Identification and sequence of an unstable DNA element in the entomopathogenic bacteria Photorhabdus temperata strain K122

Abstract

Aims: A search was conducted for a difference in genome composition between phenotypic variants of the insect pathogenic bacteria, Photorhabdus temperata. Methods: An unstable 300 bp fragment of DNA was identified by amplified fragment length polymorphism (AFLP) analysis, which was not, however, associated with phenotypic variation. Results: During prolonged culturing of the bacteria, one copy of the repeated fragment was deleted and a restriction site linked to one of the copies was lost or gained. The sequence did not show substantial identity to any in the database, but a 16‐bp region was identical to part of the marR gene of Escherichia coli. Significance and Impact of the Study: The work has implications for the understanding of genetic instability in this and other pathogenic species of bacteria. In addition, the complete unstable element may be useful as a genetic tool in Photorhabdus spp.

Plastic architecture of bacterial genome revealed by comparative genomics of Photorhabdus variants

“…In our study, we firstly demonstrated that the PV status (primary or secondary) is independent from global genomic architecture. This was consistent with previous studies analyzing specific genetic regions [ 28 , 38 , 39 ] and with partial genome studies [ 33 , 40 , 41 ], but this is the first time it has been demonstrated using a whole-genome approach.…”

“…Previous studies, incorporating local genetic [ 28 , 38 , 39 ] or nonexhaustive genomic comparisons [ 33 , 34 , 40 , 41 ], have not identified genomic differences within sets of PVs or CVs. We used the recently elucidated complete nucleotide sequence of the P. luminescens subspecies laumondii strain TT01 [ 42 ] to study systematically the link between phenotypic and genomic variations in clonal Photorhabdus variants.…”