A chromosomal factor exerting a predetermining effect on morphogenesis in the multicellular green alga Ulva mutabilis

Abstract

SUMMARYA new spontaneous mutant bubble (bu) with a marked effect on early morphogenesis in the multicellular green alga, Ulva mutabilis is described. It behaves as a recessive chromosomal mutant. The bu+ gene product formed in heterozygous sporophytes exerts a predetermining effect on morphogenesis of haploid gametophytes with the bu genotype. It is suggested that the product of the bu+ gene affects the orientation of the mitotic spindles during early development.