Efficiency of Vibrio parahaemolyticus tdh gene expression depends upon two point mutations in its promoter region

Efficiency of Vibrio parahaemolyticus tdh gene expression depends upon two point mutations in its... A molecular study of Vibrio parahaemolyticus clinical isolates containing the thermostable direct hemolysin (Tdh) gene and the Tdh-related hemolysin (Trh) gene have been conducted. Southern blot hybridization revealed that in the genomes of strains carrying the determinants of both hemolysins (tdh + trh +) the tdh gene is presented by a single copy while tdh + trh − strains have two copies (tdh1 and tdh2). All investigated tdh + trh + and some tdh + trh − strains did not express the tdh gene (Kanagawa-negative, KP−) or expressed it weakly and inconstantly (Kanagawa-intermediate, KP±) in contrast to several Kanagawa-positive (KP+) strains. To establish the reasons for the KP−/± phenotypes we sequenced tdh, tdh1 and tdh2 genes of 13 strains isolated in Russia and neighbouring foreign countries followed by bioinformatics analysis of the obtained sequences in comparison with those of a number of strains presented in GenBank. The results revealed that poor expression of the tdh gene depends not only on a single point mutation in the promoter region (substitution of A to G in the −35 sequence) as it was believed earlier, but to the same extent on a second substitution (G to A at −3 nucleotide position from the t-10 sequence) which appeared to be sufficient in the absence of the first one. Therefore, a reversion of KP-/± strains to KP+ actually may occur as a result of a single point back mutation, and such strains are to be considered as potentially dangerous. Those bearing both substitutions may reverse with less probability as this process requires two simultaneous mutations. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Russian Journal of Genetics Springer Journals

Efficiency of Vibrio parahaemolyticus tdh gene expression depends upon two point mutations in its promoter region

Loading next page...
SP MAIK Nauka/Interperiodica
Copyright © 2012 by Pleiades Publishing, Ltd.
Biomedicine; Human Genetics; Animal Genetics and Genomics; Microbial Genetics and Genomics
Publisher site
See Article on Publisher Site


You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.



billed annually
Start Free Trial

14-day Free Trial