CNV in zebrafish genome

Scientists know that zebrafish is a wonderful animal model for developmental studies. However, from the genomic point of view Danio rerio is often a nightmare due to the high level of sequence variation even within zebrafish strains.
It is thus not surprising to read in a recent article on PNAS that the "amount of copy number variation is four times that previously observed in other vertebrates, including humans". The authors of the study come to this conclusion after constructing a genome-wide, high-resolution CNV map comprising 6,080 CNV elements and encompassing 14.6% of the zebrafish reference genome. The analysis has been carried out using 80 zebrafish genomes, representing three commonly used laboratory strains and one native population.