The perplexed and confused mutations affect distinct stages during the transition from proliferating to post-mitotic cells within the zebrafish retina. Dev Biol 2001 Aug 15;236(2):436-53
Date
07/31/2001Pubmed ID
11476583DOI
10.1006/dbio.2001.0340Scopus ID
2-s2.0-0035881588 (requires institutional sign-in at Scopus site) 25 CitationsAbstract
To identify and study genes essential for vertebrate retinal development, we are screening zebrafish embryos for mutations that disrupt retinal histogenesis. Key steps in retinogenesis include withdrawal from mitosis by multipotent neuroepithelial cells, specification to particular cell types, migration to the appropriate laminar positions, and molecular and morphological differentiation. In this study, we have identified two recessive mutations that affect the transition of proliferating neuroepithelial cells to postmitotic retinal cells. Both the perplexed and confused mutant phenotypes were initially detectable when the first retinal neuroepithelial cells began to leave the cell cycle. At this time, each mutant retina showed increased cell death and a lack of morphological differentiation. Cell death was found to be apoptotic in both perplexed and confused retinas based on TUNEL analysis and activation of caspase-3. TUNEL-phosphoRb-BrdU colocalization studies indicated that the perplexed mutation caused death in cells transitioning from a proliferative to postmitotic state. For the confused mutation, TUNEL-phosphoRb-BrdU analysis revealed that only a subset of postmitotic cells were induced to activate apoptosis. Mosaic analysis demonstrated that within the retina the perplexed mutation functions noncell-autonomously. Furthermore, whole lens or eye cup transplantations indicated that the retinal defect was intrinsic to the retina. Mosaic analysis with confused embryos showed this mutation acts cell-autonomously. From these studies, we conclude that the perplexed and confused genes are essential at distinct stages during the transition from proliferating to postmitotic cells within the zebrafish retina.
Author List
Link BA, Kainz PM, Ryou T, Dowling JEAuthor
Brian A. Link PhD Professor in the Cell Biology, Neurobiology and Anatomy department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsApoptosis
Bromodeoxyuridine
Caspase Inhibitors
Caspases
Cell Differentiation
Cell Division
Cell Survival
Chimera
Genes, Recessive
Histones
Immunohistochemistry
In Situ Hybridization
In Situ Nick-End Labeling
Lens, Crystalline
Mosaicism
Mutagenesis
Mutation
Phenotype
Phosphorylation
RNA, Messenger
Retina
Stem Cells
Transplants
Zebrafish
