定向细胞运动和分裂解释早期肢芽形态发生学

The vertebrate limb bud arises from lateral plate mesoderm and its overlying ectoderm. Despite progress regarding the genetic
requirements for limb development, morphogenetic mechanisms that generate early outgrowth remain relatively undefined. We
show by live imaging and lineage tracing in different vertebrate models that the lateral plate contributes mesoderm to the early
limb bud through directional cell movement. The direction of cell motion, longitudinal cell axes and bias in cell division planes lie
largely parallel to one another along the rostrocaudal (head-tail) axis in lateral plate mesoderm. Transition of these parameters
from a rostrocaudal to a mediolateral (outward from the body wall) orientation accompanies early limb bud outgrowth.
Furthermore, we provide evidence that Wnt5a acts as a chemoattractant in the emerging limb bud where it contributes to the
establishment of cell polarity that is likely to underlie the oriented cell behaviours. 德国LaVision PIV/PLIF粒子成像测速场仪 Imager SX PIV相机 用于粒子成像测速(PIV)的荧光示踪粒子