Structural instability of a transgene locus in tobacco is associated with aneuploidy. [Erratum: Jan 1997, v. 11 (1), p. 167.]
1996
Papp, I. | Iglesias, V.A. | Moscone, E.A. | Michalowski, S. | Spiker, S. | Park, Y.D. | Matzke, M.A. | Matzke, A.J.M.
This paper describes molecular and cytogenetic evidence for the instability of a transgene locus that is present on the triplicated chromosome in an aneuploid tobacco line. This instability was manifested in several ways in trisomics including a major chromosome rearrangement that was detectable cytogenetically, smaller scale DNA rearrangements that occurred both germinally and somatically, and methylation/epigenetic silencing. In a deletion derivative of the locus, DNA breakpoints were found in AT-rich regions. One of these regions binds to nuclear scaffolds in vitro, suggesting a possible role for aberrant topoisomerase II cleavage in destabilization of the locus. The implications of increased chromosome instability in aneuploids for plant karyotype evolution and human carcinogenesis are discussed.
显示更多 [+] 显示较少 [-]