Clustering of centromeres precedes bivalent chromosome pairing of polyploid wheats

Sexual reproduction of allopolyploid plants, with genomes from two or more related diploid ancestors, implies the formation of homologous bivalent pairing at the first meiotic division. In polyploid wheats, multivalent associations are corrected before recombination occurs. Recent analysis of chromosome arrangement at the onset of meiosis in tetraploid and hexaploid wheats by Enrique Martinez-Perez and colleagues reveals that centromeres form into seven groups before the initiation of synapsis. These complex structures might be involved in the mechanism for sorting the chromosomes.