Heterochrony of the Expression of Lanf and Foxg1 in the Lamprey Confirms the Appearance of the Telencephalon as an Evolu
- PDF / 1,273,595 Bytes
- 9 Pages / 612 x 792 pts (letter) Page_size
- 120 Downloads / 127 Views
OGY OF ANIMAL DEVELOPMENT (INVERTEBRATES AND VERTEBRATES)
Heterochrony of the Expression of Lanf and Foxg1 in the Lamprey Confirms the Appearance of the Telencephalon as an Evolutionarily Young Superstructure in the Central Nervous System of Vertebrates G. V. Ermakovaa, A. V. Kucheryavyyb, A. G. Zaraiskya, and A. V. Bayramova, * aShemyakin-Ovchinnikov
Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997 Russia Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, 119071 Russia *e-mail: [email protected]
b
Received October 8, 2019; revised November 25, 2019; accepted November 28, 2019
Abstract—One of the most important evolutionary innovations of vertebrates is a complexly structured telencephalon, which provides higher forms of nervous activity in animals and humans. This work is devoted to the study of the appearance of the telencephalon in the early stages of vertebrate evolution. At the same time, there is reason to believe that lampreys, due to their evolutionary antiquity, could retain some ancient expression patterns of genes that regulate the development of the brain in the very first vertebrates. The study of the features of spatio-temporal expression patterns of key genes that regulate the development of the forebrain in lampreys compared with other vertebrates can help to understand the molecular mechanisms underlying the appearance and evolutionary development of this unique structure of vertebrates. This paper presents the results from analyzing the gene-expression dynamics of Lanf, FoxG1, Otx2, Goosecoid, and HoxB9 in the early stages of development of the European river lamprey Lampetra fluviatilis. It was shown that lamprey genes involved in telencephalon differentiation (Lanf and FoxG1) exhibit heterochrony of expression compared with more evolutionarily advanced representatives of vertebrates. This fact confirms the idea that the telencephalon, being evolutionarily the youngest part of the brain, could appear in vertebrate ancestors as a superstructure in the late stages of their embryonic development. Keywords: Lanf, FoxG1, Otx2, Goosecoid, HoxB9, cyclostomates, lampreys, Lampetra fluviatilis, telencephalon development DOI: 10.1134/S1062360420040049
INTRODUCTION The problems in studying the formation mechanisms of the telencephalon in ontogenesis, as well as the study of factors that could lead to its appearance in evolution, are relevant today in developmental biology. The present work is devoted to emergence of the telencephalon in the evolution of vertebrates in the context of molecular mechanisms that differentiate this part of the central nervous system. The fact that all other types of multicellular animals, including the closest relatives of the lower chordate vertebrates (lancelet and tunicates) do not have structures homologous to the telencephalon, indicates that, apparently, it appeared in evolution only in the ancestors of modern vertebrates. Due to this, the genetic mechanisms underlying this aromorphosis present an important
Data Loading...
