Factors acting on Mos1 transposition efficiency.
BACKGROUND
Mariner-like elements (MLEs) are widespread DNA transposons in animal genomes. Although in vitro transposition reactions require only the transposase, various factors depending on the host, the physico-chemical environment and the transposon sequence can interfere with the MLEs transposition in vivo.


RESULTS
The transposition of Mos1, first isolated from drosophila mauritiana, depends of both the nucleic acid sequence of the DNA stuffer (in terms of GC content), and its length. We provide the first in vitro experimental demonstration that MITEs of MLE origin, as small as 80 to 120-bp, are able to transpose. Excessive temperature down-regulates Mos1 transposition, yielding excision products unable to re-integrate. Finally, the super-helicity of the DNA transposon donor has a dramatic impact on the transposition efficiency.


CONCLUSIONS
The study highlights how experimental conditions can bias interpretation of mariner excision frequency and quality. In vitro, the auto-integration pathway markedly limits transposition efficiency to new target sites, and this phenomenon may also limit events in the natural host. We propose a model for small transposons transposition that bypasses DNA bending constraints.
Sinzelle
Ludivine
L
Université François Rabelais de Tours, GICC, UFR des Sciences & Techniques, Parc Grandmont, 37200 Tours, France. sinzellel@yahoo.fr
Jégot
Gwenhael
G
Brillet
Benjamin
B
Rouleux-Bonnin
Florence
F
Bigot
Yves
Y
Augé-Gouillou
Corinne
C
D000818:Animals; D001483:Base Sequence; D004251:DNA Transposable Elements / Q000235:genetics*; D004270:DNA, Circular / Q000737:chemistry / Q000235:genetics; D004330:Drosophila / Q000235:genetics*; D008954:Models, Biological; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011995:Recombination, Genetic; D013696:Temperature; D020079:Terminal Repeat Sequences / Q000235:genetics; D013997:Time Factors
D004251:DNA Transposable Elements; D004270:DNA, Circular