RRC ID 244
Author Koga A.
Title Transposition mechanisms and biotechnology applications of the medaka fish Tol2 transposable element.
Journal Adv. Biophys.
Abstract The Tol2 element of the medaka fish is a member of the hAT (hobo/Activator/ Tam3) transposable element family. About 20 copies are present in the medaka fish genome and, unlike many other hAT family elements, virtually all the copies are autonomous or potentially autonomous, containing an intact transposase gene. Excision of Tol2 is not precise at the nucleotide sequence level, excision foot-prints being heterogeneous. In more than half of excision events, however, breakage and rejoining of DNA molecules occur within the 8-bp target site duplication region, removing the entire Tol2 sequence and retaining parts of the target site duplications. In the reminder of the excision events, either the left or the right terminal region is left and the other end is lost together with its flanking region. Thus, there might be two different mechanisms of excision. Insertion of Tol2 occurs without detectable preference for target sequences and creates a target site duplication of exactly 8 bp. In addition to the medaka fish and related fish species, Tol2 transposes in mammalian cells in culture, including human and mouse examples. Autonomy is also retained in these cases. A gene transfer vector using Tol2 has already been established in fish. Foreign DNA fragements inserted in Tol2 can be efficiently delivered to the chromosomes by transposition. The latest version of the vector contains, between the Tol2 terminal regions, a bacterial drug-resistance gene and a plasmid replication origin. This allows simple recovery of insertion regions, as plasmid DNA, from genomic DNA of transformants. Modification of this system for other vertebrates, especially for mammals, are now in progress.
Volume 38
Pages 161-80
Published 2004
PII S0065-227X(04)80151-5
PMID 15493333
MeSH Amino Acid Sequence Animals Animals, Genetically Modified Base Sequence Biotechnology / methods* Chromosomes / ultrastructure DNA / genetics DNA Transposable Elements* Exons Gene Transfer Techniques Genetic Variation Genetic Vectors Models, Biological Models, Genetic Molecular Sequence Data Mutagenesis Mutagenesis, Site-Directed Mutation Oryzias / genetics* Plasmids / metabolism Repetitive Sequences, Nucleic Acid Sequence Homology, Nucleic Acid Transposases / genetics
Times Cited 11
Medaka NA