Production and Bioassay of a Diffusible Factor That Induces Gametophyte-to-Sporophyte Developmental Reprogramming in the Brown Alga Ectocarpus

Haiqin Yao (1, 2) , Delphine Scornet (1, 2) , Yacine Badis (1) , Akira F Peters (3) , Murielle Jam (1) , Cécile Hervé (1) , Philippe Potin (1) , Susana M Coelho (1, 2) , J. Mark Cock (1, 2)

1 SBR - Station biologique de Roscoff
2 LBI2M - Laboratoire de Biologie Intégrative des Modèles Marins
3 Bezhin Rosko

The brown alga Ectocarpus has a haploid-diploid life cycle that involves alternation between two multicellular generations, the sporophyte and the gametophyte. Life cycle generation is not determined by ploidy but by a genetic system that includes two different three amino acid loop extension homeodomain transcription factors called OUROBOROS and SAMSARA. In addition, sporophytes have been shown to secrete a diffusible factor into the medium that can induce gametophyte initial cells to switch from the gametophyte to the sporophyte developmental program. The protocol presented here describes how to produce sporophyte-conditioned medium containing the diffusible sporophyte-inducing factor and how to assay for activity of the factor using a meio-spore-based bioassay. The protocol, which describes how several steps of these procedures can be optimised, will represent a useful tool for future work aimed at characterising the diffusible factor and investigating its mode of action.

Keywords: Brown algae; Diffusible sporophyte-inducing factor; Ectocarpus; Gamete; Gametophyte; Life cycle; Meio-spore; Sporophyte

Domains: Life Sciences [q-bio]

Haiqin Yao, Delphine Scornet, Yacine Badis, Akira F Peters, Murielle Jam, et al.. Production and Bioassay of a Diffusible Factor That Induces Gametophyte-to-Sporophyte Developmental Reprogramming in the Brown Alga Ectocarpus. Bio-protocol , 2020, 10, ⟨10.21769/bioprotoc.3753⟩. ⟨hal-02995785⟩