The DNA form of a retroviroid-like element is involved in recombination events with itself and with the plant genome.
Carnation small viroid-like RNA (CarSV RNA) is unique among plant viroid-like RNAs in having a homologous DNA counterpart. In the present study, we found the most abundant CarSV DNA form (275 nt) coexisting with other smaller and longer-than-unit forms. Further analysis of PCR-amplified products revealed the presence of CarSV DNA-related sequences integrated in the plant genome, fused to microsatellite-like genomic sequences. Six to seven nucleotides at the boundaries in the CarSV DNA sequence could be found in the genomic sequences and also delimiting the boundaries of an enlarged version with partial duplication. This suggests that a common mechanism might have played a role in their emergence, namely, polymerase pausing and switching between stretches of homologous sequences. These plants also contained deleted CarSV DNA mutants with boundaries near those observed with fused sequences.
Hegedus
Krisztina
K
Agricultural Biotechnology Center, Gödöllo, H-2100 Szent-Györgyi A. u. 4, Hungary.
Dallmann
Géza
G
Balázs
Ervin
E
D001483:Base Sequence; D018744:DNA, Plant / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics*; D029749:Dianthus / Q000235:genetics* / Q000821:virology*; D018745:Genome, Plant; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics; D011995:Recombination, Genetic; D012689:Sequence Homology, Nucleic Acid; D014772:Viroids / Q000235:genetics*
D018744:DNA, Plant; D004279:DNA, Viral; D012367:RNA, Viral