An international research group led by Associate Professor Hisayoshi Nozaki of the University of Tokyo Graduate School of Science announced that he discovered that the key genes in the early stages of the evolution of single cells into multicellular organisms are tumor suppressor genes. bottom.This was clarified by decoding the whole genome of Gonium (scientific name: Gonium pectorale), which is a primitive multicellular organism in the group Volvocales, which is a green alga of multicellular organisms.This study was conducted in collaboration with the National Institute of Genetics, the University of Arizona, the University of Kansas, etc.
Humans are complex multicellular organisms consisting of multiple cells, but in ancient times they were unicellular organisms consisting of one cell, and it is said that they were born by "multicellularization".The conversion from unicellular to multicellular organisms has been speculated to have occurred in various eukaryotes, but the causative genes in their early stages have been a mystery.
This time, the international research group compared and analyzed the whole genome data of gonium with that of single-celled Chlamydomonas and multicellular volvox with advanced cell roles.As a result, it was clarified that the gene that regulates the cell cycle (RB gene) is the cause of multicellularization, which is a tumor suppressor gene of retinoblastoma, which is a malignant tumor in the eyeball in humans. rice field.In addition, it is speculated that the cell cycle regulatory gene cluster will evolve in the early stage of multicellularization, and then the gene cluster that divides the roles of cells will evolve.
In the future, the entire genome information of the earliest multicellular organism, Tetrabaena socialis, and the colonial Volvocales, which have a higher evolutionary stage and are closer to Volvocales, will be revealed, and the evolutionary process from unicellular organisms to complex multicellular organisms will be revealed. It is expected to be elucidated at the genetic level.