title: Tissue specific expression of mouse alpha-amylase genes.
abstract: Two distinct alpha-amylase genes, Amy-1a and Amy-2a, are expressed in the mouse strain A/J. Amy-1a and Amy-2a are interrupted by 10 and 9 introns, respectively. With the exception of the first Amy-1a intron, which has no counterpart in Amy-2a, introns are located at analogous positions within the two genes. Comparable exons of Amy-1a and Amy-2a are more highly conserved in sequence than analogous introns. Amy-2a specifies pancreatic alpha-amylase mRNA. Two apparently identical copies of this gene exist in the haploid mouse genome. The single copy of Amy-1a is expressed in a tissue specific fashion in the salivary gland and the liver. It specifies alpha-amylase mRNA with identical translated and 3' nontranslated sequences but different 5' nontranslated sequences in the two tissues. These different mRNAs are generated by tissue specific splicing events. S1 nuclease mapping of nuclear transcripts from salivary gland and liver suggests the presence of at least two promotors of different strength in Amy-1a. A strong promoter appears to be active in the salivary gland exclusively, while a weak promoter is apparently used in both the salivary gland and the liver. The data suggest that regulation of Amy-1a expression occurs primarily at the transcriptional level.
mesh_terms: D000681:Amylases / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D004262:DNA Restriction Enzymes; D005796:Genes; D008099:Liver / Q000201:enzymology; D051379:Mice; D008805:Mice, Inbred A; D009693:Nucleic Acid Hybridization; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D012469:Salivary Glands / Q000201:enzymology; D014158:Transcription, Genetic; D000516:alpha-Amylases / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D004262:DNA Restriction Enzymes; D000681:Amylases; D000516:alpha-Amylases