It was thought that hemoglobin must have been “invented” several times during its evolution in order to appear in such diverse species. However, recent studies have shown that all of these “independently” born hemoglobins are actually derived from a single ancestral gene.
“The study focused on a wide range of families to which hemoglobin belongs: proteins present in almost every organism that” stores “gas such as globin, oxygen and nitric oxide. However, globin does not circulate in the blood like hemoglobin, so it normally acts intracellularly.
Institut Jacques Monod (CNRS / University of Paris), Laboratoire Matire et Systmes Complexes (CNRS / University of Paris), Station Biologique de Roscoff (CNRS / University of Sorbonne), St. Petersburg University (Russia), Rio researcher de Janeiro (Brazil) We conducted this study on Platynereis dumerilii, a small marine worm with red blood.
Its genetic characteristics are similar to those of Urbilateria (1), the marine ancestor of most animals, and are therefore considered to be slowly evolving animals. Studying these worms by comparing them to other species with red blood cells has helped to trace the origin of hemoglobin.
This study shows that in all species with red blood cells, it is the same gene that makes the globin called “cytoglobin,” which evolves independently to become the gene that encodes hemoglobin. This new circulating molecule has made oxygen transport of larger, more active ancestors more efficient.
Scientists now want to continue this study on a scale by studying when and how various specialized cells in the vasculature of bilaterian animals emerged.
(1) Bilateria is the last common ancestor of bilaterians, except for species with simpler tissues such as sponges and jellyfish. In other words, it is an animal that is symmetrical and has complex organs.