title: Chicken orthologues of mammalian imprinted genes are clustered on macrochromosomes and replicate asynchronously.
abstract: In the chicken genome, most orthologues of mouse imprinted genes are clustered on macrochromosomes. Only a few orthologues are located in the microchromosome complement. Macrochromosomal and, to a lesser extent, microchromosomal regions containing imprinted gene orthologues exhibit asynchronous DNA replication. We conclude that highly conserved arrays of imprinted gene orthologues were selected during vertebrate evolution, long before these genes were recruited for parent-specific gene expression by genomic imprinting mechanisms. Evidently, the macrochromosome complement provides a better chromatin environment for the establishment of asynchronous DNA replication and imprinted gene expression later in evolution than microchromosomes.
authors.affiliation: Institute of Human Genetics, Johannes Gutenberg University Mainz, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Dünzinger
authors.forename: Indrajit
authors.initials: I
authors.lastname: Nanda
authors.forename: Michael
authors.initials: M
authors.lastname: Schmid
authors.forename: Thomas
authors.initials: T
authors.lastname: Haaf
authors.forename: Ulrich
authors.initials: U
authors.lastname: Zechner
mesh_terms: D000818:Animals; D002645:Chickens; D002875:Chromosomes; D022202:Chromosomes, Artificial, Bacterial; D004261:DNA Replication; D019143:Evolution, Molecular; D016678:Genome; D018392:Genomic Imprinting; D006801:Humans; D051379:Mice