title: Isolation, X location and activity of the marsupial homologue of SLC16A2, an XIST-flanking gene in eutherian mammals.
abstract: X chromosome inactivation (XCI) achieves dosage compensation between males and females for most X-linked genes in eutherian mammals. It is a whole-chromosome effect under the control of the XIST locus, although some genes escape inactivation. Marsupial XCI differs from the eutherian process, implying fundamental changes in the XCI mechanism during the evolution of the two lineages. There is no direct evidence for the existence of a marsupial XIST homologue. XCI has been studied for only a handful of genes in any marsupial, and none in the model kangaroo Macropus eugenii (the tammar wallaby). We have therefore studied the sequence, location and activity of a gene SLC16A2 (solute carrier, family 16, class A, member 2) that flanks XIST on the human and mouse X chromosomes. A BAC clone containing the marsupial SLC16A2 was mapped to the end of the long arm of the tammar X chromosome and used in RNA FISH experiments to determine whether one or both loci are transcribed in female cells. In male and female cells, only a single signal was found, indicating that the marsupial SLC16A2 gene is silenced on the inactivated X.
authors.affiliation: ARC Centre for Kangaroo Genomics, Research School of Biological Sciences, The Australian National University, Canberra, ACT 0200, Australia. edda.koina@anu.edu.au
authors.forename: Edda
authors.initials: E
authors.lastname: Koina
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Wakefield
authors.forename: Cristina
authors.initials: C
authors.lastname: Walcher
authors.forename: Christine M
authors.initials: CM
authors.lastname: Disteche
authors.forename: Siobhan
authors.initials: S
authors.lastname: Whitehead
authors.forename: Mark
authors.initials: M
authors.lastname: Ross
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Marshall Graves
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D002874:Chromosome Mapping; D002875:Chromosomes; D017124:Conserved Sequence; D003315:Cornea / Q000166:cytology; D004303:Dosage Compensation, Genetic; D004847:Epithelial Cells / Q000166:cytology; D019143:Evolution, Molecular; D005260:Female; D005347:Fibroblasts / Q000166:cytology; D015870:Gene Expression; D020869:Gene Expression Profiling; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D008322:Mammals / Q000235:genetics*; D008394:Marsupialia / Q000235:genetics*; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D027501:Monocarboxylic Acid Transporters / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D027981:Symporters; D014960:X Chromosome
chemical_list: D026901:Membrane Transport Proteins; D027501:Monocarboxylic Acid Transporters; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; C090735:SLC16A2 protein, human; C484257:Slc16a2 protein, mouse; D027981:Symporters; C077885:XIST non-coding RNA