目的 探讨鸡胚发育过程中，音猬因子（Shh）基因在脊髓中超表达后对配对框（Pax）基因家族Pax3、Pax6以及Pax7蛋白表达的影响。 方法 在鸡胚龄2.5～3.0d（E2.5～E3）时，实验组利用鸡胚脊髓活体电转基因技术将携带Shh基因的质粒和携带有绿色荧光蛋白（GFP）报告基因的质粒共转入鸡胚脊髓，对照组则只转入报告基因质粒。E4时取材，每组至少取3例，冷冻切片后采用原位杂交技术检测Shh基因的mRNA表达水平，利用荧光免疫技术检测Shh在鸡胚脊髓中超表达后对Pax3，Pax6以及Pax7蛋白表达水平的影响，并将对照组及实验组中3种基因在脊髓两侧的表达量进行统计学分析。 结果 原位杂交结果表明，E4时Shh的mRNA主要表达在脊髓底板和脊索，实验组结果显示，利用鸡胚脊髓活体电转技术成功建立了Shh超表达模型。对照组中荧光免疫结果表明，Pax3主要表达于脊髓翼板、生肌节、背根以及背根神经节；Pax6主要表达于跨越翼板和基板的脊髓中间部位；Pax7则主要均匀表达于翼板、顶板和生肌节。Shh超表达后，脊髓转染侧与未转染侧相比Pax3、Pax6以及Pax7的表达量差异极显著（P<0.01），这3种基因在脊髓中的表达均被抑制。 结论 在鸡胚发育过程中，Pax家族Pax3、Pax6以及Pax7 3种基因在鸡胚脊髓中具有不同的表达模式，Shh超表达后对其均具有明显的抑制作用，显示这3种Pax基因受Shh信号通路调控。

Objective To study the effect of sonic hedgehog (Shh) gene overexpression on Pax family in the spinal cord during chicken embryonic development.
Methods At E2.5-E3, Shh expression plasmids and green fluorescence protein (GFP) reporter gene plasmids were co-transfected into chicken embryonic spinal cord by in vivo electroporation. Only GFP reporter gene plasmids were transfected by the same way as control. Samples were collected from three or more embryos from the experimental and control groups and sliced at E4. Thenin situhybridization was used to detect whether Shh was really overexpressed. Immunofluorescence histochemistry was used to study whether Pax3, Pax6 and Pax7 were regulated by the overexpressed Shh.Statistical software was utilized to analyze the expression quantity of Pax3, Pax6 and Pax7 between two sides of the chicken spinal cords in the control and experimental group. Results The results ofin situhybridization showed that Shh was mainly expressed in the floor plate and notochord and the overexpression model of Shh in chicken spinal cord was built successfully in the experimental group. The immunohistochemical positive staining for Pax3 was distributed in alar plate,dermatome, dorsal root and dorsal root ganglion in the E4 chicken embryo spinal cord. The immunofluorescence positive signal for Pax6 was in the middle of spinal cord across the alar plate and the basal plate. The signal of Pax7 mainly existed evenly in the alar plate roof plate and dermatome. There was highly significant difference between electroplated side and normal side (P<0.01). The expressions of Pax3, Pax6 and Pax7 were all depressed by Shh overexpression. Conclusion There are different expression patterns in Pax3,Pax6,and Pax7 in the developmental chicken spinal cord, and the intensities of immunofluorescence positive signal for these genes are decreased by Shh overexpression, which indicates that they are regulated by Shh signal pathway.