Quantitative analysis of gene expression in longfinned zebrafish.

Abstract

For years, researchers have studied how organ and appendage sizes are tightly regulated to produce species-characteristic proportions. The Schleier zebrafish is a mutant zebrafish that is characterized by elongated fins that make it a valuable target for research on regulation of size and proportion. In addition, this altered fin mutant is valuable to study because it not only shows allometric growth, but it also shows regenerative growth, providing a rich understanding of how the two processes are interrelated. One way to investigate the molecular underpinnings of the mutant Schleier phenotype is to look at which genes are expressed in Schleier caudal fin versus those in wildtype caudal fin. In this study, the expression of four genes (dual oxidase, thioredoxin, hmox1a, coagulation factor 5) related to stress response and oxidoreductase activity, and two genes related to regeneration (fgf20 and msxb) was analyzed by quantitative PCR (qPCR) to verify preliminary RNA-seq data and determine a possible pathway involved in the mutant phenotype. Analysis of the qPCR data shows upregulation of genes related to oxidative stress in the Schleier mutant, but no differential expression of the regeneration markers between the Schleier and wildtype zebrafish. This supports the idea that the longfinned mutant phenotype is not due to the prolonged expression of regeneration genes, but to some other mechanism, such as the triggering of genes related to oxidative stress.