PT  - JOURNAL ARTICLE
AU  - Claus-Peter Stelzer
AU  - Maria Pichler
AU  - Peter Stadler
AU  - Anita Hatheuer
AU  - Simone Riss
TI  - Within-population genome size variation is mediated by multiple genomic elements that segregate independently during meiosis
AID  - 10.1101/623470
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 623470
4099  - http://biorxiv.org/content/early/2019/04/30/623470.short
4100  - http://biorxiv.org/content/early/2019/04/30/623470.full
AB  - Within-species variation in genome size has been documented in many animals and plants. Despite its importance for understanding eukaryotic genome diversity, there is only sparse knowledge about the maintenance and evolution of such variation on a population level. Here we study a natural population of the rotifer Brachionus asplanchnoidis whose members differ up to 1.9-fold in genome size, but were still able to interbreed and produce viable offspring. We show that genome size is highly heritable and can be artificially selected up or down, but not beyond a minimum diploid genome size. Analyses of segregation patterns in haploid males reveal that large genomic elements (multiple Mega-Base pairs in size) provide the substrate of genome size variation. These elements explain the short-term evolutionary dynamics of genome size as well as unexpected patterns, like increased genome size variation among inbred lines. Overall, our study explains how intraspecific genome size variation can be maintained in populations and provides a framework for understanding the evolutionary forces that drive changes in genome size on a population level.