title: Chromatin diminution in the copepod Mesocyclops edax: elimination of both highly repetitive and nonhighly repetitive DNA.
abstract: Chromatin diminution, a developmentally regulated process of DNA elimination, is found in numerous eukaryotic species. In the copepod Mesocyclops edax, some 90% of its genomic DNA is eliminated during the differentiation of embryonic cells into somatic cells. Previous studies have shown that the eliminated DNA contains highly repetitive sequences. Here, we sequenced DNA fragments from pre- and postdiminution cells to determine whether nonhighly repetitive sequences are also eliminated during the process of chromatin diminution. Comparative analyses of these sequences, as well as the sequences eliminated from the genome of the copepod Cyclops kolensis, show that they all share similar abundances of tandem repeats, dispersed repeats, transposable elements, and various coding and noncoding sequences. This suggests that, in the chromatin diminution observed in M. edax, both highly repetitive and nonhighly repetitive sequences are eliminated and that there is no bias in the type of nonhighly repetitive DNA being eliminated.
authors: Département de biologie et Centre de recherche avancée en génomique environnementale, Université d'Ottawa, Ottawa, ON K1N 6N5, Canada.
authors: Christian
authors: C
authors: McKinnon
authors: Guy
authors: G
authors: Drouin
mesh_terms: D000818:Animals; D002843:Chromatin / Q000235:genetics*; D033342:Copepoda / Q000235:genetics*; D004247:DNA / Q000737:chemistry; D004251:DNA Transposable Elements; D019143:Evolution, Molecular; D016678:Genome; D020071:Interspersed Repetitive Sequences; D010802:Phylogeny; D012091:Repetitive Sequences, Nucleic Acid; D017422:Sequence Analysis, DNA; D020080:Tandem Repeat Sequences
chemical_list: D002843:Chromatin; D004251:DNA Transposable Elements; D004247:DNA