Development and regeneration of the zebrafish maxillary barbel

描述（由申请人提供）：斑马鱼是一种脊椎动物，可以再生几种成年组织类型。这些结构包括鳍、心脏和眼睛等研究得很充分的结构，但也有研究得很少的结构，比如胡须状的面部胡须。斑马鱼的上颌倒刺（ZMB）包含皮肤细胞、腺体、味蕾、结缔组织、神经和血管成分。因为透明的杠铃是外部的，所以内部所有分化的细胞类型都是可见的，实验上是可以接近的。众所周知，其他种类的鱼类也能再生刺，但斑马鱼的这种能力还没有被研究过。基于迄今为止的研究，我们假设Wnt信号分子和glypican共受体对损伤后ZMB的生长和再生都至关重要。在我们的第一个目标中，我们将记录在这个附属物的发育和再生过程中细胞分裂和细胞死亡的模式，并确认我们是第一个描述的倒钩淋巴的存在和功能。在第二个目标中，我们将1)绘制ZMB组织中非规范Wnt配体和受体（glypicans和zzzzleds）的时空分辨率图，2)使用转基因鱼来测试恢复glypicans功能是否可以恢复斑马鱼突变体ZMB的生长，3)调查ZMB出芽和再生是否需要规范Wnt信号，4)使用morpholino方法测试ZMB中的候选基因。从这些研究中获得的知识将大大有助于我们了解皮肤和皮肤附属物发育和维持中涉及的遗传相互作用。由于ZMB是一种可再生的成人器官，因此本研究还将阐明许多终末分化细胞类型（包括血管、淋巴和神经）对损伤的反应。与斑马鱼尾鳍的再生不同，ZMB的再生以异常细胞增殖和细胞外基质沉积为特征，这一过程可能与脊椎动物伤口愈合病理（如瘢痕疙瘩和/或增生性疤痕）有关。斑马鱼倒刺神经能够将轴突再生到味蕾目标，这可能为恢复创伤组织的外周感觉提供了途径。最后，在ZMB内可用的毛细血管袢和大的、可接近的淋巴系统是一个有吸引力的系统，用于研究脉管系统的生理和病理功能，包括液体平衡和肿瘤转移。

DESCRIPTION (provided by applicant): The zebrafish is a vertebrate animal that can regenerate several adult tissue types. These include well-studied structures such as fins, heart and eyes, but also poorly studied ones, such as the whisker-like facial barbels. The zebrafish maxillary barbel (ZMB) contains skin cells, glands, taste buds, connective tissues, nerves, and vascular components. Because the transparent barbells are external, all of the differentiated cell types within are visible and experimentally accessible. Barbels are known to regenerate in other species of fishes, but have not been studied for this capacity in zebrafish. Based on studies to date, we hypothesize that Wnt signaling molecules and glypican co- receptors are critical for both ZMB outgrowth and regeneration after injury. In our first aim, we will document patterns of cell division and cell death during development and regeneration of this appendage, and confirm the existence and function of the barbel lymphatics, which we are the first to describe. In the second aim, we will 1) map the spatial and temporal resolution of non-canonical Wnt ligands and receptors (glypicans and frizzleds) in ZMB tissue, 2) use transgenic fish to test if restoring glypican function restores ZMB outgrowth in a zebrafish mutant, 3) survey if canonical Wnt signaling is required for ZMB budding and regeneration, and 4) test candidate genes in the ZMB using a morpholino approach. Knowledge gained from these investigations will contribute significantly to our understanding of the genetic interactions involved in the development and maintenance of skin and skin appendages. Because the ZMB is an adult organ that regenerates, this study will also illuminate the response to injury of many terminally differentiated cell types, including blood vessels, lymphatics and nerves. Unlike regeneration in the zebrafish caudal fin, regeneration in the ZMB is characterized by abnormal cell proliferation and extracellular matrix deposition, a process that may be relevant to vertebrate wound healing pathologies such as keloids and/or hypertrophic scars. The ability of zebrafish barbel nerves to regrow axons to their taste bud targets may suggest approaches to restore peripheral sensation to traumatized tissues. Finally, the availability within the ZMB of both a capillary loop and a large, accessible lymphatic is an attractive system in which to study the physiological and pathological functions of the vasculature, including fluid balance and tumor metastasis. )