Strict bivalent formation in allotetraploids. Chromosomes of synthetic Arabidopsis suecica at meiotic metaphase I stage were hybridized with species-specific centromeric repeats of Arabidopsis thaliana (red) and Arabidopsis arenosa (green) and show pairing exclusively between homologous chromosomes of the respective genomes. Scale bar, 5 μm.
Pecinka et al. BMC Biology 2011 9:24 doi:10.1186/1741-7007-9-24