Publication details

The widespread crucifer species Cardamine flexuosa is an allotetraploid with a conserved subgenomic structure

Authors

MANDÁKOVÁ Terezie MARHOLD Karol LYSÁK Martin

Year of publication 2014
Type Article in Periodical
Magazine / Source New Phytologist
MU Faculty or unit

Central European Institute of Technology

Citation
Web http://onlinelibrary.wiley.com/doi/10.1111/nph.12567/abstract
Doi http://dx.doi.org/10.1111/nph.12567
Field Genetics and molecular biology
Keywords Brassicaceae; Cardamine flexuosa (Wavy Bittercress); chromosome painting; genome collinearity; GISH (genomic in situ hybridization); intergenome translocation; polyploidy
Attached files
Description The origin of Cardamine flexuosa (Wavy Bittercress) has been a conundrum for more than six decades. Here we identify its parental species, analyse its genome structure in comparison to parental genomes and describe intergenomic structural variations in C. flexuosa. Genomic in situ hybridization (GISH) and comparative chromosome painting (CCP) uncovered the parental genomes and the chromosome composition of C. flexuosa and its presumed diploid progenitors. Cardamine flexuosa is an allotetraploid (2n = 4x = 32), originating from two diploid species, Cardamine amara and Cardamine hirsuta (2n = 2x = 16). The two parental species display almost perfectly conserved chromosomal collinearity for seven out of the eight chromosomes. A 13 Mb pericentric inversion distinguishes chromosome CA1 from CH1. A comparative cytomolecular map was established for C. flexuosa by CCP/GISH. Whereas conserved chromosome collinearity between the C. amara and C. hirsuta subgenomes might have promoted intergenomic rearrangements through homeologous recombination, only one reciprocal translocation between two homeologues has occurred since the origin of C. flexuosa. The genome of C. flexuosa demonstrates that allopolyploids can maintain remarkably stable subgenomes over 104–105 yr throughout a wide distribution range. By contrast, the rRNA genes underwent genome-specific elimination towards a diploid-like number of loci.
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