B chromosomes manipulate cell division for survival, and new research identifies key genes, including DCR28, involved in this process in rye.

Supernumerary B chromosomes, unlike standard A chromosomes, are not essential for the normal growth and development of organisms. As of 2024, B chromosomes have been identified in nearly 3,000 species across all eukaryotic phyla. While low numbers of B chromosomes typically have no noticeable selective impact, higher numbers can lead to phenotypic abnormalities and decreased fertility.