title: Fxyd3 and Lgi4 expression in the adult mouse: a case of endogenous antisense expression.
abstract: We have investigated the expression of Fxyd3 and Lgi4 in the adult mouse by Northern blot analyses and in situ hybridization. Murine Fxyd3 and Lgi4 have been mapped to the same locus on mouse Chromosome (Chr) 7, where the last exon of Fxyd3 completely overlaps with the 3'UTR in the last exon of Lgi4, which is transcribed in the opposite orientation. The Fxyd3 gene (formerly called Mat-8) encodes an 8-kDa transmembrane protein that is upregulated in mammary tumors and can induce a chloride conductance upon RNA injection into Xenopus oocytes. Fxyd3 is a member of the Fxyd family of which several members are tissue-specific regulators of ion channels. Murine Lgi4 is a recently described member of the leucine-rich-repeat gene family Lgi. Northern blot analyses demonstrated a 0.6-kb Fxyd3 transcript with abundant expression in the murine skin, colon, and mammary gland, but low level expression in the brain. In contrast, a 3.2-kb Lgi4 transcript was abundant in brain, with lower level expression in colon. Lgi4 transcription in the skin was detectable only by RT-PCR. A Fxyd3-specific sense cRNA probe hybridized to a transcript in Northern blots of brain and colon RNA that co-migrated with the Lgi4 mRNA. In situ hybridization experiments revealed that both Fxyd3 and Lgi4 were expressed in the same tissue compartments in skin, uterus, intestine, mammary gland, and brain. These results demonstrate that Fxyd3 and Lgi4 transcripts potentially form double-stranded RNA molecules in many cell types in vivo, which may impact on their respective expression.
authors.affiliation: Anatomisches Institut, University of Bonn, Nussallee 10, D-53115 Bonn, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Runkel
authors.forename: Marion
authors.initials: M
authors.lastname: Michels
authors.forename: Thomas
authors.initials: T
authors.lastname: Franz
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D015152:Blotting, Northern; D001921:Brain / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002713:Chlorine / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D017403:In Situ Hybridization; D008321:Mammary Glands, Animal / Q000378:metabolism; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008957:Models, Genetic; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics*; D009419:Nerve Tissue Proteins; D016376:Oligonucleotides, Antisense; D009865:Oocytes / Q000378:metabolism; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics*; D018075:RNA, Complementary / Q000378:metabolism; D012330:RNA, Double-Stranded / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014018:Tissue Distribution; D015854:Up-Regulation; D014981:Xenopus
chemical_list: D020413:3' Untranslated Regions; D018076:DNA, Complementary; C484265:Fxyd3 protein, mouse; C485712:Lgi4 protein, mouse; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D016376:Oligonucleotides, Antisense; D011506:Proteins; D018075:RNA, Complementary; D012330:RNA, Double-Stranded; D012333:RNA, Messenger; D002713:Chlorine