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Sonal Shewaramani

B.Sc., M.Sc
Ph.D. co-supervised with Dr. Christina Moon (AgResearch)

Contact

physical: AgResearch Grasslands Research Centre // Palmerston North
tel: +64 6 351 8326 // email: sonal.shewaramani(at)agresearch.co.nz

Background

After obtaining my Bachelor’s degree in Genetics from the University of Toronto (Toronto, Canada), I did my Master’s degree at the Australian National University (Canberra, Australia). During my time in Canberra, I investigated microsatellite markers for Tulasnella, a mycorrhizal fungus occurring in the roots and stems of Australian orchids. The lack of suitable genetic markers made it difficult to study Tulasnella at the species and population level. Thus, my project’s aim was to help develop microsatellite markers for future studies involving this endophytic fungus.

Research

My research uses experimental evolution to investigate the spontaneous mutation rate and mutation spectra of E. coli in the presence and absence of oxygen.

Life on earth has evolved by natural selection acting on variant individuals within populations, with mutations being the ultimate source of genetic variation. For organisms that experience changing environments, mutation rates and the types of mutations that arise can vary, which in turn, affect the opportunities for natural selection, adaptation and evolution as a whole. Facultative anaerobic bacteria can thrive in both the presence and absence of oxygen. However, oxidative stress is a significant cause of mutation where reactive oxygen species (ROS), a normal by-product of aerobic respiration, cause substantial DNA damage. In contrast, ROS levels are significantly lower during anaerobic respiration. Understanding how mutation rates and spectra vary in aerobic and anaerobic environments, will provide us with insights into the evolutionary process in these environments.

The aims of my project are thus to use whole genome re-sequencing and experimental evolution techniques to determine, compare and contrast the rates and spectra of mutations that arise in E. coli in aerobic and anaerobic environments.

This project is part of a Marsden funded study at AgResearch (Christina Moon) which aims to determine how air affects mutation and adaptation.

Sonal Shewaramani