title: Life-cycle-generation-specific developmental processes are modified in the immediate upright mutant of the brown alga Ectocarpus siliculosus.
abstract: Development of the sporophyte and gametophyte generations of the brown alga E. siliculosus involves two different patterns of early development, which begin with either a symmetric or an asymmetric division of the initial cell, respectively. A mutant, immediate upright (imm), was isolated that exhibited several characteristics typical of the gametophyte during the early development of the sporophyte generation. Genetic analyses showed that imm is a recessive, single-locus Mendelian factor and analysis of gene expression in this mutant indicated that the regulation of a number of life-cycle-regulated genes is specifically modified in imm mutant sporophytes. Thus, IMM appears to be a regulatory locus that controls part of the sporophyte-specific developmental programme, the mutant exhibiting partial homeotic conversion of the sporophyte into the gametophyte, a phenomenon that has not been described previously.
authors.affiliation: UPMC Université Paris 06, The Marine Plants and Biomolecules Laboratory, UMR 7139, Station Biologique de Roscoff, Place Georges Teissier, BP74, 29682 Roscoff Cedex, France.
authors.forename: Akira F
authors.initials: AF
authors.lastname: Peters
authors.forename: Delphine
authors.initials: D
authors.lastname: Scornet
authors.forename: Morgane
authors.initials: M
authors.lastname: Ratin
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Charrier
authors.forename: Annabelle
authors.initials: A
authors.lastname: Monnier
authors.forename: Yves
authors.initials: Y
authors.lastname: Merrien
authors.forename: Erwan
authors.initials: E
authors.lastname: Corre
authors.forename: Susana M
authors.initials: SM
authors.lastname: Coelho
authors.forename: J Mark
authors.initials: JM
authors.lastname: Cock
mesh_terms: D000483:Alleles; D003433:Crosses, Genetic; D018507:Gene Expression Regulation, Developmental; D005808:Genes, Recessive; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D000459:Phaeophyceae / Q000166:cytology / Q000235:genetics* / Q000254:growth & development* / Q000528:radiation effects; D010641:Phenotype; D018462:Photobiology; D016133:Polymerase Chain Reaction