摘要
一、绪言Spemann[1]曾将蝾螈胚的躯干诱导者(晚期原口背唇)移植至宿主(早原肠胚)的预定头区诱导出头部结构。庄孝僡[2]利用新鲜的成体蝾螈肝和小鼠肾组织作为诱导物,移植至蝾螈原肠胚的不同平面区域(头区、心区、前躯干区和后躯干区)的腹侧面,并与离体外胚层诱导的外植实验进行对照比较,发现脑、眼、鼻等头部结构的出现率沿宿主的头尾轴方向递减,而前肾、肌肉等躯干结构则逐渐增加。
As an extension of previous investigation,the competence of the epiblast was sudied in further detail,with special reference to the regional response of the chick blastoderm to inductor.Transplantation of Hensen’s node grafts were performed according to the methods described previously.The host blastoderms were removed and fixed at various intervals from 19--40 hours after operation.They were then stained with diluted Dela-field hematoxylin,cleared and examined as whole mounts.Most of the specimens were sectioned in series at 8μfor further observations.Of a total of 134 operated specimens,46 showed an induction of secondary struc-tures from the host blastoderms,in various degrees of regional differentiation 37,pro-duced placodal thickenings and the remaining 51 had no response in the blastoderms.It was observed that secondary structures with regional differentiation were induced exclusively in the epiblast of host blastoderms of stages 5 and 6.The responsiveness of the epiblast decreased rapidly in older blastoderms.The latter either produced only placodal thickenings(stage 7--8)or no response(stage 8--9)to inductive stimu-lus.Our experiments demonstrated that the pattern of the induced structures was deter-mined by a regionally different responsiveness of the epiblast of the host blastoderms,accompanied by the process of aging,rather than the specific actions of the inductors.The evidence was that when a head organizer(node graft of stage 4)was transplanted to the host blastoderm,the secondary head structure was induced exclusively in the head region of the host,and of the secondary trunk-tail structure appeared in the trunk region.In other words,the prospective head epiblast of host blastoderms responsed to the in-ductor by forming a brain structure,whereas the prospective trunk epiblast,responsed to the same inductor(head organizer)by forming a spinal cord.Further evidence was found in some instances that the induced trunk-tail structure was often provided with part of hind brain when the inductors were tra
作者
宁爱兰
宗书东
薛社普
NING I-LAN;TSUNG SHU-DUNG;SHIEH SHER-PU(Department of Experimental Morphology,Institute of Experimental Medicine,Academia Medica Sinica)
出处
《解剖学报》
CAS
1965年第3期324-331,共8页
Acta Anatomica Sinica
