title: Eye defects in receptor protein-tyrosine phosphatase alpha knock-down zebrafish.
abstract: Receptor protein-tyrosine phosphatase alpha (RPTP alpha) is highly expressed in the developing retina of different species, but little is known about its function there. Here, we report that injection of antisense morpholinos in zebrafish embryos reduced RPTP alpha expression to almost nondetectable levels up to 3 days postfertilization (dpf). RPTP alpha was detectable again from 4 dpf onward. RPTP alpha knock-down resulted in smaller eyes. Examination of sections of the retina at different developmental stages demonstrated that already at 28 hours postfertilization (hpf) fewer cells were present in the retina of RPTP alpha-morpholino-injected embryos. At 3 dpf, the layered organization of the retina was absent. In addition, the morphology and labeling with an axon specific antibody, acetylated tubulin, demonstrated that most cells appeared to be undifferentiated. Strikingly, at 5 dpf the lamination of the retina was partially restored, concomitant with re-expression of RPTP alpha protein. Although cells in the retina were now differentiated, the layering of the retina remained disrupted and significant gaps were observed in the amacrine cell layer. Therefore, knock-down of RPTP alpha protein provides evidence that RPTP alpha is essential for normal retinal development.
authors.affiliation: Hubrecht Laboratory, Netherlands Institute for Developmental Biology, Utrecht, The Netherlands.
authors.forename: Astrid M
authors.initials: AM
authors.lastname: van der Sar
authors.forename: Danica
authors.initials: D
authors.lastname: Zivković
authors.forename: Jeroen
authors.initials: J
authors.lastname: den Hertog
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle; D002454:Cell Differentiation; D004625:Embryo, Nonmammalian / Q000201:enzymology / Q000648:ultrastructure; D005124:Eye Abnormalities / Q000196:embryology* / Q000201:enzymology; D005136:Eye Proteins / Q000235:genetics / Q000502:physiology*; D018390:Gene Targeting; D007395:Interneurons / Q000473:pathology; D020319:Oligodeoxyribonucleotides, Antisense / Q000494:pharmacology; D010641:Phenotype; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D017027:Protein Tyrosine Phosphatases / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D054630:Receptor-Like Protein Tyrosine Phosphatases, Class 4; D011956:Receptors, Cell Surface; D012160:Retina / Q000196:embryology* / Q000201:enzymology / Q000473:pathology; D012165:Retinal Ganglion Cells / Q000473:pathology; D017948:Retinal Rod Photoreceptor Cells / Q000473:pathology; D015027:Zebrafish / Q000196:embryology* / Q000378:metabolism; D029961:Zebrafish Proteins / Q000235:genetics / Q000502:physiology*
chemical_list: D005136:Eye Proteins; D020319:Oligodeoxyribonucleotides, Antisense; D011956:Receptors, Cell Surface; D029961:Zebrafish Proteins; D017027:Protein Tyrosine Phosphatases; D054630:Receptor-Like Protein Tyrosine Phosphatases, Class 4; C516847:ptpra protein, zebrafish