Chromatin diminution is the programmed deletion of DNA from presomatic cell or nuclear lineages during development, producing single organisms that contain two different nuclear genomes. Phylogenetically diverse taxa undergo chromatin diminution — some ciliates, nematodes, copepods, and vertebrates. In cyclopoid copepods, chromatin diminution occurs in taxa with massively expanded germline genomes; depending on species, germline genome sizes range from 15 – 75 Gb, 12–74 Gb of which are lost from pre-somatic cell lineages at germline – soma differentiation. This is more than an order of magnitude more sequence than is lost from other taxa. To date, the sequences excised from copepods have not been analyzed using large-scale genomic datasets, and the processes underlying germline genomic gigantism in this clade, as well as the functional significance of chromatin diminution, have remained unknown.
Billions of basepairs of recently expanded, repetitive sequences are eliminated from the somatic genome during copepod developmentBMC Genomics (2014)
Publication DateMarch 11, 2014
Citation InformationSun, C., G.A. Wyngaard, D.B. Walton, H.A. Wichman and R. Lockridge Mueller. Billions of basepairs of recently expanded, repetitive sequences are eliminated from the somatic genome during copepod development. BMC Genomics, 15:186. http://www.biomedcentral.com/1471-2164/15/186