Haemoglobin was ‘invented’ by one gene, says research

Paris (France): During a replacement study scientists have shown that while haemoglobin appeared independently in several species, it actually descends from one gene transmitted to all or any by their last common ancestor.

The research which was conducted by scientists from CNRS, Universite de Paris and Sorbonne Universite, in association with others at the University of Saint Petersburg and therefore the University of Rio de Janeiro, have shown that while haemoglobin appeared independently in several species, it actually descends from one gene transmitted to all or any by their last common ancestor. These findings were published in BMC Evolutionary Biology.

Having red blood isn’t peculiar to humans or mammals. this color comes from haemoglobin, a posh protein specialized in transporting the oxygen found within the cardiovascular system of vertebrates, but also in annelids (a family whose most famous members are earthworms), molluscs (especially pond snails) and crustaceans (such as daphnia or ‘water fleas’). it had been thought that for haemoglobin to possess appeared in such diverse species, it must are ‘invented’ several times during evolution. But recent research has shown that each one of those haemoglobins born ‘independently’ actually derive from one ancestral gene.

Researchers from the Institut Monod (CNRS/Universite de Paris), the Laboratoire Matiere et Systemes Complexes (CNRS/Universite de Paris), the Station Biologique de Roscoff (CNRS/Sorbonne Universite), the schools of Saint Petersburg (Russia) and Rio de Janeiro (Brazil), conducted this research on Platynereis dumerilii, alittle marine worm with red blood.

It is considered to be an animal that evolved slowly, because its genetic characteristics are on the brink of those of the marine ancestor of most animals, Urbilateria. Studying these worms by comparing them with other species with red blood has helped in tracing back to the origins of haemoglobins.

The research focused on the broad family to which haemoglobins belong: globins, proteins present in most living beings that ‘store’ gases like oxygen and gas . But globins usually act inside the cells because they are doing not circulate within the blood like haemoglobin.

This work shows that altogether species with red blood, it’s an equivalent gene that creates a globin called ‘cytoglobin’ that independently evolved to become a haemoglobin-encoding gene. This new circulating molecule made oxygen transport more efficient in their ancestors, who became larger and more active.

Scientists now want to vary scale and continue this work by studying when and the way the various specialized cells of bilaterian vascular systems emerged.

Urbilateria is that the last common ancestor of bilaterians, i.e. animals with bilateral (left-right) symmetry and sophisticated organs, aside from species with an easier organization like sponges and jellyfish.