RRC ID 77427
Author Kawaguchi YW, Tsuchikane Y, Tanaka K, Taji T, Suzuki Y, Toyoda A, Ito M, Watano Y, Nishiyama T, Sekimoto H, Tsuchimatsu T.
Title Extensive Copy Number Variation Explains Genome Size Variation in the Unicellular Zygnematophycean Alga, Closterium peracerosum-strigosum-littorale Complex.
Journal Genome Biol Evol
Abstract 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.) complex, based on short-read sequencing analysis of 22 natural strains and F1 segregation analysis. Six de novo assembled genomes revealed that genome size variation is largely attributable to genome-wide copy number variation (CNV) among strains rather than mating type-linked genomic regions or specific repeat sequences such as rDNA. Notably, about 30% of genes showed CNV even between strains that can mate with each other. Transcriptome and gene ontology analysis demonstrated that CNV is distributed nonrandomly in terms of gene functions, such that CNV was more often observed in the gene set with stage-specific expression. Furthermore, in about 30% of these genes with CNV, the expression level does not increase proportionally with the gene copy number, suggesting presence of dosage compensation, which was overrepresented in genes involved in basic biological functions, such as translation. Nonrandom patterns in gene duplications and corresponding expression changes in terms of gene functions may contribute to maintaining the high level of CNV associated with extensive genome size variation in the C. psl. complex, despite its possible detrimental effects.
Volume 15(8)
Published 2023-8-1
DOI 10.1093/gbe/evad115
PII 7205242
PMID 37348049
PMC PMC10407611
MeSH Closterium* / genetics DNA Copy Number Variations Genome Size Plants / genetics Reproduction / genetics
IF 3.462
Algae NIES-53 NIES-54 NIES-58 NIES-59 NIES-62 NIES-63 NIES-64 NIES-65 NIES-68 NIES-261 NIES-2666 NIES-4319 NIES-4320 NIES-4321