Wild chromosomal variants in Aspergillus nidulans
Author: Geiser, D. M.; Arnold, M. L.; Timberlake, W. E.
Year: 1996
Journal: Current Genetics
Volume: 29
Issue: 3
Pages: 293-300
Abstract
Pulsed-field gel electrophoresis and a chromosome-specific
cosmid DNA library were used to determine the karyotypes of
wild-type Aspergillus nidulans isolates from around the world.
Overall, little structural variation was found, with a few
major exceptions. One isolate possessed a non-essential
B-chromosome of about 1.0 million base pairs (nib). Another
isolate had undergone a non-reciprocal translocation of about
1.6 mb of chromosome VI onto chromosome VIII. Other than these
chromosomal differences, these isolates appeared phenotypically normal.
To analyze its effects on meiosis, the translocation isolate
was outcrossed with another wild-type derivative that had
a "normal" electrophoretic karyotype. This cross produced
a range of phenotypes, including duplicated progeny that had
a "barren" phenotype similar to that described for
Neurospora partial disomics. The duplication was somewhat
vegetatively unstable. This is the first association of
sterility with chromosomal duplication in A. nidulans.