Javois L C, Frazier-Edwards A M
Department of Biology, Catholic University of America, Washington, DC 20064.
Dev Biol. 1991 Mar;144(1):78-85. doi: 10.1016/0012-1606(91)90480-q.
Previous studies have demonstrated that head activator (HA), an 11 amino acid peptide, stimulates head-specific differentiation processes in hydra. Additionally, HA enhances the differentiation of interstitial cells into nerve cells. This study investigated the effects of exogenous synthetic HA on the dynamics of both apical and basal regeneration in a piece of tissue excised from the body column of treated animals which comprised one-eighth of the original animal. The dynamics of apical and basal regeneration were monitored using the monoclonal antibody TS19. This antibody binds to apical and basal ectodermal tissue very early in the process of regeneration, before morphological structures are evident. Labeling is ultimately localized to the tentacles of the head and a ring above the basal disc. Thus, TS19 is a useful tool for analyzing the dynamics of both apical and basal patterning processes in the same regenerate simultaneously. Quantification of TS19 positive areas on regenerates over a time course of 72 hr revealed that HA treatment accelerated and amplified the dynamics of both apical and basal TS19 labeling. The specific basal effect was novel and was demonstrated to occur in the absence of a determined head independently of new nerve cell differentiation. It is proposed that the basal effect was the result of growth factor-like activity of HA.
先前的研究表明，头部激活因子（HA）是一种由11个氨基酸组成的肽，可刺激水螅头部特异性分化过程。此外，HA还能增强间质细胞向神经细胞的分化。本研究调查了外源性合成HA对从经处理动物体柱切下的、占原动物八分之一的一块组织的顶端和基部再生动力学的影响。使用单克隆抗体TS19监测顶端和基部再生的动力学。在再生过程的早期，在形态结构明显之前，这种抗体就会与顶端和基部外胚层组织结合。标记最终定位于头部的触手和基部盘上方的一个环。因此，TS19是同时分析同一再生体中顶端和基部模式形成过程动力学的有用工具。在72小时的时间进程中对再生体上TS19阳性区域进行定量分析发现，HA处理加速并放大了顶端和基部TS19标记的动力学。特定的基部效应是新发现的，并且被证明在没有确定的头部的情况下独立于新神经细胞分化而发生。有人提出，基部效应是HA的生长因子样活性的结果。
