Hannes Becher1, Robyn F Powell2, Max R Brown1,3, Chris Metherell4, Jaume Pellicer2,5, Ilia J Leitch2, Alex D Twyford1,6. 1. Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Charlotte Auerbach Road, Edinburgh, EH9 3FL, UK. 2. Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, UK. 3. Wellcome Trust Genome Campus, Hinxton, Saffron Walden CB10 1RQ, UK. 4. Botanical Society of Britain and Ireland, 4 High Firs Crescent, Harpenden, Hertfordshire AL5 1NA, UK. 5. Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia sn, 08038, Barcelona, Spain. 6. Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh EH3 5LR, UK.
Abstract
BACKGROUND AND AIMS: Genome size varies considerably across the diversity of plant life. Although genome size is, by definition, affected by genetic presence/absence variants, which are ubiquitous in population sequencing studies, genome size is often treated as an intrinsic property of a species. Here, we studied intra- and interspecific genome size variation in taxonomically complex British eyebrights (Euphrasia, Orobanchaceae). Our aim is to document genome size diversity and investigate underlying evolutionary processes shaping variation between individuals, populations and species. METHODS: We generated genome size data for 192 individuals of diploid and tetraploid Euphrasia and analysed genome size variation in relation to ploidy, taxonomy, population affiliation, and geography. We further compared the genomic repeat content of 30 samples. KEY RESULTS: We found considerable intraspecific genome size variation, and observed isolation-by-distance for genome size in outcrossing diploids. Tetraploid Euphrasia showed contrasting patterns, with genome size increasing with latitude in outcrossing Euphrasia arctica, but with little genome size variation in the highly selfing Euphrasia micrantha. Interspecific differences in genome size and the genomic proportions of repeat sequences were small. CONCLUSIONS: We show the utility of treating genome size as the outcome of polygenic variation. Like other types of genetic variation, such as single nucleotide polymorphisms, genome size variation may be affected by ongoing hybridisation and the extent of population subdivision. In addition to selection on associated traits, genome size is predicted to be affected indirectly by selection due to pleiotropy of the underlying presence/absence variants.
BACKGROUND AND AIMS: Genome size varies considerably across the diversity of plant life. Although genome size is, by definition, affected by genetic presence/absence variants, which are ubiquitous in population sequencing studies, genome size is often treated as an intrinsic property of a species. Here, we studied intra- and interspecific genome size variation in taxonomically complex British eyebrights (Euphrasia, Orobanchaceae). Our aim is to document genome size diversity and investigate underlying evolutionary processes shaping variation between individuals, populations and species. METHODS: We generated genome size data for 192 individuals of diploid and tetraploid Euphrasia and analysed genome size variation in relation to ploidy, taxonomy, population affiliation, and geography. We further compared the genomic repeat content of 30 samples. KEY RESULTS: We found considerable intraspecific genome size variation, and observed isolation-by-distance for genome size in outcrossing diploids. Tetraploid Euphrasia showed contrasting patterns, with genome size increasing with latitude in outcrossing Euphrasia arctica, but with little genome size variation in the highly selfing Euphrasia micrantha. Interspecific differences in genome size and the genomic proportions of repeat sequences were small. CONCLUSIONS: We show the utility of treating genome size as the outcome of polygenic variation. Like other types of genetic variation, such as single nucleotide polymorphisms, genome size variation may be affected by ongoing hybridisation and the extent of population subdivision. In addition to selection on associated traits, genome size is predicted to be affected indirectly by selection due to pleiotropy of the underlying presence/absence variants.
Authors: Phen Garrett; Hannes Becher; Galina Gussarova; Claude W dePamphilis; Rob W Ness; Shyam Gopalakrishnan; Alex D Twyford Journal: Front Plant Sci Date: 2022-05-27 Impact factor: 6.627
Authors: Alexandra V Amosova; Olga Yu Yurkevich; Nadezhda L Bolsheva; Tatiana E Samatadze; Svyatoslav A Zoshchuk; Olga V Muravenko Journal: Genes (Basel) Date: 2022-04-26 Impact factor: 4.141
Authors: Olga V Muravenko; Olga Yu Yurkevich; Julia V Kalnyuk; Tatiana E Samatadze; Svyatoslav A Zoshchuk; Alexandra V Amosova Journal: Plants (Basel) Date: 2022-08-29