Genetic evidence for shared mechanisms of epimorphic regeneration in zebrafish

Abstract

In a microarray-based gene profiling analysis of Mü ller glia-derived retinal stem cells in light-damaged retinas from adult zebrafish, we found that 2 genes required for regeneration of fin and heart tissues in zebrafish, hspd1 (heat shock 60-kDa protein 1) and mps1 (monopolar spindle 1), were up-regulated. Expression of both genes in the neurogenic Mü ller glia and progenitors was independently verified by quantitative reverse transcriptase PCR and in situ hybridization. Functional analysis of temperature-sensitive mutants of hspd1 and mps1 revealed that both are necessary for Mü ller glia-based cone photoreceptor regeneration in adult zebrafish retina. In the amputated fin, hspd1 is required for the induction of mesenchymal stem cells and blastema formation, whereas mps1 is required at a later step for rapid cell proliferation and outgrowth. This temporal sequence of hspd1 and mps1 function is conserved in the regenerating retina. Comparison of gene expression profiles from regenerating zebrafish retina, caudal fin, and heart muscle revealed additional candidate genes potentially implicated in injury-induced epimorphic regeneration in diverse zebrafish tissues.T he study of regeneration has long fascinated biologists and has lately experienced a renaissance associated with growing interest in regenerative medicine and the therapeutic potential of stem cells. Zebrafish (Danio rerio) are an ideal genetic model for studying regeneration in vertebrates (1) because they have remarkable capabilities to regenerate fins (2), heart muscle (3), and nervous tissues (4-7) following injury. A forward mutagenesis screen for temperature-sensitive mutations that interfere with regeneration of amputated caudal fin identified several genes whose functions are critical for specific steps in fin regeneration, including mps1 (monopolar spindle 1, also called ttk, a kinase required for mitotic checkpoint regulation), hspd1 (heat shock 60-kDa protein 1, a mitochondrial chaperone), and fgf20 (fibroblast growth factor 20) (8-10). In addition, gene profiling analysis of regenerating tissues has provided lists of candidate genes associated with regeneration in fin (11), heart (12), and neural retina (13-15).The regeneration of retinal neurons in adult zebrafish is an especially powerful model for studying regeneration of neuronal tissues; laminar retinal architecture and visual function are restored following damage inflicted by surgical lesions, neurotoxins, and laser or photic lesions of retina (16). The neural stem cells in the retina arise from differentiated Müller glia, which respond to local retinal injuries by dedifferentiation, proliferation, and production of multipotent neuronal progenitors (retinal stem cells) that can regenerate all types of retinal neurons (17-19). To discover genes expressed in injury-activated neurogenic Müller glial cells that activate stem cell properties and trigger a neurogenic program, we generated transcriptional profiles of isolated fluorescent-tagged Müller glial cells from light-lesioned adult ...

Tissue regeneration after injury in adult zebrafish: The regenerative potential of the caudal fin

“…Increase of msxb expression is required for tissue outgrowth during regeneration (Thummel et al, 2010). Genetic control of organ regeneration has been reported in other zebrafish organs, such as heart, spinal cord, and retina (Curado et al, 2007;Schoenebeck et al, 2007;Qin et al, 2009;Jopling et al, 2010;Montgomery et al, 2010).…”

“…While amphibians have long been the central characters employed in studies on tissue or organ regeneration (Brockes, 1997;Beck et al, 2009;Contreras et al, 2009;Kragl et al, 2009;Calve et al, 2010), the zebrafish (Danio rerio) have recently emerged as a new vertebrate model for genetic studies of tissue/ organ regeneration. Like amphibians, zebrafish exhibit an enhanced capability of regenerating adult tissues, which include retina, spinal cord, kidney, heart, and fin (Poss et al, 2000a(Poss et al, ,b, 2002aNechiporuk and Keating, 2002;Nechiporuk et al, 2003;Jazwinska et al, 2007;Schoenebeck et al, 2007;Tsai et al, 2007;Qin et al, 2009;Jopling et al, 2010;Thummel et al, 2010). Fin regeneration is a particularly efficient model for studying tissue regeneration.…”

Effects of copper oxide nanoparticles on developing zebrafish embryos and larvae

“…28 For photoreceptors in the outer nuclear layer, the Zpr1 antibody labels a cell surface epitope on red/green-sensitive double cones and the Zpr3 antibody labels an antigenic region on the rods. [29][30][31] At 72 hpf, the ganglion cell layer, inner nuclear layer, and outer nuclear layer were fully laminated. Meanwhile, ganglion cells, cones, and rods were well-differentiated in the retinas of the unexposed group (Figure 5A-C).…”

Regeneration of the adult zebrafish brain from neurogenic radial glia-type progenitors

“…Dedifferentiation is thought to occur, for example, during regeneration of the teleost retina by Müller glia cells that share several morphological and molecular properties with RG Bernardos et al, 2007;Ganz et al, 2010;Hitchcock and Raymond, 2004;Qin et al, 2009;Stenkamp, 2007;Thummel et al, 2008), but also in axolotl limb regeneration (Kragl et al, 2009) and during zebrafish bone regeneration (Knopf et al, 2011). For adult RG, the answer probably requires a more rigorous understanding of dedifferentiation.…”