Life-cycle-generation-specific developmental processes are modified in the immediate upright mutant of the brown alga Ectocarpus siliculosus.
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.
Peters
Akira F
AF
UPMC Université Paris 06, The Marine Plants and Biomolecules Laboratory, UMR 7139, Station Biologique de Roscoff, Place Georges Teissier, BP74, 29682 Roscoff Cedex, France.
Scornet
Delphine
D
Ratin
Morgane
M
Charrier
Bénédicte
B
Monnier
Annabelle
A
Merrien
Yves
Y
Corre
Erwan
E
Coelho
Susana M
SM
Cock
J Mark
JM
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