Tracing phylogeny through proteins of the layers of the eye lens nucleus

1. In accordance with the concept that ontogeny recapitulates phylogeny, it was hypothesized that the proteins in the eye lens nucleus increase in antiquity with depth of layer and so can be used to reconstruct the phylogenetic past. 2. This hypothesis was tested by analyzing electrophoretic patterns of proteins from solubilized nuclear lens layers of three tuna species with well-studied phylogenies. The tuna species are the albacore, Thunnus alalunga; yellowfin, T. albacares; and skipjack, Katsuwonus pelamis. 3. The electrophoretic patterns fitted a scheme that is in agreement with major phylogenetic beliefs about these species. Additionally, the patterns seemed to indicate that (a) the skipjack diverged later (although to a lesser degree) from a common ancestor than did the other two tuna species, and (b) the albacore is more closely related to the skipjack than is the yellowfin. 4. It is concluded that electrophoretic analysis of proteins from nuclear lens layers is a promising new tool for tracing phylogenetic relationships.