Genome and cell size variation across algal taxa

This review addresses the more than 104-fold variation in genome size (1C DNA) among eukaryotic algae (and making comparisons, where relevant, to embryophytes) in the context of the demonstrated relationship between genome size and cell volume (excluding vacuoles) for diploid organisms. Larger cells per 1C occur genotypically in polyploids, and phenotypically by endoploidy and the occurrence of more than one nucleus per cell. This phenotypic variation in 1C DNA underlies the 1012-fold range in cell size within the life cycle of a species of marine ulvophycean green algae. After describing the range of 1C values within higher taxa of eukaryotic algae, the ways in which the cell nuclear DNA content influences the growth rate of unicellular and multicellular algae is analysed With brief mention of embryophytes, some aspects of nuclear function as a function of genome and cell size are considered, including nuclear gene copy number in relation of the degree to which genes are expressed, and the large distance (1 mm or more) that products of transcription and/or translation have to travel for uninucleate large algal cells.