Presenter Profile
Anthony Poole
Professor
University of Auckland, School of Biological Sciences
Anthony Poole is a former recipient of a Monbusho research scholarship, where he worked on the developmental genetics of fruit flies at the University of Tokyo. He completed his PhD in Molecular Bioscience at Massey University before taking up an academic position at Stockholm University in Sweden, where he was awarded a Swedish Research Council Assistant Professorship and a Royal Swedish Academy of Sciences Research Fellowship. Following a move to the University of Canterbury, he was awarded a Royal Society of New Zealand Rutherford Discovery Fellowship. He is a past President of the New Zealand Society for Biochemistry and Molecular Biology, and former Director of the Bioinformatics Institute at the University of Auckland. He was made a full professor at the University of Auckland in 2017.
TALK TITLE
Towards creation of a bacterial genome with uracil as fourth base
KEYWORDS
Genomics, evolution, DNA
ABSTRACT
Genetic information in cells is stored as genes within DNA. DNA is made up of four building blocks, commonly referred to by their bases: A, G, C and T. To access and use the information in genes, a working copy of the gene is made from RNA. RNA is very similar to DNA, but differs in two important respects. One difference is the chemistry of the backbone sugar that gives RNA and DNA their names. In RNA, this is called ribose while DNA uses deoxyribose. The second difference is in the fourth base. In DNA, the fourth base is thymine (T) while in RNA it is uracil (U). It is thought that the earliest cells constructed their genomes from RNA, with DNA evolving later. We have previously proposed that DNA evolved from RNA in two steps. The first change was to the sugar, with replacement of U with T happening later in evolution.
The evolutionary history of DNA therefore suggests that early cells would have possessed genomes made from U-DNA. While some viruses do indeed have 'U-DNA' genomes, no one has demonstrated that cellular genomes could be constructed from U-DNA. To examine if this is plausible, we have created bacteria that are unable to synthesise T. We subjected these bacteria to experimental evolution to see how they adapt to the lack of T, and we are analysing the genome composition of these bacteria to see whether they have U in their genomes. We have found that we can use nanopore DNA sequencing to distinguish between U and T in synthetic DNA, and are now interested to know if we can detect U directly in the genomes of our bacteria. I will present our current progress on this project.