Wild chromosomal variants in Aspergillus nidulans
1996
Geiser, D.M. | Arnold, M.L. | Timberlake, W.E. (Georgia Univ., Athens (USA). Dept. of Genetics)
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 (mb). Another isolate had undergone a non-reciprocal translocation of about 1.6 mb of chromosome 6 onto chromosome 8. 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.
显示更多 [+] 显示较少 [-]