Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | PubMed Central |
|---|---|
| Author | Knapp, S. Mekalanos, J. J. |
| Abstract | Expression of virulence factors by Bordetella pertussis is altered by environmental signals (antigenic modulation) and is dependent on an activator encoded by a gene called vir. We have used TnphoA (Tn5 IS50L::phoA) gene fusions to define two sets of genes whose expression is either activated (vag loci) or repressed (vrg loci) by modulation signals. Both groups of genes appear to be regulated by the vir gene product in that, in the absence of modulators, null mutations in vir lead to the repression of vag gene fusions and derepression of vrg gene fusions. Mutants of B. pertussis were isolated that constitutively express virulence factors in the presence of the modulator MgSO4, nicotinic acid, or low incubation temperature. We designate the gene that carries such mutations mod (modulation) and have characterized one (mod-1) of these mod constitutive mutations. A method was developed for the insertional inactivation of the vir gene by using the integration of a suicide replicon. Inactivation of the vir gene in the mod-1 mutant, followed by transcomplementation with the cloned wild-type vir gene, gives the Mod-1 constitutive phenotype, showing that the mod-1 mutation defines a gene distinct from vir. The gene carrying the mod-1 mutation is linked to vir and was cloned on a recombinant cosmid (pLAF-C1) which transcomplements the vir-1::Tn5 mutation in B. pertussis 347. Introduction of pLAF-C1 into vir mutant and vir+ B. pertussis strains also gives the Mod-1 constitutive phenotype, indicating that mod-1 is a dominant allele. These data suggest that the mod gene product could have sensory functions for the environmental signals that affect the expression of vir-regulated genes of B. pertussis. The mod constitutive strains and plasmids described here also have applications in pertussis vaccine development. |
| Starting Page | 5059 |
| File Format | |
| ISSN | 10985530 |
| e-ISSN | 10985530 |
| Journal | Journal of Bacteriology |
| Issue Number | 11 |
| Volume Number | 170 |
| Language | English |
| Publisher Date | 1988-11-01 |
| Access Restriction | Open |
| Subject Keyword | Research in Higher Education |
| Content Type | Text |
| Resource Type | Article |
| Subject | Molecular Biology Microbiology |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|