Light promotes asexual reproduction and mediates transcriptomic changes in Pediastrum duplex.

The green alga Pediastrum duplex forms colonies through asexual reproduction and has a unique life cycle. To elucidate the mechanisms that regulate the asexual reproductive cycle in P. duplex, we analyzed the effects of light on the processes and gene expression involved in each step of the asexual reproductive cycle, revealing light irradiation to be essential for increasing the number of colonies.

Diversity of genome size and chromosome number in homothallic and heterothallic strains of the Closterium peracerosum-strigosum-littorale complex (Desmidiales, Zygnematophyceae, Streptophyta).

The evolutionary transitions of mating systems between outcrossing and self-fertilization are often suggested to associate with the cytological and genomic changes, but the empirical reports are limited in multicellular organisms. Here we used the unicellular zygnematophycean algae, the Closterium peracerosum-strigosum-littorale (C. psl.

Erratum: Expanded male sex-determining region conserved during the evolution of homothallism in the green alga .

[This corrects the article DOI: 10.1016/j.isci.

Expanded male sex-determining region conserved during the evolution of homothallism in the green alga .

Male and female genotypes in heterothallic (self-incompatible) species of haploid organisms, such as algae and bryophytes, are generally determined by male and female sex-determining regions (SDRs) in the sex chromosomes. To resolve the molecular genetic basis for the evolution of homothallic (bisexual and self-compatible) species from a heterothallic ancestor, we compared whole-genome data from Thai and Japanese genotypes within the homothallic green alga . The Thai and Japanese algae harbored expanded ancestral male and female SDRs of ∼1 Mbp each, representing a direct heterothallic ancestor.

Extensive Copy Number Variation Explains Genome Size Variation in the Unicellular Zygnematophycean Alga, Closterium peracerosum-strigosum-littorale Complex.

Genome sizes are known to vary within and among closely related species, but the knowledge about genomic factors contributing to the variation and their impacts on gene functions is limited to only a small number of species. This study identified a more than 2-fold heritable genome size variation among the unicellular Zygnematophycean alga, Closterium peracerosum-strigosum-littorale (C. psl.