Genetic analysis of fin formation in the zebrafish, Danio rerio

Abstract

In the zebrafish, Danio rerio, a caudal and pectoral fin fold develop during embryogenesis. At larval stages the caudal fin fold is replaced by four different fins, the unpaired anal, dorsal and tail fins. In addition the paired pelvic fins are formed. We have identified a total of 118 mutations affecting larval fin formation. Mutations in 11 genes lead to abnormal morphology or degeneration of both caudal and pectoral fin folds. Most mutants survive to adulthood and form a surprisingly normal complement of adult fins. Mutations in nine genes result in an increased or reduced size of the pectoral fins. Interestingly, in mutants of one of these genes, dackel (dak), pectoral fin buds form initially, but later the fin epithelium fails to expand. Expression of sonic hedgehog mRNA in the posterior mesenchyme of the pectoral fin bud is initiated in dak embryos, but not maintained. Mutations in five other genes affect adult fin but not larval fin development. Two mutants, longfin (lof) and another longfin (alf) have generally longer fins. Stein und bein (sub) has reduced dorsal and pelvic fins, whereas finless (fls) and wanda (wan) mutants affect all adult fins. Finally, mutations in four genes causing defects in embryonic skin formation will be briefly reported.

Evidence for Organic Film on an Impervious Urban Surface: Characterization and Potential Teratogenic Effects

“…Controls in the 2% DMSO carrier appeared normal (Figure F). We note that the pectoral fins were not strongly affected, which is consistent with evidence for different genetic and epigenetic specification pathways for caudal and pectoral fins ( , ).…”

Developmental independence of median fins from the larval fin fold revises their evolutionary origin

“…This discrepancy in molecular signaling mechanisms between early induction of the LMFF and later outgrowth at the dorsal fin primordium suggest that the developmental modules associated with the dorsal fin primordium are independent of those involved in LMFF formation. Previous studies have shown that some zebrafish mutants with malformed LMFFs, which are bubbly or in which the edge of the fin fold is collapsed, develop normal adult median fins 44 . This evidence supports our inference that the developmental module of the dorsal fins behaves independently from the LMFF developmental module.…”

Latent developmental potential to form limb-like skeletal structures in zebrafish

“…Although large dominant screens are not common in zebrafish, mutants having viable dominant phenotypes have been identified as a by-product of recessive genetic screens. We searched published screens and identified a mutant called wanda (wan) with a phenotype similar to reph (Figure S2) (12,20). We obtained the wan mutant and found that it exhibited intermediate radials in a pattern similar to reph (Fig.…”