Transpogenes: the transposition-like integration of short sequence DNA into the yeast 2 micron plasmid creates the STB locus and plasmid-size polymorphism.
The type-2 2 mu plasmid of industrial yeast strains exhibits extensive size polymorphism in the STB (plasmid stability) locus and IR (inverted repeat)-right region. Comparative DNA sequence analyses of STB alleles identified a 38-bp sequence flanked by a 25-bp direct repeat as the underlying structural motif. Variable unequal recombination within the direct repeat accounted for the observed polymorphism of STB alleles. IR-right polymorphism was observed to result from tandem duplication of a 22-bp sequence flanked by a 9-bp direct repeat. The flanking direct repeats marked both loci as originating from the transposition-like integration of short DNA fragments. We call these structures transpogenes and note that these are hybrid structures of host and foreign DNA which can evolve into functional loci.
Rank
G H
GH
Department of Biology, University of Saskatchewan, Saskatoon, Canada.
Xiao
W
W
Pelcher
L E
LE
D001483:Base Sequence; D005075:Biological Evolution; D004251:DNA Transposable Elements; D004271:DNA, Fungal / Q000235:genetics; D008969:Molecular Sequence Data; D010957:Plasmids; D012150:Polymorphism, Restriction Fragment Length; D012045:Regulatory Sequences, Nucleic Acid; D012091:Repetitive Sequences, Nucleic Acid; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D015003:Yeasts / Q000235:genetics*
D004251:DNA Transposable Elements; D004271:DNA, Fungal