Endochondral ossification requires proper control of chondrocyte proliferation, differentiation, survival, and organization. Here we show that knockout of α-parvin, an integrin-associated focal adhesion protein, from murine limbs causes defects in endochondral ossification and dwarfism. The mutant long bones were shorter but wider, and the growth plates became disorganized, especially in the proliferative zone. With two-photon time-lapse imaging of bone explant culture, we provide direct evidence showing that α-parvin regulates chondrocyte rotation, a process essential for chondrocytes to form columnar structure. Furthermore, loss of α-parvin increased binucleation, elevated cell death, and caused dilation of the resting zones of mature growth plates. Single-cell RNA-seq analyses revealed alterations of transcriptome in all three zones (i.e., resting, proliferative, and hypertrophic zones) of the growth plates. Our results demonstrate a crucial role of α-parvin in long bone development and shed light on the cellular mechanism through which α-parvin regulates the longitudinal growth of long bones.

软骨内骨化需要适当控制软骨细胞增殖、分化、存活和组织。在这里，我们发现从小鼠四肢敲除α-parvin（一种整合素相关的粘着斑蛋白）会导致软骨内骨化和侏儒症缺陷。突变体的长骨更短但更宽，生长板变得杂乱无章，尤其是在增殖区。通过骨外植体培养的双光子延时成像，我们提供了直接证据，表明 α-parvin 调节软骨细胞旋转，这是软骨细胞形成柱状结构所必需的过程。此外，α-parvin 的损失增加了双核，增加了细胞死亡，并导致成熟生长板的静止区扩张。单细胞 RNA-seq 分析揭示了生长板所有三个区域（即静止区、增殖区和肥大区）转录组的变化。我们的结果证明了 α-parvin 在长骨发育中的关键作用，并揭示了 α-parvin 调节长骨纵向生长的细胞机制。