Analysis of the prion mechanism using immortalized prionless neuronal cell

Prion是一种与遗传性神经退行性疾病有关的细胞蛋白(PrPc)，这种蛋白存在于大脑神经元的外表面。虽然PrPc的功能尚未完全阐明，但它似乎具有重要的生理意义，因为到目前为止，在所有被研究的哺乳动物中都发现了PrPc基因。从Prn-p基因靶敲除小鼠胚胎和野生型建立前体细胞系将是一个有价值的模式系统，以澄清PrPc是否与这两个细胞系统的假定发育差异有关，并验证在胚胎发育早期是否存在补偿基因控制机制。从这种以基因为靶标的小鼠身上，海马细胞被永生化，并获得了克隆。由于PrPc是一种神经性蛋白，在海马神经细胞中的比例很高，而且体内的神经发生更倾向于发生在发育早期，因此在胚胎第14天从小鼠胚胎的脑中分离到了海马区。

Prion is a cellular protein (PrPc) which has been implicated in transmissible neurodegenerative disease This protein is found on the outer surfaces of neurons of the brain. Although the PrPc function has still not been completely clarified, it seems to be physiologically important because its gene has been found in all mammal examined so far. The establishment of progenitor cell lines from Prn-p gene-target knock out mice embryos and from the wild type would be a valuable model system to clarify if PrPc is related with putative differences in the development of those two cell system and also to verify if there is presence of compensatory gene control mechanisms early in embryogenesis.Mice homozogous for disrupted Prn-p genes have been generated (Bueler et al. 1987).From this type of gene-targeted mice, hippocampal cells have been immortalized and clones were obtatined. The hippocampus has been dissected from brain of mouse embryos at embryonic day 14, as the PrPc is predominantly a neuronal protein, presented in a high proportion of hippocampus nerve cell, and that the neurogenesis in vivo are prefferentially occuring at early development.Twenty eight clones were obtained and has been characterized as prionless and neuronal origin.