High-yield selection and extraction of two promoter-defined phenotypes of neural stem cells from the fetal human brain

Neural stem and precursor cells reside in the ventricular lining of the fetal forebrain, and may provide a cellular substrate for brain repair. To selectively identify and extract these cells, we infected dissociated fetal human brain cells with adenoviruses bearing the gene for green fluorescence protein (GFP), placed under the control of enhancer/promoters for two genes (nestin and musashi1) that are expressed in uncommitted neuroepithelial cells. The cells were then sorted by fluorescence-activated cell sorting (FACS) on the basis of E/nestin- or P/musashi1-driven GFP expression. Both P/musashi1:hGFP- and E/nestin:EGFP-sorted cells were multipotent: limiting dilution with clonal expansion as neurospheres, in tandem with retroviral lineage analysis and xenograft to E17 and P0-2 rat forebrain, revealed that each phenotype was able to both self-renew and co-generate neurons and glia. Thus, fluorescent genes placed under the control of early neural promoters allow neural stem cells to be specifically targeted, isolated, and substantially enriched from the fetal human brain.     

甲状腺转录因子-2持续表达的转基因小鼠模型建立

甲状腺转录因子-2(TTF-2)在个体发生中的表达具有高度组织特异性和发育阶段特异性,是甲状腺、腭等器官正常发育的重要调节因子。为研究TTF-2基因活动规律和表达模式发生变化,对胚胎发育过程中器官发生产生的影响,为揭示新生儿出生缺陷形成的分子机制积累资料,构建了TTF-2基因重组表达载体pBROAD3-titf-2,通过显微注射法将目的基因注入小鼠受精卵的雄原核,成功建立了TTF-2持续表达的转基因小鼠模型。