BIOCHEMICAL CHARACTERISTICS OF A DIFFUSIBLE FACTOR THAT INDUCES GAMETOPHYTE TO SPOROPHYTE SWITCHING IN THE BROWN ALGA ECTOCARPUS
Résumé
The haploid-diploid life cycle of the filamentous brown alga Ectocarpus involves alternation between two independent and morphologically distinct multicellular generations, the sporophyte and the gametophyte. Deployment of the sporophyte developmental program requires two TALE homeodomain transcription factors OUROBOROS and SAMSARA. In addition, the sporophyte generation has been shown to secrete a diffusible factor that can induce uni-spores to switch from the gametophyte to the sporophyte developmental program. Here, we determine optimal conditions for production, storage and detection of this diffusible factor and show that it is a heat-resistant, high molecular weight molecule. Based on a combined approach involving proteomic analysis of sporophyte-conditioned medium and the use of biochemical tools to characterize arabinogalactan proteins, we present evidence that sporophyte-conditioned medium contains AGP epitopes and suggest that the diffusible factor may belong to this family of glycoproteins.
Mots clés
arabinogalactan protein
diffusible factor
Ectocarpus
gametophyte
life cycle
sporophyte ACN
acetonitrile
AGP
LC-MS/MS
liquid chromatography coupled to mass spectrometry
ORO
OUROBOROS
PES
Provasoli-enriched natural seawater
SAM
SAMSARA
SCM
sporophyte-conditioned medium
SDS-PAGE
sodium dodecyl sulfatepolyacrylamide gel electrophoresis
TALE HD TF
three amino acid loop extension homeodomain transcription factor
TFA
trifluoroacetic acid
WSC
wall sensing component
Domaines
Sciences du Vivant [q-bio]
Origine : Fichiers produits par l'(les) auteur(s)