Abstract: Objective To explore endogenous LINE-1 expression during Neural progenitor cells (NPCs) differentiation. Method recombinant LINE-1 ORF1 protein was expressed in bacteria, followed by purification, and the purified protein was used to immunize rabbits to produce anti-ORF1 polyclonal antibody. The antibody was used to detect LINE-1 retrotransposition during neural progenitor cells (NPCs) differentiation by Western blotting. Result The anti-ORF1 antibody possessed high sensitivity and specificity, and observed the variability of LINE-1 retrotransposition in different eukaryotic cell lines. Using anti-ORF1 antibody to detect LINE-1 ORF1 protein level during NPC differentiation, it was found that when stem cells commits to NPCs, LINE-1 retrotransiposition increases in the early stage and decline in the late stage. Conclusion LINE-1 retrotranspose increases upon neuronal commitment, suggested LINE-1 play a pivotal role in neural development.

Key words: LINE-1, retrotranspostion, neural progenitor cells