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Inactivation of DNA sequences in Aspergillus nidulans through non-linked duplication

M.A.A. Castro-Prado^I; T.M.A.D. Zucchi^II

^IDepartamento de Biologia Molecular e Genética, Fundação Universidade Estadual de Maringá, 87015 Maringá, PR, Brasil
^IIDepartamento de Parasitologia, Instituto de Ciências Biomédicas, Av. Prof. Lineu Prestes, 1374, Cidade Universitária, Universidade de São Paulo, 05508-900 São Paulo, SP, Brasil. Send correspondence to T.M.A.D.Z.

ABSTRACT

This paper describes a new system in Aspergillus nidulans that detects and alters duplicated DNA sequences in haploid nuclei of a premeiotic phase, before kariogamy. A similar system has previously been demonstrated in N. crassa, named "Rearrangements induced premeiotically" (RIP).
RIP acts heterogenously on the genes present in the duplication, promoting lethality and originating barren cleistothecia. Such strain have proved to be excellent system for molecular and classical genetic studies, as they are specialized in inactivating abnormally duplicated genes. In our study only classical genetic experiments

Keywords: DNA; Aspergillus nidulans; Non-linked duplication.

REFERENCES

Cambareri, E.G., Singer, M.J. and Selker, E.U. (1991). Recurrence of repeat-induced point mutation (RIP) in Neurospora crassa. Genetics 127: 699-710.

Castro-Prado, M.A.A. and Zucchi, T.M.A.D. (1991). Meiotic segregation of a recessive gene (wA2) included in a Dp (II-I) of Aspergillus nidulans. Braz. J. Genet. 14: 249-260.

Castro-Prado, M.A.A. and Zucchi, T.M.A.D. (1992). Characterization of the Dp (II, I) duplication in Aspergillus nidulans: presence of the Acr A1 gene and its regulatory transcription sequence in the transposed segment. Braz. J. Genet. 15: 777-788.

Clutterbuck, A.J. (1970). Aspergillus locus and letters and alleles numbers. Aspergillus Newsletter 11: 25-33.

Debuchy, R., Coppin-Raynal, E., Le Coze, D. and Brygoo, Y. (1988). Chromosome walking towards a centromere in the filamentous fungus. Podospora anserina: cloning of a sequence lethal at a two-copy state. Curr. Genet. 13: 105-111.

Fincham, J.R.S. (1989). Transformation in fungi. Microbiol. Rev. 53: 148-170.

Goyon, C. and Faugeron, G. (1989). Targeted transformation of Ascobolus immersus and de novo methylation of the resulting duplicated DNA sequences. Mol. Cel Biol. 9: 2818-2827.

Grayburn, W.S. and Selker, E.U. (1989). A natural case of RIP: Degeneration of DNA sequence in an ancestral tandem duplication. Mol. Cell. Biol. 9: 4416-4421.

Pontecorvo, G., Roper, J.A., Remuons, L.M., McDonald, K.D. and Button, A.W.J. (1953). The genetics of Aspergillus nidulans. 5: 141-238.

Selker, E.U. and Garrett, P.W. (1988). DNA sequence duplications trigger gene inactivation in Neurospora crassa. Proc. Natl. Acad. Sri. USA 85: 6870-6874.

Selker, E.U. and Stevens, J.M. (1985). DNA methylation at asymmetric sites is associated with numerous transition mutations. Proc. Nail. Acad. Sci. USA 82: 8114-8118.

Selker, E.U., Cambareri, E.B., Jensesn, B.C. and Haak, K.R. (1987a). Rearrangement of duplicated DNA in specialized cells of Neurospora. Cell. 51: 741-752.

Selker, E.U., Jensen, B.C. and Richardson, G.A. (1987b). A portable signal causing faithful DNA methylation de novo in Neurospora crassa. Science 238: 48-53.

Van de Vate, C. and Jansen, G.J.O. (1978). Meiotic recombination in a duplication strain of Aspergillus nidulans. Genet. Res. 31: 29-52.