Rees Lana, König Désirée, Jaźwińska Anna
Department of Biology, University of Fribourg, Fribourg, Switzerland.
Front Cell Dev Biol. 2023 Feb 9;11:1134451. doi: 10.3389/fcell.2023.1134451. eCollection 2023.
Fin regeneration has been extensively studied in zebrafish, a genetic model organism. Little is known about regulators of this process in distant fish taxa, such as the family, represented by the platyfish. Here, we used this species to investigate the plasticity of ray branching morphogenesis following either straight amputation or excision of ray triplets. This approach revealed that ray branching can be conditionally shifted to a more distal position, suggesting non-autonomous regulation of bone patterning. To gain molecular insights into regeneration of fin-specific dermal skeleton elements, actinotrichia and lepidotrichia, we localized expression of the genes and in the regenerative outgrowth. Blocking of the BMP type-I receptor suppressed phospho-Smad1/5 immunoreactivity, and impaired fin regeneration after blastema formation. The resulting phenotype was characterized by the absence of bone and actinotrichia restoration. In addition, the wound epidermis displayed extensive thickening. This malformation was associated with expanded Tp63 expression from the basal epithelium towards more superficial layers, suggesting abnormal tissue differentiation. Our data add to the increasing evidence for the integrative role of BMP signaling in epidermal and skeletal tissue formation during fin regeneration. This expands our understanding of common mechanisms guiding appendage restoration in diverse clades of teleosts.
鳍再生在斑马鱼（一种遗传模式生物）中已得到广泛研究。对于远缘鱼类类群（如以剑尾鱼为代表的 科）中这一过程的调节因子知之甚少。在这里，我们利用这种物种研究了直切或切除鳍条三联体后鳍条分支形态发生的可塑性。这种方法表明鳍条分支可以有条件地转移到更远端的位置，这表明骨模式形成存在非自主调节。为了从分子层面深入了解鳍特有的真皮骨骼元素（鳍条和鳞条）的再生过程，我们在再生芽基中定位了 基因和 的表达。阻断I型骨形态发生蛋白（BMP）受体可抑制磷酸化Smad1/5免疫反应性，并在芽基形成后损害鳍再生。所产生的表型特征是骨骼和鳍条无法恢复。此外，伤口表皮出现广泛增厚。这种畸形与p63从基底上皮向更表层的表达扩展有关，提示组织分化异常。我们的数据进一步证明了BMP信号在鳍再生过程中对表皮和骨骼组织形成的整合作用。这扩展了我们对硬骨鱼不同类群中指导附肢修复的共同机制的理解。
