论文部分内容阅读
During the period of neurogenesis in the spinal cord, particular types of neurons are generated from specific progenitor cells located in different dorsoventral (DV) regions of the ventricular zone.The graded morphogens along the DV axis of the neural tube confer positional information to the progenitor cells.Morphogens achieve through induction or inhibition of a set of transcription factors expression in a concentration dependent manner.By combinatorial expression of distinct transcription factors, the DV axis of the neural tube can be divided into multiple domains and cross-repressive interactions between complementary pairs of transcription factors further refine and sharpen the boundaries between adjacent domains.The action of these transcription factors directs different progenitor populations to generate particular subtypes of neurons.Sp8 is a zinc finger transcription factors belonging to specificity protein (Sp) family and expression of Sp8 in the basal plate of spinal cord has been reported.However there is no study addressing the function role of Sp8 during spinal cord development.In the present study, we first confirmed Sp8 expression in the spinal cord using immunohistochemistry.During neurogenesis in the spinal cord, Sp8 expression shares the same ventral limit with Olig2 and is complementary to Nkx2.2.Olig2+ domain and Nkx2.2+ domain are neighboring with each other, and give rise to Is11+ motor neurons and Sim1+ V3 interneurons respectively.When mouse Sp8 was overexpressed in the chick spinal cord using either retrovirus or in ovo electroporation, we found that ectopic motor neurons were induced in the Nkx2.2+ p3 domain.Meanwhile, Nkx2.2 expression was cell-autonomously repressed by Sp8 expression.This suggests that Sp8 participates in patterning the ventral spinal cord.