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
in English
| LILACS
| ID: lil-164707
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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Index:
LILACS (Americas)
Main subject:
Aspergillus nidulans
/
Ultraviolet Rays
/
Crossing Over, Genetic
/
Diploidy
/
Alleles
/
Homozygote
/
Mitosis
/
Mutation
Language:
English
Journal:
Rev. bras. genét
Journal subject:
Genetics
/
Histology
Year:
1994
Type:
Article
/
Project document
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