A new mutagenesis assay system based on the phage 434 cI gene carried on a low-copy number plasmid was used to investigate the effect of UV light on intermolecular transposition of IS10. Inactivation of the target gene by IS10 insertion was detected by the expression of the tet gene from the phage 434 PR promoter, followed by Southern blot analysis of plasmids isolated from TetR colonies. UV ir...

The transposition frequencies of Tn10 elements from the bacterial chromosome to an F epitome decrease 40% for every kilobase increase in transposon length. The basis for this relationship is not known. We have now examined complemented transposition of defective Tn10 elements off small multicopy plasmids. We find that length dependence in this situation is either reduced or absent, depending on...

Transposable elements are often considered as selfish DNA sequences able to invade the genome of their host species. Their evolutive dynamics are complex, due to the interaction between their intrinsic amplification capacity, selection at the host level, transposition regulation, and genetic drift. Here, we propose modeling the first steps of TE invasion, i.e., just after a horizontal transfer,...

The bacterial transposon Tn7 encodes five transposition genes tnsABCDE. We report a simple and rapid procedure for the purification of TnsC protein. We show that purified TnsC is active in and required for Tn7 transposition in a cell-free recombination system. This finding demonstrates that TnsC participates directly in Tn7 transposition and explains the requirement for tnsC function in Tn7 tra...

Long ridiculed for their racial hybridity, India’s Anglo-Indians—a mixed race people—were called ‘Dingos’ and instructed rudely to “Go to Australia” after India won her Independence from the British in 1947. Although their first port of escape from India was Great Britain, thousands of Anglo-Indians left the Indian subcontinent (India, Pakistan and Sri Lanka) in the second wave of migration, i....

Correspondence to: Beatriz Silva Câmara Mattos Faculdade de Odontologia Universidade de São Paulo Av. Lineu Prestes, 2227 05589-900 Cidade Universitária, São Paulo, SP Brazil Phone: (011) 55479547 Fax: (011) 51812229 E-mail: [email protected] Abstract Tooth transposition is an anomaly in the position of teeth where two teeth of the same maxillary quadrant change their position in the dental arch....

In Escherichia coli, the frequencies of IS50 and Tn5 transposition are greater in Dam- cells than in isogenic Dam+ cells. IS50 transposition is increased approximately 1,000-fold and Tn5 transposition frequencies are increased about 5- to 10-fold in the absence of Dam methylation. However, in cells that are deficient for both integration host factor (IHF) and Dam methylase, the transposition fr...