Stocker K M, Carlson B M
Department of Biology, University of Michigan, Ann Arbor 48109.
Am J Anat. 1988 May;182(1):84-95. doi: 10.1002/aja.1001820108.
Previous studies showed that grafting wedges of fresh or cultured anterior quail wing mesoderm into posterior slits in chick wing buds resulted in the formation of supernumerary cartilage in a high percentage of cases. When anterior quail mesoderm, which had been dissociated into single cells and pelleted by centrifugation, was grafted into posterior slits of host chick wing buds, supernumerary rods or nodules of cartilage formed in 74.3% of the cases. Few supernumerary skeletal structures formed following control operations in which pelleted dissociated anterior or posterior mesoderm was grafted into homologous locations in host chick wing buds. When pelleted, dissociated anterior mesoderm was cultured in vitro for 1 or 2 days prior to being implanted in posterior locations, the incidence of supernumerary cartilage formation increased to 95.5% and 93.8%, respectively. The incidence of supernumerary cartilage formation following control orthotopic grafts of cultured mesoderm was 11.8% for 1-day and 31% for 2-day cultured anterior mesoderm; for 1- and 2-day cultured posterior mesoderm, the incidence of supernumerary cartilage formation was 20% and 41.7%, respectively. Longer-term culture resulted in a substantial decrease in the percentage of supernumerary cartilage after anterior to posterior grafts and an increase in the incidence of supernumerary cartilage from control grafts. The results demonstrate that quail anterior wing bud mesodermal cells do not need to maintain constant contact with one another in order to retain the ability to form or stimulate the formation of supernumerary cartilage after being grafted into a posterior location in a host wing bud. This ability is retained when the pelleted dissociated mesoderm is cultured in vitro outside the limb field for at least 1 to 2 days.
先前的研究表明，将新鲜的或培养的鹌鹑前肢翼中胚层楔形组织移植到鸡胚翼芽的后缘裂隙中，在很大比例的情况下会导致额外软骨的形成。当鹌鹑前中胚层被解离成单个细胞并通过离心形成细胞团后移植到宿主鸡胚翼芽的后缘裂隙中时，74.3%的情况下会形成额外的软骨棒或软骨结节。在对照操作中，将解离的前或后中胚层细胞团移植到宿主鸡胚翼芽的同源位置，几乎没有形成额外的骨骼结构。当解离的前中胚层细胞团在体外培养1天或2天后再植入后缘位置时，额外软骨形成的发生率分别增加到95.5%和93.8%。培养1天的前中胚层对照原位移植后额外软骨形成的发生率为11.8%，培养2天的为31%；培养1天和2天的后中胚层，额外软骨形成的发生率分别为20%和41.7%。长期培养导致从前向后移植后额外软骨的百分比大幅下降，而对照移植中额外软骨的发生率增加。结果表明，鹌鹑前肢翼芽中胚层细胞在移植到宿主翼芽的后缘位置后，不需要彼此保持恒定接触就能保留形成或刺激形成额外软骨的能力。当解离的中胚层细胞团在肢体区域外体外培养至少1至2天时，这种能力得以保留。
