Variable lipoprotein genes of Mycoplasma agalactiae are activated in vivo by promoter addition via site-specific DNA inversions.

ABSTRACT: Mycoplasma agalactiae, the etiological agent of contagious agalactia of small ruminants, has a family of related genes (avg genes) which encode surface lipoprotein antigens that undergo phase variation. A series of 13 M. agalactiae clonal isolates, obtained from one chronically infected animal over a period of 7 months, were found to undergo major rearrangement events within the avg genomic locus. We show that these rearrangements regulate the phase-variable expression of individual avg genes. Northern blot analysis and reverse transcription-PCR showed that only one avg gene is transcribed, while the other avg genes are transcriptionally silent. Sequence analysis and primer extension experiments with two M. agalactiae clonal isolates showed that a specific 182-bp avg 5' upstream region (av

SUBMITTER: Flitman-Tene R 

PROVIDER: S-EPMC162021 | biostudies-literature | 2003 Jul

REPOSITORIES: biostudies-literature