Mycobacterium tuberculosis H37Rv transposon library created.

2003 JAN 1 - (NewsRx.com & NewsRx.net) -- Researchers at pharmaceutical giant GlaxoSmithKline have created a library of Mycobacterium tuberculosis insertional mutants generated with the transposon Tn5370."

"The junction sequence between the transposon and the mycobacterial chromosome was determined, revealing the positions of 1329 unique insertions, 1189 of which were located in 351 different ORFs [open reading frames]. Transposition was not completely random and examination of the most susceptible genome regions revealed a lower-than-average G+C content ranging from 54 to 62 mol %," reported R.A. McAdam and colleagues.

"Mutants were obtained in all of the recognized M. tuberculosis functional protein-coding gene classes. About 30% of the disrupted ORFs had matches elsewhere in the genome that suggested redundancy of function," said the researchers.

"The effect of gene disruption on the virulence of a selected set of defined mutants was investigated in a severe combined immune deficiency (SCID) mouse model. A range of phenotypes was observed in these mutants, the most notable being the severe attenuation in virulence of a strain disrupted in the Rv1290c gene, which encodes a protein of unknown function." ...