The sp7 gene is required for maturation of osteoblast-lineage cells in medaka (Oryzias latipes) vertebral column development
The sp7 gene is required for maturation of osteoblast-lineage cells in medaka (Oryzias latipes) vertebral column development
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DOI：
10.1016/j.ydbio.2017.09.010
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发表时间：
2017-11-15
影响因子：
2.7
通讯作者：
Kudo, Akira
中科院分区：
文献类型：
--
作者：
Azetsu, Yuki;Inohaya, Keiji;Kudo, Akira
Sp7是哺乳动物成骨细胞分化所必需的锌指转录因子。为了验证硬骨鱼中成骨细胞谱系细胞的特征，我们使用转录激活因子样效应核酸酶（TALEN）基因组编辑系统建立了青鳉sp7突变体。这些突变体在骨骼结构的形成中表现出严重的缺陷。特别是，神经弓和血管弓没有形成，虽然形成了索中心。对转基因青鳉的分析表明，sp7突变体在椎体周围和椎弓近端区域具有正常分布的X型胶原a（collOala）阳性的成骨样细胞。此外，在脊柱发育过程中，在椎弓上观察到runx2阳性成骨细胞祖细胞，但在椎体上没有。此外，这些成骨祖细胞分化为胶原α阳性细胞。在sp7突变体中，runx 2阳性细胞正常分布于未形成的椎弓区域，但不能分化为胶原a阳性细胞。这些结果表明，成骨细胞系细胞经历两个不同的分化过程中的发展过程中的椎弓和椎体。然而，我们的研究结果证实，成骨细胞系细胞中的sp7基因表达是分化为成熟成骨细胞以形成脊柱和其他骨骼结构所必需的。
Sp7 is a zinc finger transcription factor that is essential for osteoblast differentiation in mammals. To verify the characteristic features of osteoblast-lineage cells in teleosts, we established medaka sp7 mutants using a transcription activator-like effector nuclease (TALEN) genome editing system. These mutants showed severe defects in the formation of skeletal structures. In particular, the neural and the hemal arches were not formed, although the chordal centra were formed. Analysis of the transgenic medaka revealed that sp7 mutant had normal distribution of type X collagen al a (collOala)-positive osteoblast-like cells around the centrum and at the proximal region of the vertebral arch. The sp7 mutant phenotype could be rescued by exogenous sp7 expression in col10a1a-positive cells, as well as in sp7-positive osteoblast cells. Furthermore, runx2-positive osteoblast progenitors were observed on the vertebral arches, but not on the centrum, during vertebral column development. In addition, these osteoblast progenitors differentiated into the collOal a-positive cells. In sp7 mutant, the runx2-positive cells were normally distributed at the region of unformed vertebral arch but failed to differentiate into collOal a-positive cells. These results indicate that osteoblast-lineage cells undergo two distinct differentiation processes during development of the vertebral arch and the centrum. Nevertheless, our results verified that sp7 gene expression in osteoblast-lineage cells is required for differentiation into mature osteoblasts to form the vertebral column and other skeletal structures.