title: A monoclonal antibody as a tool to study the subcommissural organ and Reissner's fibre of the sea lamprey: an immunofluorescence study before and after a spinal cord transection.
abstract: Lampreys are vertebrate animal models in spinal cord regeneration studies. In order to gain knowledge on the mechanisms that provide to the lamprey spinal cord its capacity of regeneration we decided to compare the expression patterns of the growth-associated protein 43 (GAP-43) in the CNS of the sea lamprey before and after a complete spinal transection by immunocytochemical methods using an anti-GAP-43 antibody. Surprisingly, in the brain/spinal cord of both normal and injured animals, anti-GAP-43-like labeling was only observed in the subcommissural organ (SCO) and Reissner's fibre (RF). In injured larvae, a dotted labeling was also observed in the meninges and in the blood the vessels of the neighbouring tissues at the site of lesion. The experiments in injured animals showed that after complete spinal cord transection the SCO seems to continue to produce the Reissner's substance (RS), which is accumulated at the proximal site of spinal transection. The dotted labeling observed in the neighbouring tissues could correspond to RS that was released from the site of injury. In Western blot experiments done using protein extracts of the lamprey brain, the anti-GAP-43 antibody did not recognize any protein band of the expected GAP-43 molecular weight, indicating that the secreted material is not this protein. An anti-serotonin antibody was also used as a marker of some brain structures. Serotonergic afferent fibres innervated the SCO. Here we show a new tool that can be used as a highly specific marker in further studies of the SCO/RF system of lampreys.
authors.affiliation: Department of Cell Biology and Ecology, Faculty of Biology, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors.forename: Antón
authors.initials: A
authors.lastname: Barreiro-Iglesias
authors.forename: Verona
authors.initials: V
authors.lastname: Villar-Cerviño
authors.forename: Ramón
authors.initials: R
authors.lastname: Anadón
authors.forename: María Celina
authors.initials: MC
authors.lastname: Rodicio
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D001921:Brain / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D019922:GAP-43 Protein / Q000096:biosynthesis / Q000276:immunology; D006023:Glycoproteins / Q000378:metabolism*; D007814:Larva; D008578:Meninges / Q000378:metabolism; D048428:Petromyzon; D012038:Regeneration; D012701:Serotonin / Q000276:immunology / Q000378:metabolism; D013116:Spinal Cord / Q000378:metabolism / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000378:metabolism; D013351:Subcommissural Organ / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D019922:GAP-43 Protein; D006023:Glycoproteins; D012701:Serotonin