis of cerebral artery development in mouse embryos

Vascular system development involves a complex, three‐dimensional branching process that is critical for normal embryogenesis. In the brain, the arterial systems appear to develop in a stereotyped fashion, but no detailed quantitative analyses of the mouse embryonic cerebral arteries have been described. In this study, a gadolinium‐based contrast perfusion method was developed to selectively enhance the cerebral arteries in fixed mouse embryos. Three‐dimensional magnetic resonance micro‐imaging (micro‐MRI) data were acquired simultaneously from multiple embryos staged between 10 and 17 days of gestation, and a variety of image analysis methods was used to extract and analyze the cerebral arterial patterns. The results show that the primary arterial branches in the mouse brain are very similar between individuals, with the patterns established early and growth occurring by extension of the segments, while maintaining the underlying vascular geometry. To investigate the utility of this method for mutant mouse phenotype analysis, contrast‐enhanced micro‐MRI data were acquired from Gli2^‐/‐ mutant embryos and their wild‐type littermates, showing several previously unreported vascular phenotypes in Gli2^?/? embryos, including the complete absence of the basilar artery. These results demonstrate that contrast‐enhanced micro‐MRI provides a powerful tool for analyzing vascular phenotypes in a variety of genetically engineered mice. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.     

抑制NO的产生对小鼠胚胎体外发育的影响

目的利用NO合酶抑制剂NG-硝基-L-精氨酸甲基酯盐酸盐（L-NAME）抑制胚胎细胞产生NO,探讨NO作为细胞功能活动的重要信使分子在早期胚胎发育中的调控作用。方法通过体外受精方式获得受精胚,将受精胚培养于添加不同浓度L-NAME的胚胎培养液中,检测胚胎发育的卵裂率、囊胚率和囊胚的总细胞数。结果 0.1mmol/L的L-NAME对胚胎的卵裂率和囊胚率没有显著影响,但囊胚的总细胞数显著降低;随着L-NAME浓度的增加,1和10 mmol/L L-NAME组胚胎的卵裂率、囊胚率和囊胚的总细胞数显著降低。结论 NO在早期胚胎发育过程中具有重要的调控作用,抑制胚胎细胞中NO的产生将严重影响早期胚胎的发育及发育质量。     

低剂量电离辐射对小鼠下丘脑cAMP、cGMP及Fos蛋白表达的影响

目的　研究低剂量辐射对小鼠下丘脑cAMP、cGMP及Fos蛋白表达的影响。方法cAMP、cGMP和Fos蛋白分别采用竞争性蛋白结合分析、放免分析和免疫组织化学法。结果　 75mGyX射线全身照射后 ,小鼠下丘脑cAMP含量迅速增高 ,15min即达峰值 ,而后迅速回降 ,1h后接近假照射水平 ,以后出现小的波动 ;cGMP含量的变化基本与cAMP的变化相反 ;Fos蛋白在下丘脑诸多神经元核团内均呈阳性 ,照射后 8h达峰值 ,12h后逐渐减少 ,48h基本恢复至假照射水平。结论　提示低剂量辐射可激活小鼠下丘脑神经元的信号传递 ,进而调节免疫系统功能。