A new method to detect potential genotoxic agents using mitotic crossing-over in diploid strains of Aspergillus nidulans
Rev. bras. genét
; 17(4): 371-6, dez. 1994. ilus, tab
Article
em En
| LILACS
| ID: lil-164707
Biblioteca responsável:
BR1.1
RESUMO
This paper presents a new method for detecting mitotic crossing-over in Aspergillus nidulans, based on the "homozygosity index" (HI) of recessive genes originally present in hetrozygosis in diploid strains, which occurs after mitotic crossing-over between the marker in question and the centromere. Since homozygous diploids (-/-) for auxotrophic markers can not grow in MM, homozygotization can be demonstrated by distorted mitotic segregation of the alleles involved. Two similar diploid strains (UT 448/UT 184 and Z1//UT 184), which differ by a chromosomic duplicate segment transposed from chromosome II to I in the Z1 haploid strain, were used. This excess of genetic material confers to the Z1 mutant the uvs character and makes Z1//UT 184 more unstable and sensitive to genotoxic agents, as evidenced by its high spontaneous recombinational index.
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Índice:
LILACS
Assunto principal:
Aspergillus nidulans
/
Raios Ultravioleta
/
Troca Genética
/
Diploide
/
Alelos
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Homozigoto
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Mitose
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Mutação
Idioma:
En
Revista:
Rev. bras. genét
Assunto da revista:
GENETICA
/
HISTOLOGIA
Ano de publicação:
1994
Tipo de documento:
Article
/
Project document