Abstract
Flies mutant for one or both of the last two enzymes of de novo pyrimidine biosynthesis express a number of phenotypes that are also expressed by mutants of the first four pathway enzymes (r and Dhod-null mutants). However, r-1 flies also express two phenotypes, mottled eyes and poor viability, that are not usually expressed by r and Dhod-null flies. Chemical determinations show that orotic acid, a substrate for the fifth pathway enzyme, accumulates in r-1 individuals but not in r and wild-type individuals. Moreover, flies simultaneously mutant for r and r-1 do not express the mottled-eye phenotype, showing that r is epistatic to r-1 for this r-1-specific phenotype. When genotypically wild-type flies are cultured on a medium containing 6-azauracil, the base of a potent inhibitor of the last enzyme of de novo pyrimidine biosynthesis, phenocopies are obtained that include the mottled-eye as well as the wing phenotypes of r-1 flies. These results support hypotheses that the phenotypes common to r, Dhod-null, and r-1 flies are consequences of uridylic acid deficiency, whereas the r-1-specific phenotypes result from orotic acid accumulation in flies lacking either or both of the last two enzymes of de novo pyrimidine biosynthesis.
Similar content being viewed by others
References
Brothers, V., Tsubota, S., Germeraad, S., and Fristrom, J. (1978). The rudimentary locus of Drosophila melanogaster: Partial purification of a carbamyl phosphate synthase-aspartate transcarbamylase-dihydroorotase complex. Biochem. Genet. 16321.
Christopherson, R., and Finch, L. (1977). The assay of orotate by an isotope dilution procedure. Anal. Biochem. 80159.
Coleman, P., Suttle, D., and Stark, G. (1977). Purification from hamster cells of a multifunctional protein that initiates de novo synthesis of pyrimidine nucleotides. J. Biol. Chem. 2526379.
Counce, S. (1956). Studies on female-sterility genes in Drosophila melanogaster. III. Effect of the gene rudimentary on embryonic development. Z. Vererbrungsl. 87482.
Handschumacher, R. (1960). Orotidylic acid decarboxylase: Inhibition studies with azauridine 5′-phosphate. J. Biol. Chem. 2352917.
Harris, M., and Oberholzer, V. (1980). Conditions affecting the colorimetry of orotic acid and orotidine in urine. Clin. Chem. 26473.
Jarry, B. (1978). Purification of aspartate transcarbamylase from Drosophila melanogaster. Eur. J. Biochem. 87533.
Jarry, B., and Falk, D. (1974). Functional diversity with the rudimentary locus of Drosophila melanogaster. Mol. Gen. Genet. 135113.
Jones, M. (1980). Pyrimidine nucleotide biosynthesis in animals: Genes, enzymes, and regulation of UMP biosynthesis. Annu. Rev. Biochem. 49253.
Kelley, W., and Smith, L. (1978). Disorders of purine and pyrimidine metabolism. In Stanbury, J., Wyngaarden, J., and Frederickson, D. (eds.), The Metabolic Basis of Inherited Disease 4th ed., McGraw-Hill, New York, pp. 1045–1075.
Lastowski, D., and Falk, D. (1980). Characterization of an autosomal rudimentary-shaped wing mutation in Drosophila melanogaster that affects pyrimidine synthesis. Genetics 96471.
Lewis, E. (1960). A new standard food medium. Dros. Inform. Serv. 34117.
Lindsley, D., and Grell, E. (1968). Genetic Variations of Drosophila melanogaster. Carnegie Inst. Wash. Publ. No. 627.
McClard, R., Black, M., Livingstone, L., and Jones, M. (1980). Isolation and initial characterization of the single polypeptide that synthesizes uridine-5′-monophosphate from orotate in Ehrlich ascites carcinoma. Biochemistry 194699.
Morgan, T. (1912). A modification of the sex ratio and of other ratios in Drosophila through linkage. Z. Verebrungsl. 7323.
Mori, M., and Tatibana, M. (1975). Purification of homogenous glutamine-dependent carbamyl phosphate synthetase from ascites hepatoma cells as a complex with aspartate transcarbamylase and dihydroorotase. J. Biochem. 78239.
Norby, S. (1970). A specific nutritional requirement for pyrimidines in rudimentary mutants of Drosophila melanogaster. Hereditas 66205.
Norby, S. (1973). The biochemical genetics of rudimentary mutants of Drosophila melanogaster. I. Asparate carbamoyltransferase levels in complementing and non-complementing strains. Hereditas 7311.
Rawls, J. (1978). Enzymatic synthesis of [6-14C]orotidine 5′-monophosphate and its use in the assay of orotate phosphoribosyltransferase and orotidylate decarboxylase. Anal. Biochem. 86107.
Rawls, J. (1979). The enzymes for de novo pyrimidine biosynthesis in Drosophila melanogaster: Their localization, properties, and expression during development. Comp. Biochem. Physiol. 62B207.
Rawls, J. (1980). Identification of a small genetic region that encodes orotate phosphoribosyl-transferase and orotidylate decarboxylase in Drosophila melanogaster. Mol. Gen. Genet. 17843.
Rawls, J. (1981). Genetic complementation and enzyme correlates at the locus encoding the last two steps of de novo pyrimidine biosynthesis in Drosophila melanogaster. Mol. Gen. Genet. 184174.
Rawls, J., and Fristrom J. (1975). A complex genetic locus that controls the first three steps of pyrimidine biosynthesis in Drosophila. Nature 255738.
Rawls, J., and Porter, L. (1979). Organization of the rudimentary wing locus in Drosophila melanogaster. I. The isolation and partial characterization of mutants induced with ethylmethanesulfonate, ICR-170, and X-rays. Genetics 93143.
Rizki, R., and Rizki, T. (1965). Morphogenetic effects of 6-azauracil and 6-azauridine. Science 150222.
Stroman, P., Bahn, E., Norb, S., and Sick, K. (1973). 6-Azauracil induced phenocopies of rudimentary wing mutants and their suppression by a suppressor mutant of rudimentary in Drosophila melanogaster. Hereditas 73239.
Tax, W., Veerkamp, J., and Schretlen, E. (1978). The urinary excretion of orotic acid and orotidine, measured by an isotope dilution assay. Clin. Chim. Acta. 90217.
Author information
Authors and Affiliations
Additional information
This research was supported by NSF Research Grant PCM 78-14164, an NSF predoctoral fellowship award to T. Conner, and an NIH research career development award to J. Rawls.
Rights and permissions
About this article
Cite this article
Conner, T.W., Rawls, J.M. Analysis of the phenotypes exhibited by rudimentary-like mutants of Drosophila melanogaster . Biochem Genet 20, 607–619 (1982). https://doi.org/10.1007/BF00483960
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00483960