MUTATIONS AFFECTING EYE MORPHOLOGY IN THE DEVELOPING ZEBRAFISH (DANIO-RERIO)

The zebrafish (Danio rerio) has received considerable attention as a m ainstream model for the molecular and genetic study of vertebrate deve lopment. In our laboratory, we have conducted a third-generation scree n of chemically mutagenized zebrafish for recessive mutations affectin g the visual system. This report describes the visible phenotypes and number of morphological mutants so far observed and presents a more de tailed histological analysis of six of these mutations. Through analys is of mutant larvae, it was determined that several of the subtle morp hological mutations resulted in degeneration of specific cellular laye rs of he retina. Other mutations resulted in some degeneration distrib uted diffusely across the entire retina or concentrated at the retinal margin. A single mutation affecting invagination of the optic cup and lens vesicle Formation resulted in a failure to develop an anterior c hamber. These results demonstrate the utility of a small-scale, highly focused screen for uncovering novel loci involved in retinal and eye development. (C) 1997 Wiley-Liss, Inc.