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中招募新细胞。在斑马鱼中，胚胎中切除的干细胞或截肢后再生的鱼鳍可以重建黑色素细胞。我们的目标是了解干细胞在胚胎中建立机制的细胞和分子基础，或者干细胞如何调查它们的环境，然后在再生组织中被招募来取代缺失的细胞。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和再生鳍中招募黑素细胞干细胞中的作用，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。具体来说，我们将：(1)通过靶向morpholinos失活或敏化kit突变的显性增强子，确定特定于黑素细胞迁移或存活的试剂盒依赖信号转导途径。(2)确定kit在建立或募集黑素细胞干细胞中的作用，该干细胞在幼虫黑素细胞激光消融后产生新的黑素细胞，并确定阻止黑素细胞恢复的突变。(3) Order kit（一种假定的干细胞标记物）和trp2（一种假定的黑色素细胞标记物）在再生黑色素细胞谱系中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成黑素细胞命运的分配。这项工作将对理解生长因子受体如何通过多种途径信号传导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特殊影响，这将为人类色素沉着障碍、黑色素瘤或其他癌症的生长控制机制提供见解。

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.