Zebrafish their larval stages. In 2011, the British Heart Foundation ran an advertising campaign publicising its intention to study the applicability of this ability to humans, stating that it aimed to raise £50 million in research funding. Zebrafish have also been found to regenerate photoreceptor cells and retinal neurons following injury, which has been shown to be mediated by the dedifferentiation and proliferation of Müller glia. Researchers frequently amputate the dorsal and ventral tail fins and analyze their regrowth to test for mutations. It has been found that histone demethylation occurs at the site of the amputation, switching the zebrafish's cells
Evolution of fish The first tetrapodomorphs, which included the gigantic rhizodonts, had the same general anatomy as the lungfish, who were their closest kin, but they appear not to have left their water habitat until the late Devonian epoch (385 - 359 Ma), with the appearance of tetrapods (four-legged vertebrates). Tetrapods are the only tetrapodomorphs that survived after the Devonian. Lobe-finned fishes continued until towards the end of Paleozoic era, suffering heavy losses during the Permian-Triassic extinction event (251 Ma). Ray-finned fishes, class Actinopterygii, differ from lobe-finned fishes in that their fins consist of webs of skin supported by spines ("rays") made of