Functional analysis of homeobox genes in neuromere development : Mouse molecular genetical approch

(1)体节是轴下肌肉组织的来源，包括肢体、舌头和躯干的骨骼肌。为了解小鼠Lbxl同源框基因在早期体节中胚层分化中的作用，进行了原位杂交分析。在4-6体节期（8dpc），Lbxl首先在上皮体节的侧部和皮肌节上皮中表达。这与myf-5在体节内侧区域的表达相反。Lbxl在体细胞中胚层的横向表达则是沿着体轴的前后方向。后来在10 dpc（第1阶段的肢芽发育）Lbxl阳性迁移细胞起源于外侧dermomyotomal唇在枕骨，前肢和hindlinib水平。他们还表达了Pax-3和c-met，这两种细胞被称为迁移肢体肌肉前体细胞的标志物。在第4阶段后肢芽（11.5dpc），背肌和腹肌前体群体表达Lbxl。第8期前肢芽（ ...更多信息 12.5 dpc），Lbxl表达在近端肌肉块中减少，在近端肌肉块中检测到伴随肌肉分化的肌细胞生成素的高表达。这些结果表明，小鼠Lbxl可能参与的承诺或决定的肌细胞亚群在轴下肌肉组织的发展。(2)分离小鼠Hox 11 L2的鸡对应物cHox 11 L2。cHox 11 L2在鸡外周神经系统中表达，即在鸡外周神经系统中表达。e.基板外胚层起源的感觉颅神经、交感神经节、背根神经节和肠神经节以及脊髓的有限群体。在神经嵴的神经元衍生物中，dHox 11 L2在迁移后细胞中表达，而不在迁移的神经嵴细胞中表达。在10天胚胎的脊髓和背根中也检测到cHox 11 L2 mRNA的强信号。这些结果表明，cHox 11 L2可能在鸡神经系统发育过程中的神经元分化的决定和/或维持中发挥作用。少

(1) Somites are the source of hypaxial musculature including skeletal muscles of the limb, tongue and the trunk. To get insight into the function of mouse Lbxl homeobox gene in the early somitic mesoderni differentiation, in situhybridization analyses was performed. At 4-6 somite stage (8dpc), Lbxl was first expressed in the lateral portion of the epithelial somite and of dermomyotomal epithelium. This was contrast to the expression of myf-5 in the medial region of the somite. Then the lateral expression of Lbxl in somitic mesoderm occurred regionally along the anterior-posterior body axis. Later at 10 dpc (stage 1 for limb bud development) Lbxl-positive migrating cells originated from the lateral dermomyotomal lips at occipital, forelimb and hindlinib levels. They also expressed Pax-3 and c-met known as markers of the migrating limb muscle precursor cells. In stage 4 hindlimb bud (11.5 dpc), the dorsal and ventral muscle precursor populations expressed Lbxl. In stage 8 forelimb buds ( … More 12.5 dpc), Lbxl expression was reduced in the proximal muscle masses where the highly expression of myogenin accompanying the muscle differentiation was detected. These results suggest that mouse Lbxl might be involved in the commitment or determination of a muscle cell subpopulation during the hypaxial musculature development.(2) cHox11L2, the chick counterpart of mouse Hox11L2, was isolated. cHox11L2 was expressed in the developing chick peripheral nervous system, i. e. sensory cranial nerves of the placodal ectoderm origin, sympathetic ganglia, dorsal root ganglia and enteric ganglia as well as the limited population of the spinal cord. In neuronal derivatives of the neural crest, dHox11L2 was expressed in the postmigratory cells and not in the migrating neural crest cells. Furthermore, Intense signals of cHox11L2 mRNA were detected even in the spinal cord and the dorsal root of 10 day embryo. These results suggest that cHox11L2 might play a role in the determination and/or maintenance of neuronal differentiation during chick nervous system development. Less