title: Genomic organization and allelic expression of UBE3A in chicken.
abstract: UBE3A, the gene associated with Angelman syndrome, is part of a cluster of genes in the human chromosome 15q11-q13/mouse chromosome 7C region, that is subject to genomic imprinting. In human and mouse brain, UBE3A is expressed predominantly from the maternal allele, and the paternal allele is silenced. A current model concerning the evolution of genomic imprinting, the parental conflict hypothesis, posits that this epigenetic phenomenon is restricted to eutherian mammals. It has been recently reported, however, that several chicken orthologues of mammalian imprinted loci display DNA replication asynchrony, a property of imprinted genes. A separate group also reported monoallelic expression of chicken IGF2 in developing chicken embryos. These observations could suggest that genomic imprinting may occur in chicken. We have assembled the predicted mRNA consensus sequence for the chicken UBE3A gene using published ESTs. We report a high degree of homology with the human UBE3A at the nucleotide and protein levels, as well as a highly conserved genomic organization. Biallelic expression of UBE3A is observed in embryonic chicken brain and limb, indicating that UBE3A is not subject to genomic imprinting in chicken.
authors.affiliation: Department of Genetics and Developmental Biology, University of Connecticut Health Center, 263 Farmington Ave., Farmington, CT 06032 USA.
authors.forename: Dan C
authors.initials: DC
authors.lastname: Colosi
authors.forename: Danielle
authors.initials: D
authors.lastname: Martin
authors.forename: Karen
authors.initials: K
authors.lastname: Moré
authors.forename: Marc
authors.initials: M
authors.lastname: Lalande
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002642:Chick Embryo; D002645:Chickens / Q000235:genetics*; D016384:Consensus Sequence; D004247:DNA / Q000235:genetics; D020224:Expressed Sequence Tags; D005260:Female; D015870:Gene Expression; D016678:Genome; D018392:Genomic Imprinting; D006801:Humans; D008297:Male; D008957:Models, Genetic; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D044767:Ubiquitin-Protein Ligases / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D004247:DNA; C471639:UBE3A protein, human; D044767:Ubiquitin-Protein Ligases