Double take

Zebrafish are able to regenerate various organs and tissues after damage or amputation. To understand better the genetic controls of this process, the authors of this study investigated the expression of two genes previously implicated in fin regeneration using semi-quantitative RT-PCR, at three time points after fin amputation (T1, T2, and T3 in Fig. 1, corresponding to the initiation, middle, and end of fin regeneration, respectively). Briefly, the RT-PCR procedure involved isolating messenger RNA (mRNA) from a matched amount of zebrafish cells from the site of fin regeneration at the three time points, and using primers specific to each gene to selectively detect mRNA as an indicator of gene expression levels. The authors used total genomic DNA isolated from zebrafish cells as a positive control, and no RNA or DNA template as a negative control. They found that Gene 1 was only expressed early on in the process, while Gene 2 expression gradually increased during fin regeneration, reaching a peak of expression toward the end of the process. This provides some detailed information that could be useful in elucidating the function of these genes in fin regeneration.