Science at the Shine Dome 2010
New Fellows Seminar
Wednesday 5 May
Dr Marianne Frommer FAA
School of Biological Sciences, University of Sydney
Marianne Frommer received her PhD on the physical biochemistry of muscle proteins from the University of Sydney in 1976. After two years of teaching at the Cumberland College of Health Sciences, and a career interruption for child rearing, she took up a position as postdoctoral fellow and subsequently senior research fellow at the Royal Prince Alfred Hospital, Sydney. Her laboratory was located at the CSIRO Division of Biomolecular Engineering, where she carried out pioneering work on CpG islands and DNA methylation in mammalian genomes.
In 1994 Marianne changed direction, leaving mammalian genetics and moving to the University of Sydney, where she co-founded the Fruit Fly Research Centre and was its inaugural research director. She initiated molecular genetic studies on the Queensland fruit fly, the most important horticultural pest species in Australia. These studies have been responsible for defining the Australia-wide distribution of the species, and have provided important developments towards its control.
DNA methylation and the molecular biology of fruit flies
Two papers in 1975 (by Holliday and Pugh, and Riggs) described a mechanism by which methylation of cytosine in DNA could provide epigenetic information to cells – heritable information that can vary between cell types and is additional to the primary DNA sequence (the genetic information). My interest in DNA methylation arose because I noticed tissue-specific methylation in the direct genomic sequences of highly repeated human DNA. When PCR became available my colleagues and I worked out how to map cytosine methylation in DNA sequences, by first reacting genomic DNA with bisulphite and then amplifying each strand of the product. I was also involved in the discovery and sequence identification of CpG islands, which are important for locating genes in genomic DNA sequence data and for understanding DNA changes in cancer.
The fruit flies under discussion here are not the geneticist's friend, Drosophila, but the true fruit flies of horticultural importance. Almost nothing was known about the genetics and molecular biology of the Queensland fruit fly when the Fruit Fly Research Labs were set up. They have since provided information to agriculture and quarantine departments about the origin of infestations, and are currently working on molecular and genetic techniques to improve the sterile insect technique, the most important non-chemical method to control fruit flies on an area-wide basis. Investigating the genetics of the true fruit flies has also shown that Australia's fruit fly pests could be an unusual and very powerful model to study evolution and development, perhaps involving epigenetic mechanisms in insects.
