Current Genetics

, Volume 10, Issue 8, pp 593–599 | Cite as

Genetic and molecular characterization of argB+ transformants of Aspergillus nidulans

  • Alan Upshall
Original Articles


Thirty-three argB to argB+ transformants of Aspergillus nidulans have been subjected to genetic and molecular analysis. Two showed high levels of mitotic instability although it is suggested that this is a consequence of heterokaryosis rather than instability of the transformation event. Most transformants resulted from the integration of the transforming DNA in tandem with the chromosomal argB locus. The maximum number of inserted sequences was two, to generate three copies of the argB locus. The other main transformant type showed replacement of the argB mutation by the wild-type allele present on the transforming plasmid. Transformants were also recovered in which the transforming DNA had integrated into non-homologous chromosomal regions. Selfed or hybrid cleistothetica from all transformants, except the gene replacement types gave arginine requiring recombinants. Most transformants showed low levels of meiotic instability. Others displayed varying levels which in some cases differed between selfed and hybrid cleistotheticia. There was some correlation between meiotic instability and the nature of the transformation event. Diploid parasexual and aneuploid analysis located the integrated DNA in each transformant to chromosome III. Two transformants were isolated as heterozygous diploids. A third diploid was isolated as a stable mitotic segregant from one of the mitotically unstable transformants.

Key words

Transformation Aspergillus nidulans Ornithine carbamoyl transferase 


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  1. Ballance DJ, Buxton FP, Turner G (1983) Biochem Biophys Res Commun 112:284–289Google Scholar
  2. Berse B, Dmochowska A, Skrzypek M, Weglenski P, Bates MA, Weiss RJ (1983) Gene 25:109–117Google Scholar
  3. Clutterbuck AJ (1974) In: King RC (ed) Handbook of genetics, vol 1. Plenum Press, New York, p 447Google Scholar
  4. Davis RH (1984) Neurospora Newslett 31:21Google Scholar
  5. Hastie AC (1970) Nature (London) 226:771Google Scholar
  6. John MA, Peberdy JF (1984) Enzyme Microbiol 6:386–389Google Scholar
  7. Johnstone IL, Hughes SC, Clutterbuck AJ (1985) EMBO J 4:1307–1311Google Scholar
  8. Käfer E (1961) Genetics 46:1581–1609Google Scholar
  9. Käfer E, Upshall A (1973) J Hered 64:35–38Google Scholar
  10. Miller BL, Miller KM, Timberlake WE (1985) Mol Cell Biol 5:1714–1721Google Scholar
  11. Pontecorvo G, Käfer E (1958) Adv Genet 9:71–104Google Scholar
  12. Pontecorvo G, Roper JA, Hermmons LM, MacDonald KD, Bufton AWJ (1953) Adv Genet 5:141–238Google Scholar
  13. Rigby PWJ, Dieckmann M, Rhodes C, Berg P (1977) J Mol Biol 113:237–251Google Scholar
  14. Southern EM (1975) J Mol Biol 98:503–517Google Scholar
  15. Tilbum J, Scazzochio C, Taylor GG, Labicky-Zissman JH, Lockington RA, Davis RW (1983) Gene 26:205–221Google Scholar
  16. Turner G, Ballance DJ, Ward M, Beri RK (1985) In: Timberlake WE (ed) Molecular genetics of filamentous fungi. Liss, New YorkGoogle Scholar
  17. Upshall A, Giddings B, Mortimore ID (1977) J Gen Microbiol 100:413–418Google Scholar
  18. Yelton ME, Timberlake WE, Van den Hondel, CAMJJ (1985) Proc Natl Acad Sci USA 82:834–838Google Scholar

Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • Alan Upshall
    • 1
  1. 1.ZymoGenetics, Inc.SeattleUSA

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