title: IMP-L3, A 20-hydroxyecdysone-responsive gene encodes Drosophila lactate dehydrogenase: structural characterization and developmental studies.
abstract: IMP-L3, a gene isolated as a potential mediator of imaginal disc morphogenesis in Drosophila melanogaster, encodes lactate dehydrogenase (LDH). The predicted amino acid sequence of IMP-L3 is 58-61% identical to those of human LDHs. In cultured imaginal discs, IMP-L3 transcript levels and LDH enzyme activity increase in response to the steroid hormone, 20-hydroxyecdysone. In embryos, IMP-L3 transcript and LDH activity appear in developing somatic muscles by late stage 13, well before the onset of muscular contraction. High levels of transcript and LDH activity persist throughout embryogenesis and throughout larval development. The gene has been localized by in situ hybridization and deficiency mapping to 65A7-65B2 on the third chromosome. LDH activity is reduced to approximately 50% of wild type in animals heterozygous for a deficiency that removes the 65A-B region. Embryos deficient for the 65A-b region lack LDH activity. We conclude that IMP-L3 is the only gene that encodes LDH in Drosophila.
authors.affiliation: Graduate Group in Endocrinology, University of California, Berkeley 94720, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Abu-Shumays
authors.forename: J W
authors.initials: JW
authors.lastname: Fristrom
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D004331:Drosophila melanogaster / Q000196:embryology / Q000201:enzymology / Q000235:genetics*; D004441:Ecdysterone / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D005804:Genes, Lethal; D006801:Humans; D017403:In Situ Hybridization; D019476:Insect Proteins / Q000096:biosynthesis / Q000235:genetics*; D007770:L-Lactate Dehydrogenase / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014158:Transcription, Genetic
chemical_list: D019476:Insect Proteins; D004441:Ecdysterone; D007770:L-Lactate Dehydrogenase