Genetics of latent zebrafish melanoblasts

描述(由申请人提供)：成熟组织的生长、修复或维持通常需要从干细胞前体细胞中招募新细胞。在斑马鱼中，当干细胞在胚胎中被消融时，或在截肢后再生的鳍中，黑素细胞可以重新建立。我们的目标是了解在胚胎中建立干细胞的机制的细胞和分子基础，或者干细胞如何调查它们的环境，然后被招募来取代再生组织中缺失的细胞。因此，我们将研究生长因子受体、试剂盒或其他候选基因和突变在幼虫中招募黑素细胞干细胞和再生FINS中的作用，或者不同的信号转导途径如何影响黑素细胞迁移或存活的不同细胞功能。具体地说，我们将：(1)通过靶向的吗啉失活或致敏KIT突变的显性增强剂，确定特定于黑素细胞迁移或存活的KIT依赖的信号转导途径。(2)确定KIT在建立或招募黑素细胞干细胞中的作用，这些干细胞在幼虫黑素细胞激光消融后产生新的黑素细胞。(3)订购KIT(一种假定的干细胞标志物)和Trp2(一种假定的黑素母细胞标志物)在再生黑素母细胞谱系的第一次细胞分裂中的表达。(4)评估Pyewacket突变是否影响第一次再生细胞分裂后干细胞和黑素母细胞命运的分配。这项工作将对理解生长因子受体如何通过多条途径发出信号影响多种细胞功能，以及如何招募潜在干细胞来填补细胞缺陷具有普遍影响。这项工作还将对理解黑素细胞发育的基本生物学产生具体影响，这将为深入了解人类色素沉着障碍、黑色素瘤或其他癌症中出现的生长控制机制提供洞察。

DESCRIPTION (provided by applicant): Growth, repair or maintenance of mature tissues often requires recruitment of new cells from stem cell precursors. In zebrafish, melanocytes are re-established from stem cells when ablated in the embryo, or in regenerating fins following amputation. Our goal is to understand the cellular andmolecular basis of mechanisms that establish stem cells in the embryo, or how stem cells survey their environment, and then are recruited to replace missing cells in regenerating tissues. Accordingly, we will study the role of a growth factor receptor, kit, or other candidate genes and mutations, in recruiting melanocyte stem cells in larvae and in regenerating fins, or how different signal transduction pathways affect different cellular functions of melanocyte migration or survival. Specifically, we will:(1) identify kit-dependent signal transduction pathways specific to melanocyte migration or survival, by targeted morpholino-inactivation or dominant enhancers of a sensitized kit mutation.(2) Determine the role of kit in establishing or recruiting melanocyte stem cells that make new melanocytes following larval melanocyte laser ablations, and identify mutations that prevent melanocyte recovery.(3) Order kit (a presumptive stem cell marker) and trp2 (a presumptive melanoblast marker) expression with respect to the first cell division in regeneration melanoblast lineage.(4) Assess whether pyewacket mutation affects the allocation between stem cell and melanoblast fates following the first regeneration cell division.This work will have a general impact on understanding how growth factor receptors signal through multiple pathways to affect multiple cellular functions and how latent stem cells are recruited to fill cellular deficits. This work will also have specific impact on understanding the basic biology of melanocyte development that will provide insight into the growth control mechanisms gone awry in human pigmentation disorders, melanoma or other cancers.