caa a22 4500 469082704 CHVBK 20180323132955.0 cr unu---uuuuu 170328e19920201xx s 000 0 eng 10.1007/BF00302976 doi (NATIONALLICENCE)springer-10.1007/BF00302976 Ultrastructural study of the retinal pigment epithelium during metamorphosis in the sea lamprey ( Petromyzon marinus L.) [Elektronische Daten] [Encarnación de Miguel, Hans-Joachim Wagner, Ramón Anadón] Summary: The sequence of morphological changes in the retinal pigment epithelium during the metamorphic period of the sea lamprey Petromyzon marinus L. has been investigated using electron microscopy. At early metamorphic stages (stages I and II), photoreceptors are present in a small zone of the retina. During these stages, the lateral surface of the epithelial cells shows zonulae occludentes and adhaerentes. The degree of cell differentiation varies throughout the retinal pigment epithelium. Cells covering the differentiated photoreceptors in the central retina have phagosomes, whereas pigment granules appear only in the retinal pigment epithelium dorsal to the optic nerve head. Most epithelial cells have myeloid bodies; their morphology is more complex around the optic nerve head. At stage III, when photoreceptors develop over the whole retina, the distribution of cytoplasmic organelles is almost homogeneous in the retinal pigment epithelium. Subsequently, the basal plasma membrane of the epithelial cells becomes progressively folded and their apical processes enlarged. In addition, extensive gap junctions develop between retinal pigment cells. In late metamorphic stages, noticeable growth of myeloid bodies occurs and consequently the retinal pigment epithelium resembles that of the adult. This study also describes, for the first time, the presence of wandering phagocytes in the retinal pigment epithelium of lampreys; their role in melanosome degradation is discussed. Springer-Verlag, 1992 Retinal pigment epithelium nationallicence Ultrastructure nationallicence Organelle differentiation nationallicence Metamorphosis nationallicence Lamprey, Petromyzon marinus (Cyclostomata) nationallicence de Miguel Encarnación Department of Fundamental Biology, University of Santiago, E-15706, Santiago de Compostela, Spain aut Wagner Hans-Joachim Institut für Anatomie und Zellbiologie der Universität, W-3550, Marburg, Germany aut Anadón Ramón Department of Fundamental Biology, University of Santiago, E-15706, Santiago de Compostela, Spain aut Cell and Tissue Research Springer-Verlag 267/2(1992-02-01), 375-384 0302-766X 267:2<375 1992 267 441 https://doi.org/10.1007/BF00302976 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00302976 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- de Miguel Encarnación Department of Fundamental Biology, University of Santiago, E-15706, Santiago de Compostela, Spain aut NATIONALLICENCE 700 1- Wagner Hans-Joachim Institut für Anatomie und Zellbiologie der Universität, W-3550, Marburg, Germany aut NATIONALLICENCE 700 1- Anadón Ramón Department of Fundamental Biology, University of Santiago, E-15706, Santiago de Compostela, Spain aut NATIONALLICENCE 773 0- Cell and Tissue Research Springer-Verlag 267/2(1992-02-01), 375-384 0302-766X 267:2<375 1992 267 441 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer