Tremblay P, Dietrich S, Mericskay M, Schubert F R, Li Z, Paulin D
Department of Neurology, University of California in San Francisco, San Francisco, California, 94143-0518, USA.
Dev Biol. 1998 Nov 1;203(1):49-61. doi: 10.1006/dbio.1998.9041.
Activated by dorsalizing and lateralizing signals, the Pax3 gene is an early marker for the entire paraxial mesoderm and its dorsal derivative, the dermomyotome. Later, its expression becomes restricted to the lateral dermomyotome and to the migratory muscle precursors giving rise to the hypaxial musculature. To understand better the role that Pax3 plays during development of paraxial mesoderm-derived structures, we followed the development of the musculature and skeleton in the murine Pax3 mutant Splotch. We found that the mutant dermomyotomes and myotomes failed to organize and to elongate medially and laterally, leading to the reduction and malformation of the entire trunk musculature. Mutants lacked ventral aspects of the body wall musculature and muscles derived from migratory myoblasts, suggesting a crucial function for Pax3 in the long-range migration of muscle precursors giving rise to the ventral hypaxial musculature. In addition, severe malformations were detected in the skeleton. The axial and appendicular skeleton displayed malformations and in particular multiple bone fusions.
Pax3基因由背侧化和外侧化信号激活，是整个轴旁中胚层及其背侧衍生物生皮节的早期标志物。后来，其表达局限于外侧生皮节和迁移的肌肉前体细胞，这些细胞产生轴下肌肉组织。为了更好地理解Pax3在轴旁中胚层衍生结构发育过程中的作用，我们追踪了小鼠Pax3突变体Splotch中肌肉组织和骨骼的发育情况。我们发现，突变体的生皮节和肌节无法在内侧和外侧进行组织和伸长，导致整个躯干肌肉组织减少和畸形。突变体缺乏体壁肌肉组织的腹侧部分以及源自迁移成肌细胞的肌肉，这表明Pax3在产生腹侧轴下肌肉组织的肌肉前体细胞的长距离迁移中具有关键作用。此外，在骨骼中检测到严重畸形。轴骨和附肢骨骼出现畸形，特别是多处骨融合。
