用聚赖氨酸包被国产载玻片制作DNA芯片

用多聚赖氨酸对国产载玻片进行包被处理,在不同的固定条件下,比较其与进口多聚赖氨酸载玻片对大片段DNA和3′端氨基修饰寡核苷酸的固定效果.结果表明,在DNA固定率上,自行包被处理的国产载玻片与进口多聚赖氨酸载玻片没有显著差异;紫外交联对大片段DNA固定率影响显著,但对氨基修饰的寡核苷酸影响不显著;3种点样液中,进口点样液MSS点样效果最好,其次为3×SSC,第三是水.氨基修饰的寡核苷酸可以很好地固定在聚赖氨酸包被的载玻片上.     

p53 inhibits the proliferation of male germline stem cells from dairy goat cultured on poly-L-lysine

Male germline stem cells (mGSCs) can transmit genetic materials to the next generation and dedifferentiate into pluripotent stem cells. However, in livestock, mGSC lines are difficult to establish, because of the factors that affect their isolation and culture. The extracellular matrix serves as a substrate for attachment and affects the fate of these stem cells. Poly-L-lysine (PL), an extracellular matrix of choice, inhibits and/or kills cancer cells, and promotes the attachment of stem cells in culture. However, how it affects the characteristics and potentials of these stem cells in culture needs to be elucidated. Here, we isolated, enriched and cultured dairy goat mGSCs on five types of extracellular matrices. To explore the best extracellular matrix to use for culturing them, the characteristics and proliferation ability of the cells were determined. Results showed that the cells shared several characteristics with previously reported mGSCs, including the poor effect of PL on their proliferative and colony-forming abilities. Further examination showed upregulation of p53 expression in these cells, which could be inhibiting their proliferation. When a p53 inhibitor was included in the culture medium, it was confirmed to be responsible for the inhibition of proliferation in mGSCs. Optimal concentration of the inhibitor in the culture of these cells was 5 µM. Furthermore, addition of the p53 inhibitor increased the expression of the markers of self-renewal and cell cycle in goat mGSCs. In summary, suppressing p53 is beneficial for the proliferation of dairy goat mGSCs, cultured on PL.     

多聚赖氨酸-硅纳米的制备及体外转染HepG2细胞的研究

目的观察多聚赖氨酸-硅纳米颗粒作为基因转染载体体外转染肝癌细胞系HepG2细胞的可行性。方法自制硅纳米颗粒并用多聚赖氨酸修饰,与增强型绿色荧光蛋白基因质粒(pEGFP-C1)结合后体外转染HepG2细胞,观察转染后绿色荧光蛋白表达情况,计算转染效率。结果制备出大小均匀、粒径30 nm、稳定性及分散性好的球形硅纳米,硅纳米表面经多聚赖氨酸修饰后作为基因转染载体,能有效地转染pEGFP-C1进入HepG2细胞,转染效率为30%~40%。结论本文成功制备了多聚赖氨酸-硅纳米,该纳米颗粒在体外可作为基因载体,有效转染质粒pEGFP-C1。