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Ds excision from extrachromosomal geminivirus vector DNA is coupled to vector DNA replication in maize
Author(s) -
Wirtz Uwe,
Osborne Brian,
Baker Barbara
Publication year - 1997
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1997.11010125.x
Subject(s) - extrachromosomal dna , biology , dna replication , microbiology and biotechnology , vector (molecular biology) , origin of replication , genetics , dna , gene , plasmid , recombinant dna
Analysis of transposition products generated after Activator (Ac) excision from the P locus in maize suggest that Ac excises either during or after replication of the P locus. The frequency of excision of the non‐autonomous Ac derivative, Dissociation ( Ds ), from extrachromosomal replicating and nonreplicating vector DNAs in transfected black mexican sweet maize protoplasts was compared to assess directly a role of extrachromosomal vector DNA replication in Ds excision. Replicating (rep + ) and non‐replicating (rep − ) vector DNAs comprised a Ds element that harbored a geminivirus, wheat dwarf virus (WDV), origin of replication and WDV genes required for viral DNA replication (rep + ) or mutant, inactive derivatives of these genes (rep − ). Excision of Ds was detected only in those cell nuclei co‐transfected with the replicating Ds ‐vector DNA and a transposase expression vector. Quantitative reconstruction experiments showed that Ds excised at least 3 × 10 5 ‐fold more frequently from replicating vector DNA as compared with nonreplicating vector DNA. Therefore, these results provide direct evidence for a coupling of Ds excision from extrachromosomal vector DNA to vector DNA replication in maize.