Summary
Two mutations in the gene, RpII215, were analyzed to determine their effects on cell differentiation and proliferation. The mutations differ in that one, RpII215 ts(ts), only displays a conditional recessive lethality, while the other, RpII215 Ubl (Ubl), is a recessive lethal mutation that also displays a dominant mutant phenotype similar to that caused by the mutation Ultrabithorax (Ubx). Ubl causes a partial transformation of the haltere into a wing; however, this transformation is more complete in flies carrying both Ubl and Ubx. The present study shows that patches of Ubl/- tissue in gynandromorphs are morphologically normal. Cuticle that has lost the wild-type copy of the RpII215 locus fails to show a haltere to wing transformation, nor does it show the synergistic enhancement of Ubx by Ubl. We conclude that an interaction between the two RpII215 alleles, Ubl and RpII215 +, is responsible for the mutant phenotype. Gynandromorphs carrying the ts allele, when raised at permissive temperature, display larger patches of ts/- cuticle than expected, possibly indicating that the proliferation of ts/+ cells is reduced. This might result from an antagonistic interaction between different RpII215 alleles. Classical negative complementation does not appear to be the cause of the antagonistic interaction described above, as only one RpII215 subunit is thought to be present in an active multimeric polymerase enzyme. We have therefore coined the term ‘negative heterosis’ to describe the aforementioned interactions.
We also observed that the effects of mutationally altered RNA polymerase II on somatic cells are different from its effects on germ cells. Mutant somatic cells (either Ubl/- or ts/-, the latter shifted to restrictive temperature) reduce cell proliferation, but otherwise do not appear to disrupt cell differentiation. However, mutant germ cells often differentiate into morphologically abnormal oocytes.
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References
akam M, Moore H, Cox A (1984) Ultrabithorax mutations map to distinct sites within the bithorax complex of Drosophila. Nature 309:635–637
Amati P, Blasi F, Diporzio U, Riccio A, Traboni C (1975) Hamster α-amanitine-resistant RNA polymerase II able to transcribe polyoma virus genome in somatic cell hybrids. Proc Natl Acad Sci USA 72:753–757
Arking R (1975) Temperature-sensitive cell-lethal mutants of Drosophila: Isolation and characterization. Genetics 80:519–537
Artavanis-Tsakonas S, Muskavitch MAT Yedvobnick B (1983) Molecular cloning of Notch a locus affecting neurogenesis in Drosophila melanogaster. Proc Natl Acad Sci USA 80:1977–1981
Bender W, Akam M, Karch F, Beachy PA, Peifer M, Spierer P, Lewis EB, Hogness DS (1983) Molecular genetics of the bithorax complex in Drosophila melanogaster. Science 221:23–29
Bryant RE, Adelberg EA, Magee PT (1977) Properties of an altered RNA polymerase II activity from an α-amanitin-resistant mouse cell line. Biochemistry 16:4237–4244
Catcheside DG, Lea DE (1945) Dominant lethals and chromosome breaks in ring-X chromosomes of Drosophila melanogaster. J Genet 47:25–40
Chambon P (1975) Eukaryotic nuclear RNA polymerase. Annu Rev Biochem 44:613–638
Chan VL, Whitmore GF, Siminovitch L (1972) Mammalian cells with altered forms of RNA polymerase II. Proc Natl Acad SCi USA 69:3119–3123
Cochet-Meilhac M, Chambon P (1974) Animal DNA-dependent RNA polymerases. II. Mechanism of the inhibition of RNA polymerases B by amatoxins. Biochim Biophys Acta 353:160–184
Garcia-Bellido A (1972) Some parameters of mitotic recombination in Drosophila melanogaster. Mol Gen Genet 115:54–72
Greenleaf AL, Borsett LM, Jiamachello PF, Coulter DE (1979) α-amanitin-resistant D. melanogaster with an altered RNA polymerase II. Cell 18:613–622
Greenleaf AL, Weeks JR, Voelker RA, Ohnishi S, Dickson B (1980) Genetic and biochemical characterization of mutants at an RNA polymerase II locus in D. melanogaster. Cell 21:785–792
Greenleaf AL (1983) Amanitin-resistant RNA polymerase II mutations are in the enzyme's largest subunit. J Biol Chem 258:13403–13406
Guialis A, Beatty BG, Ingles CJ, Crerar MM (1977) Regulation of RNA polymerase II activity in α-amanitin-resistant CHO hybrid cells. Cell 10:53–60
Guialis A, Morrison KE, Ingles CJ (1979) Regulated synthesis of RNA polymerase II polypeptides in Chinese hamster ovary cell line. J Biol Chem 254:4171–4176
Kramer A, Bautz EKF (1981) Immunological relatedness of subunits of RNA polymerase II from insects and mammals. Eur J Biochem 117:449–455
Lobban PE, Siminovitch L, Ingles CJ (1976) The RNA polymerase II of an α-amanitin-resistant chinese hamster ovary cell line. Cell 8:65–70
Morata G, Ripoll P (1975) Minutes: Mutants of Drosophila autonomously affecting cell division rate. Dev Biol 42:211–221
Mortin MA, Lefevre Jr G (1981) An RNA polymerase II mutation in Drosophila melanogaster that mimics Ultrabithorax. Chromosoma 82:237–247
Mortin MA, Kaufman TC (1982) Developmental genetics of a temperature-sensitive RNA polymerase II mutation in Drosophila melanogaster. Mol Gen Genet 187:120–125
Mortin MA, Kaufman TC (1984) Developmental effects of a temperature-sensitive RNA polymerase II mutation in Drosophila melanogaster. Dev Biol 103:343–354
Mortin MA (1983) Analysis of a temperature-sensitive mutation in a gene encoding a subunit of RNA polymerase II in Drosophila. Ph.D dissertation Indiana University
Perrimon N, Gans M (1983) Clonal analysis of the tissue specificity of recessive female sterile mutations of Drosophila melanogaster using a dominant female sterile mutation Fs(1)K1237. Dev Biol 100:365–373
Polya GM (1973) Transcription. In: Stewart PR, Letham DS (eds) The Ribonucleic Acids. Springer-Verlag, New York, pp 7–58
Roeder RG (1976) Eukaryotic nuclear RNA polymerases. In: Losick R, Chamberlin M (eds) RNA Polymerase. Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, pp 285–329
Scott MP, Weiner AJ, Hazelrigg TI, Polisky BA, Pirrotta V, Scalenghe F, Kaufman TC (1983) The molecular organization of the Antennapedia locus of Drosophila. Cell 35:763–776
Simpson P, Schneiderman HA (1975) Isolation of temperature sensitive mutations blocking clone development in Drosophila melanogaster, and the effects of a temperature sensitive cell lethal mutation on pattern formation of imaginal discs. Wilhelm Roux Arch 178:247–275
Simpson P (1976) Analysis of the compartments of the wing of Drosophila melanogaster mosaic for a temperature-sensitive mutation that reduces mitotic rate. Dev Biol 54:100–115
Somers DG, Pearson ML, Ingles CJ (1975) Regulation of RNA polymerase II activity in a mutant rat myoblast cell line resistant to α-amanitin. Nature 253:372–374
Turner FR, Mahowald AP (1976) Scanning electron microscopy of Drosophila melanogaster embryogenesis. I. The structure of the egg envelope and the formation of the cellular blastoderm. Dev Biol 50:95–108
Vaisius AC, Wieland T (1982) Formation of a single phosphodiester bond by RNA polymerase B from calf thymus is not inhibited by α-amanitin. Biochemistry 21:3097–3101
Windsor B, Lacroute F, Ruet A, Sentenac A (1979) Isolation and characterisation of a strain of Saccharomyces cerevisiae deficient in in vitro polymerase B(II) activity. Mol Gen Genet 173:145–151
Young RA, Davis RW (1983) Yeast RNA polymerase II genes: Isolation with antibody probes. Science 222:778–782
Yura T, Ishihama A (1979) Genetics of Bacterial RNA polymerases. Annu Rev Genet 13:59–97
Zalokar M, Erk I, Santamaria P (1980) Distribution of ring-X chromosomes in the blastoderm of gynandromorphic D. melanogaster. Cell 19:133–141
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Communicated by M.M. Green
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Mortin, M.A., Perrimon, N. & Bonner, J.J. Clonal analysis of two mutations in the large subunit of RNA polymerase II of Drosophila . Mol Gen Genet 199, 421–426 (1985). https://doi.org/10.1007/BF00330753
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DOI: https://doi.org/10.1007/BF00330753