Lamprey as Laboratory Model for Study of Molecular Bases of Ontogenesis and Evolutionary History of Vertebrata.

The basic knowledge about the development and formation of the body plan of vertebrates (Vertebrata) was obtained while working with traditional and generally accepted model objects, such as the embryos of mice (Muridae), chickens (Gallus), bony fish (Teleostei), clawed frogs (Xenopus). At the same time, for understanding the evolutionary history of vertebrates, studies of so-called "non-model" objects are of particular value. These animals represent important phylogenetic branches on the evolutionary tree of vertebrates, but do not possess a set of qualities that make them convenient for laboratory work. First of all, such objects include the most ancient living representatives of the taxa, basally diverged from the common evolutionary trunk. These are cyclostomes (Cyclostomata) in the case of vertebrates in general, cartilaginous fish (Chondrichthyes) in the case of gnathostomes (Gnathostomata) and bone ganoids (Holostei) as representatives of new-finned fish (Neopterygii). The research value of these ancient groups lies in the fact that morphological features that are later characteristic of the entire taxon appear in their evolution for the first time, for example, the telencephalon and neural crest cells in cyclostomes, paired fins and the jaws in cartilaginous fish. Representatives of these groups provide an opportunity to study the evolutionary premieres of individual structures and features and mechanisms that ensured their emergence. This article presents an overview of studies of whole-genome duplications at the early stages of vertebrate evolution and the emergence of a unique forebrain region, the telencephalon, which we studied on lampreys, as the most ancient representatives of vertebrates available for laboratory research today. [ABSTRACT FROM AUTHOR]