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Pili Formation in Filamentous Cyanobacteria / CHARLEY ROBINSON

Swansea University Author: CHARLEY ROBINSON

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Abstract

Pili are flagella-like appendages that can be found on the surface of bacteria. Type 4 pili (T4P) are a form of pili produced that aid in functions such as cell motility, which cyanobacteria rely on due to their lack of flagella. This is carried out through various Pil proteins which are responsible...

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Published: Swansea, Wales, UK 2023
Institution: Swansea University
Degree level: Master of Research
Degree name: MRes
Supervisor: Rivera, Miguel. L., Llewellyn, Carole. and Ortiz-Urquiza, Almudena.
URI: https://cronfa.swan.ac.uk/Record/cronfa63572
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Abstract: Pili are flagella-like appendages that can be found on the surface of bacteria. Type 4 pili (T4P) are a form of pili produced that aid in functions such as cell motility, which cyanobacteria rely on due to their lack of flagella. This is carried out through various Pil proteins which are responsible for mechanisms such as pilus assembly, extension/retraction of the pilus rod, along with others working as response regulators for twitching motility. To investigate this, the filamentous species Chlorogloeopsis fritschii PCC 6912 was used to observe gene expression for these Pil proteins to understand the phototactic response of pili formation under UV-B and far-red light as these wavelengths of light can be found throughout their natural environment. Under UV-B, 64.29% showed >75% increase in gene expression with 40.0% of these pil genes showing significant upregulation. Under far-red, 45.16% showed a >75% decrease with 51.6% showing significant downregulation, specifically impacting the Pil proteins responsible for the formation of the pilus rod. These results suggest a phototactic response of C.fritschii PCC6912 with regards to pili formation, however not being triggered by all wavelengths of light that could be found throughout their habitat.
Keywords: Filamentous cyanobacteria, pili, UV-B, far-red, Chlorogloeopsis fritschii
College: Faculty of Science and Engineering