title: The mouse Nkx-1.2 homeobox gene: alternative RNA splicing at canonical and noncanonical splice sites.
abstract: A mouse homeobox gene, Nkx-1.2, (previously termed Sax-1) that is closely related to the Drosophila NK-1/S59 gene was cloned, and genomic DNA and cDNA were sequenced. Nine Nkx-1.2 cDNA clones were found that correspond to three species of Nkx-1.2 mRNA that are formed by alternative splicing at conventional 5' donor and 3' acceptor splice sites; however, seven cDNA clones were found that correspond to three species of Nkx-1.2 mRNA from testes that have novel TG/AC 5' and 3' splice sites. The consensus splice sequences are: 5' donor, CC downward arrowTGGAAG; 3' acceptor, ACTTAC downward arrow. Predicted amino acid sequences suggest that some transcripts may be translated into proteins that lack part or all of the homeodomain. At least three bands of Nkx-1.2 mRNA were found in RNA from the testes. Nkx-1.2 mRNA was shown to be present in postmeiotic germ cells of the testis and in mature spermatozoa. Nkx-1.2 mRNA also was found in regions of the adult cerebral cortex, hippocampus, diencephalon, pons/medulla, and cerebellum. Nkx-1.2 mRNA was found in embryos in highest abundance in 10-day embryos; the mRNA levels decrease during further development. Nkx-1.2 mRNA also was found in discrete zones of the embryonic mesencephalon and myelencephalon.
authors.affiliation: Laboratory of Biochemical Genetics, National Heart, Lung, and Blood Institute, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: A C
authors.initials: AC
authors.lastname: Rovescalli
authors.forename: M
authors.initials: M
authors.lastname: Cinquanta
authors.forename: J
authors.initials: J
authors.lastname: Ferrante
authors.forename: C A
authors.initials: CA
authors.lastname: Kozak
authors.forename: M
authors.initials: M
authors.lastname: Nirenberg
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000473:pathology; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D018076:DNA, Complementary; D005260:Female; D015870:Gene Expression; D018398:Homeodomain Proteins / Q000235:genetics*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D012333:RNA, Messenger; D017386:Sequence Homology, Amino Acid; D013094:Spermatozoa; D014157:Transcription Factors
chemical_list: D018076:DNA, Complementary; D018398:Homeodomain Proteins; C109095:Nkx1-2 protein, mouse; D009687:Nuclear Proteins; D012333:RNA, Messenger; D014157:Transcription Factors