Convergent recruitment of TALE homeodomain life cycle regulators to direct sporophyte development in land plants and brown algae

Alok Arun (1) , Susana Coelho (1) , Akira F Peters (2) , Simon Bourdareau (1) , Laurent Pérès (1) , Delphine Scornet (1) , Martina Strittmatter (1) , Agnieszka Lipinska (1) , Haiqin Yao (1) , Olivier Godfroy (1) , Gabriel J Montecinos (1) , Komlan Avia (1) , Nicolas Macaisne (1) , Christelle Troadec (3) , Abdelhafid Bendahmane (3) , J. Mark Cock (1)

1 LBI2M - Laboratoire de Biologie Intégrative des Modèles Marins
2 Bezhin Rosko
3 IPS2 (UMR_9213 / UMR_1403) - Institut des Sciences des Plantes de Paris-Saclay

Three amino acid loop extension homeodomain transcription factors (TALE HD TFs) act as life cycle regulators in green algae and land plants. In mosses these regulators are required for the deployment of the sporophyte developmental program. We demonstrate that mutations in either of two TALE HD TF genes, OUROBOROS or SAMSARA, in the brown alga Ectocarpus result in conversion of the sporophyte generation into a gametophyte. The OUROBOROS and SAMSARA proteins heterodimerise in a similar manner to TALE HD TF life cycle regulators in the green lineage. These observations demonstrate that TALE-HD-TF-based life cycle regulation systems have an extremely ancient origin, and that these systems have been independently recruited to regulate sporophyte developmental programs in at least two different complex multicellular eukaryotic supergroups, Archaeplastida and Chromalveolata.

Domaines: Sciences du Vivant [q-bio]

Alok Arun, Susana Coelho, Akira F Peters, Simon Bourdareau, Laurent Pérès, et al.. Convergent recruitment of TALE homeodomain life cycle regulators to direct sporophyte development in land plants and brown algae. eLife, 2019, 8, ⟨10.7554/eLife.43101⟩. ⟨hal-02042404⟩