Cooper, S.Murphy, R.Dolman, G.Hussey, D.Hope, R.2006-07-052006-07-051996Molecular Biology and Evolution (MBE), 1996; 13(7):1012-10220737-40381537-1719http://hdl.handle.net/2440/11481Beta-globin gene families in eutherians (placental mammals) consist of a set of four or more developmentally regulated genes which are closely linked and, in general, arranged in the order 5'-embryonic/fetal genes-adult genes-3'. This cluster of genes is proposed to have arisen by tandem duplication of ancestral beta-globin genes, with the first duplication occurring 200 to 155 MYBP just prior to a period in mammalian evolution when eutherians and marsupials diverged from a common ancestor. In this paper we trace the evolutionary history of the beta-globin gene family back to the origins of these mammals by molecular characterization of the beta-globin gene family of the Australian marsupial Sminthopsis crassicaudata. Using Southern and restriction analysis of total genomic DNA and bacteriophage clones of beta-like globin genes, we provide evidence that just two functional beta-like globin genes exist in this marsupial, including one embryonic-expressed gene (S.c-epsilon) and one adult-expressed gene (S.c-beta), linked in the order 5'-epsilon-beta-3'. The entire DNA sequence of the adult beta-globin gene is reported and shown to be orthologous to the adult beta-globin genes of the North American marsupial Didelphis virginiana and eutherian mammals. These results, together with results from a phylogenetic analysis of mammalian beta-like globin genes, confirm the hypothesis that a two-gene cluster, containing an embryonic- and an adult-expressed beta-like globin gene, existed in the most recent common ancester of marsupials and eutherians. Northern analysis of total RNA isolated from embryos and neonatals indicates that a switch from embryonic to adult gene expression occurs at the time of birth, coinciding with the transfer of the marsupial from a uterus to a pouch environment.en© 1996 Society for Molecular Biology and EvolutionAnimalsMarsupialiaDeoxyribonuclease BamHISite-Specific DNA-Methyltransferase (Adenine-Specific)GlobinsDNA ProbesBlotting, NorthernBlotting, SouthernIn Situ HybridizationRestriction MappingCloning, MolecularAge FactorsEvolution, MolecularPhylogenyGene Expression Regulation, DevelopmentalAmino Acid SequenceBase SequenceMultigene FamilyMolecular Sequence DataAustraliaGenetic VariationGenetic LinkageJournal article0030004281001996558710.1093/oxfordjournals.molbev.a025651A1996VE169000132-s2.0-002983732168287Cooper, S. [0000-0002-7843-8438]Dolman, G. [0000-0001-7611-6841]