ANNELID REGENERATION

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 动物在再生失去的身体部位的能力上有很大的差异。许多刺胞动物（例如，例如，海葵、环节蠕虫和扁形动物都具有惊人的再生能力，能够从原始动物的一小部分再生出一个完整的成年动物。 相反，大多数脊椎动物（哺乳动物、鸟类、爬行动物）和蜕皮动物门（例如，节肢动物、线虫）是相对较差的再生者;尽管能够进行一些有限的再生，但这些生物体中几乎没有一种可以再生其主要身体轴的部分，并且没有一种可以从小片段再生完整的身体。动物之间再生潜力的系统发育分布强烈表明，祖先动物具有广泛的再生能力，再生能力的丧失一直是许多动物谱系的主要进化趋势。 了解再生损失的最终和近因需要详细了解再生和非再生物种的进化力量和发育机制，最好是密切相关的物种。我们已经确定了一组小的，淡水环节动物（分节）蠕虫，naidine oligochaelus，其中包括密切相关的物种，显着不同的能力，他们的头再生。头部再生似乎是祖先的组和non-anteriorly再生物种可能代表至少两个独立的和相对较新的进化损失的再生能力。 因此，Naidines是研究再生能力自然丧失的根本原因的极好系统。 我们目前正在研究再生和非再生物种的一系列发育现象（细胞分裂，程序性细胞死亡，细胞迁移，神经系统动力学，身体模式化）（NSF资助IOB-0520389），以确定正常发生的过程和非再生物种中未能发生的过程。 我们现在渴望将我们的研究扩展到包括生物电事件，如离子电流和电压梯度，这些事件越来越多地被认为与再生潜力密切相关。 我们目前的项目的主要目标是描述膜电压的变化和离子电流在头截肢后的第一个24小时内在至少一个再生物种（我们的主要重点将是普里什蒂纳leidyi，这是特别透明，易于操作），然后调查这些功能在至少一个非再生物种。 我们的期望是，再生和非再生物种将显示显着不同的模式截肢后的电压变化和离子通量。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Animals vary dramatically in their ability to regenerate lost body parts. Many cnidarians (e.g., anemones), annelids (segmented worms), and platyhelminths (flatworms), for example, have fantastic regeneration abilities and are capable of regenerating an entire adult from a small portion of the original animal. In contrast, most amniote vertebrates (mammals, birds, reptiles) and ecdysozoan phyla (e.g., arthropods, nematodes) are relatively poor regenerators; though capable of some limited regeneration, almost none of these organisms can regenerate parts of their primary body axis and none can regenerate a complete body from a small fragment. The phylogenetic distribution of regeneration potential across animals strongly suggests that the ancestral animal had extensive regeneration abilities and that loss of regeneration abilities has been a major evolutionary trend in many animal lineages. Understanding the ultimate and proximate causes of regeneration loss requires a detailed understanding of the evolutionary forces and developmental mechanisms operating in regenerating and non-regenerating species, preferably closely related ones. We have identified a group of small, freshwater annelid (segmented) worms, the naidine oligochaetes, that includes closely related species differing markedly in their ability to regenerate their heads. Head regeneration appears to be ancestral for the group and non-anteriorly regenerating species are likely to represent at least two independent and relatively recent evolutionary losses of regeneration ability. Naidines are therefore an excellent system in which to investigate the underlying causes of natural losses of regeneration ability. We are currently investigating a range of developmental phenomena (cell division, programmed cell death, cell migration, nervous system dynamics, body patterning) across both regenerating and non-regenerating species (NSF grant IOB-0520389) in order to identify processes which occur normally and which fail to occur in non-regenerating species. We are now eager to expand our studies to include bioelectric events, such as ion currents and voltage gradients, which are increasingly being recognized as intimately linked to the potential to regenerate. Our main goal for the current project is to describe membrane voltage changes and ion currents during the first 24 hours following head amputation in at least one regenerating species (our primary focus would be on Pristina leidyi, which is particularly transparent and easy to manipulate) and then to investigate these features in at least one of the non-regenerating species. Our expectation is that regenerating and non-regenerating species will display markedly different patterns of post-amputation voltage changes and ion fluxes.