The search for conjugative transposon in rumen bacterium Prevotella bryantii B14 | Iskanje konjugativnega transpozona v vampni bakteriji Prevotella bryantii B14

Inglés. Only few plasmids and bacteriophages have been described to date in ruminal prevotella strains, therefore it appears plausible that the genetic exchange in these organisms must exploit other routes. Large conjugative transposons make possible the gene exchange process in bacteria from the genus Bacteroides, the phylogenetic relatives of ruminal prevotellas. The access to fully or partially finished genome sequences of Bacteroides and Prevotella representatives made possible the search for conserved regions within putative conjugative transposons. Multiple sequence alignment of known and putative conjugative transposon gene sequences of Bacteroides thetaiotaomicron, Prevotella intermedia, Bacteroides fragilis and Tanerella sp. was used to locate partially conserved regions within most preserved conjugative transposition genes, traG, and to construct appropriate degenerated oligonucleotide primers. These were used to amplify genome fragments from ruminal prevotella strains. Sequence analysis of the subcloned PCR products revealed the presence of a hypothetical gene in the genome of Prevotella bryantii B14, similar to the ORF BF2880 from B. fragilis YCH46, which is a part of a large conjugative transposon. Inverse PCRs were designed and performed to confirm the initial findings. A partial map of P. bryantii B14 putative conjugative transposon region was constructed, indicating an intergeneric horizontal gene transfer.

Esloveno. Ker sevi rodu Prevotella iz vampa le izjemoma posedujejo plazmide in je opisanih le nekaj bakteriofagov, je zelo verjetno, da izmenjava genov pri teh organizmih vključuje druge poti. Veliki konjugativni transpozoni omogočajo prenos genov pri rodu Bacteroides, filogenetskih sorodnikih vampnih prevotel. Dostop do delno ali v celoti sekvenciranih genomov predstavnikov Bacteroides in Prevotella je omogočil iskanje ohranjenih regij znotraj domnevnih konjugativnih transpozonov. S poravnavo več sekvenc znanih ali domnevnih genov konjugativnih transpozonov iz vrst Bacteroides thetaiotaomicron, Prevotella intermedia, Bacteroides fragilis in rodu Tanerella smo določili delno ohranjene regije v najbolj ohranjenem genu konjugativne transpozicije, traG, in jih uporabili za izdelavo primernih začetnih oligonukleotidov za pomnoževanje dela gena pri vampnih sevih iz rodu Prevotella. Analiza sekvenc subkloniranih pomnožkov je pri P. bryantii B14 razkrila prisotnost hipotetičnega gena, podobnega odprtemu čitalnemu okvirju BF2880 seva B. fragilis YCH46, ki je del velikega konjugativnega transpozona. Z inverzno verižno reakcijo s polimerazo smo potrdili prvotne ugotovitve. Izdelali smo delno mapo regije domnevnega konjugativnega transpozona pri P. bryantii B14, ki nakazuje, da je prišlo do medrodovnega horizontalnega prenosa genov.