Globins and hemogenic cells in the marine Annelid Platynereis dumerilii shed new light on blood evolution in Bilaterians

Solène Song (1, 2) , Viktor Starunov (3) , Xavier Bailly (4) , Christine Ruta (5) , Pierre Kerner (1) , Annemiek J M Cornelissen (2) , Guillaume Balavoine (1)

1 IJM (UMR_7592) - Institut Jacques Monod
2 MSC - Matière et Systèmes Complexes
3 SPBU - Saint Petersburg State University
4 UMR LSTM - Laboratoire des symbioses tropicales et méditerranéennes
5 UFRJ - Universidade Federal do Rio de Janeiro [Brasil] = Federal University of Rio de Janeiro [Brazil] = Université fédérale de Rio de Janeiro [Brésil]

How vascular systems and their respiratory pigments evolved is still debated. To unravel blood evolution in Bilaterians, we studied the marine Annelid Platynereis dumerilii. Platynereis exhibits a closed vascular system filled with extracellular hemoglobin. An exhaustive screen in Platynereis genome reveals a family of 17 globins. Seven extracellular globins are produced by specialized hemogenic cells lining the vessels of the segmental appendages of the worm, serving as gills. Extracellular globins are absent in juveniles then accumulate considerably as the worm size and activity increase, culminating in swarming adults. Phylogenetic analyses with deep screenings in complete genomes establish that five globin genes (stem globins) were present in the last common ancestor of Bilaterians. All known Bilaterian blood globins are derived convergently from a single presumably ubiquitously expressed, intracellular stem globin gene. All five globin types are retained in Platynereis, reinforcing this species status as a key slow evolving genome within Bilaterians.

Domaines: Sciences du Vivant [q-bio]; Génétique des populations [q-bio.PE]; Embryologie et organogenèse

Solène Song, Viktor Starunov, Xavier Bailly, Christine Ruta, Pierre Kerner, et al.. Globins and hemogenic cells in the marine Annelid Platynereis dumerilii shed new light on blood evolution in Bilaterians. 2019. ⟨hal-03456385v1⟩