Conference presentation
Inactivation of the IrrA gene in Synechococcus elongatus by means of insertional mutagenisis
23 Apr 2009
Abstract
The cyanobacterium Synechococcus elongatus PCC 7942 is a member of the pico-phytoplankton in freshwater environments. Cyanobacteria are notable for several reasons. First, they carry out plantlike oxygenic photosynthesis for the purpose of producing carbohydrates, and therefore contribute significantly to the primary productivity of their habitat. Cyanobacteria also have functions in Proterozoic oil deposits, various fuels, nitrogen fertilization for crops, and health supplements. During the Archaean and Proterozoic eras, cyanobacteria helped to create a more oxygenatedenvironment. Through genome sequence analysis, it was determined that this organism contains a gene that encodes a putative member of the LysR family of transcriptional regulators (LTTRs), known specifically as the IrrA gene. A hallmark of this family of transcriptional activators is that they control the expression of an adjacent, but divergently transcribed gene. We hypothesize that this IrrA gene regulates the expression of the adjacent and divergently transcribed orfG gene in this organism, which is believed to be a transcriptional growth factor. To verify this, we have created a Synechococcus strain deficient in IrrA functionality by means of insertional mutagenesis via introducing a chloramphenicol antibiotic cassette inside the coding region of the IrrA. This knockout strain will be used to observe possible phenotypic changes in S. elongatus as compared to the wild type organisms in competitive growth assays such as high versus low light conditions as well as temperature variations and nutrient availability to determine various stresses which could playa role in the growth of this organism. Furthermore, the levels of orfG mRNA in this knockout will be used to determine how IrrA and light availability affect the expression of this growth factor. The details of the cloning approach and mutagenesis strategy are presented and discussed in this presentation. The results of this experimentation will help explain the interesting pattern of LTTR regulation in the DNA region of S. elongatus encoding the adjacent yet divergently transcribed IrrA and or Genes.
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Details
- Title
- Inactivation of the IrrA gene in Synechococcus elongatus by means of insertional mutagenisis
- Creators
- Viren Doshi - Drexel UniversityShivanthi Anandan - Drexel University
- Resource Type
- Conference presentation
- Language
- English
- Academic Unit
- Biology
- Other Identifier
- 991014632334704721