Fernández López, BlancaRomaus-Sanjurjo, DanielSenra Martínez, PabloAnadón Álvarez, RamónBarreiro Iglesias, AntónRodicio Rodicio, María Celina2020-05-182020-05-182016Fernández-López, B., Romaus-Sanjurjo, D., Senra-Martínez, P., Anadón, R., Barreiro-Iglesias, A., & Rodicio, M. C. (2016). Spatiotemporal pattern of doublecortin expression in the retina of the sea lamprey. Frontiers in neuroanatomy, 10, 5.http://hdl.handle.net/10347/22373Despite the importance of doublecortin (DCX) for the development of the nervous system, its expression in the retina of most vertebrates is still unknown. The key phylogenetic position of lampreys, together with their complex life cycle, with a long blind larval stage and an active predator adult stage, makes them an interesting model to study retinal development. Here, we studied the spatiotemporal pattern of expression of DCX in the retina of the sea lamprey. In order to characterize the DCX expressing structures, the expression of acetylated α-tubulin (a neuronal marker) and cytokeratins (glial marker) was also analyzed. Tract-tracing methods were used to label ganglion cells. DCX immunoreactivity appeared initially in photoreceptors, ganglion cells and in fibers of the prolarval retina. In larvae smaller than 100 mm, DCX expression was observed in photoreceptors, in cells located in the inner nuclear and inner plexiform layers (IPLs) and in fibers coursing in the nuclear and IPLs, and in the optic nerve (ON). In retinas of premetamorphic and metamorphic larvae, DCX immunoreactivity was also observed in radially oriented cells and fibers and in a layer of cells located in the outer part of the inner neuroblastic layer (INbL) of the lateral retina. Photoreceptors and fibers ending in the outer limitans membrane (OLM) showed DCX expression in adults. Some retinal pigment epithelium cells were also DCX immunoreactive. Immunofluorescence for α-tubulin in premetamorphic larvae showed coexpression in most of the DCX immunoreactive structures. No cells/fibers were found showing DCX and cytokeratins colocalization. The perikaryon of mature ganglion cells is DCX negative. The expression of DCX in sea lamprey retinas suggests that it could play roles in the migration of cells that differentiate in the metamorphosis, in the establishment of connections of ganglion cells and in the development of photoreceptors. Our results also suggest that the radial glia and retinal pigment epithelium cells of lampreys are neurogenic. Comparison of our observations with those reported in gnathostomes reveals similarities and interesting differences probably due to the peculiar development of the sea lamprey retina.engCopyright © 2016 Fernández-López, Romaus-Sanjurjo, Senra-Martínez, Anadón, Barreiro-Iglesias and Rodicio. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution and reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these termshttps://creativecommons.org/licenses/by/4.0/AgnathansDCXAcetylated α-tubulinCytokeratinRetinal developmentMüller cellsRetinal pigment epitheliumjournal article10.3389/fnana.2016.000051662-5129open access