title: Cell proliferation in the forebrain and midbrain of the sea lamprey.
abstract: Cell proliferation in the forebrain and midbrain of the sea lamprey (Petromyzon marinus L.) was investigated by proliferation cell nuclear antigen (PCNA) immunocytochemistry, with BrdU labeling as a complementary technique. Correspondence between proliferation regions and areas of early neuronal differentiation was also assessed using antibodies against HNK-1 early differentiation marker. The brain of late embryos shows a homogeneously thick ventricular zone (VZ) containing PCNA-immunoreactive (PCNA-ir) nuclei. In early prolarvae, several discontinuities formed by PCNA-negative cells, and differences among regions in VZ thickness, become apparent. In late prolarvae and early larvae, these differences in VZ thickness and appearance, as well as the presence of PCNA-negative discontinuities, allowed us to correlate proliferation domains and neuroanatomical regions. In larvae, the number of PCNA-ir cells in the VZs diminish gradually, although a few PCNA-ir cells are present in the ependyma of most regions. In late larvae, proliferation becomes confined to a few ventricular areas (medial pallium, caudal habenula, ventral preoptic recess near the optic nerve, and tuberal portion of the posterior hypothalamic recess). During metamorphosis there appears to be no proliferation, but in upstream adults a few PCNA-ir cells are observed in the most caudal habenula. The characteristics of the proliferative regions revealed in lamprey with PCNA immunocytochemistry show notable differences from those observed in other vertebrates, and these differences may be related to the peculiar life cycle 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: Begoña
authors.initials: B
authors.lastname: Villar-Cheda
authors.forename: Emma
authors.initials: E
authors.lastname: Pérez-Costas
authors.forename: Miguel
authors.initials: M
authors.lastname: Meléndez-Ferro
authors.forename: Xesús Manoel
authors.initials: XM
authors.lastname: Abalo
authors.forename: Rolando
authors.initials: R
authors.lastname: Rodríguez-Muñoz
authors.forename: Ramón
authors.initials: R
authors.lastname: Anadón
authors.forename: María Celina
authors.initials: MC
authors.lastname: Rodicio
mesh_terms: D000818:Animals; D000963:Antimetabolites / Q000378:metabolism; D001973:Bromodeoxyuridine / Q000378:metabolism; D018959:CD57 Antigens / Q000378:metabolism; D049109:Cell Proliferation; D004027:Diencephalon / Q000033:anatomy & histology; D004625:Embryo, Nonmammalian / Q000033:anatomy & histology; D007798:Lampreys / Q000033:anatomy & histology* / Q000502:physiology; D007814:Larva / Q000033:anatomy & histology / Q000502:physiology; D008636:Mesencephalon / Q000166:cytology* / Q000502:physiology; D008675:Metamorphosis, Biological; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D016548:Prosencephalon / Q000166:cytology* / Q000502:physiology; D013687:Telencephalon / Q000033:anatomy & histology
chemical_list: D000963:Antimetabolites; D018959:CD57 Antigens; D018809:Proliferating Cell Nuclear Antigen; D001973:Bromodeoxyuridine