Interaction between abiotic factors and the biological clock: induction of seasonal algal growth

• Grant number: 16/20040-5
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: December 28, 2016
• End date: August 27, 2017
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal Investigator: Carlos Takeshi Hotta
• Grantee: Cícero Alves Lima Júnior
• Supervisor: François-Yves Bouget
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Observatoire Océanologique de Banyuls/Mer, France
• Associated to the scholarship: 13/05301-9 - Study on the interactions between the biological clock and desiccation in photosynthetic eukaryotes, BP.DR

Abstract

Green algae are photosynthetic eukaryotes with great importance in the trophic chain and in the biogeochemical cycles in all aquatic ecosystems. In temperate oceans, the drastic increase in phytoplankton growth rate in the winter - spring transition is known as algal bloom. The increase of day length during spring is a key factor in the induction of algae growth. One signalling pathway involved in the measuring of day length is the biological clock. These endogenous clocks are essential for the coordination of the external rhythms and physiological cycles. The green algae Ostreococcus tauri has a minimal clock and has simpler regulatory networks than known photosynthetic models. The already recorded blooms of this species, together with its ease to handle as a genetic model in the laboratory makes this picoeukaryote the right model for simulating algal bloom and for the discovery of mechanisms that control the interaction between abiotic factors and the cell cycle. The main goal of this project is to verify at transcriptional and translational levels how clock genes regulate seasonal growth rates of the green microalgae Ostreococcus tauri under different combinations of abiotic conditions, such as day length, temperature and salinity. Cell growth will be measured in sterile and enriched natural seawater. Luciferase mutants will be made in order to measure the promoter activity of key clock genes in the laboratory of microbiological oceanography coordinated by Prof François-Yves Bouget. This project will allow the student to learn the techniques that allow the genetic manipulation of Ostreococcus tauri, and to calculate the effects of abiotic stresses in the expression of main clock genes expression. This will allow the candidate to develop his abilities and knowledge in algae chronobiology and its influence in the algal physiology. The expected results will contribute to a better understanding about the algal blooms and give information for its management, damage mitigation, and improve high density photobioreactors use. Ostreococcus tauri has already demonstrated a great potential biofuels and metabolites prospection. (AU)