US-AUSTRALIAN ACADEMIES JOINT WORKSHOP
US-AUSTRALIAN ACADEMIES JOINT WORKSHOP ON VERTEBRATE COMPARATIVE GENOMICS
Beckman Conference Centre, Irvine, California, 23-25 May 2007
A potent antimicrobial protein expressed in wallaby milk
by Ben Cocks (Jianghui Wang, Jane C. Whitley)
Dr Cocks is the Research Director of Animal Genetics and Genomics within the Victorian State Government (Department of Primary Industries). The team of 45 staff apply genomics and new technologies to research animal health, animal genetics, animal biodiversity, and the discovery of bioactive proteins for human health. Prior to 2004, Dr Cocks’ worked at Incyte Inc. and DNAX Research Institute in California, and the University of Melbourne, where he discovered new pathways central to allergic and inflammatory diseases. Dr Cocks was trained in Biochemistry at the University of Melbourne.
We are investigating the potential of milk components to influence mammalian development and health, and are using genomics approaches to identify new bioactives for human use. We are looking primarily at bovine milk as a commercial source, but are also using marsupial lactation since it can reveal evolutionally conserved mechanisms in mammals, and because marsupials rely on milk for extended periods of development. For example, the young of the tammar wallaby are born immature after a short gestation period and when born lack an adaptive immune system. We used a bioinformatics approach to identify a number of immune and anti-microbial components in a marsupial EST database derived from genes expressed in the wallaby mammary gland at different stages of lactation. We identified a novel wallaby anti-microbial protein (AGG01) expressed in the early stages of lactation. A direct ortholog to AGG01 is not present in published eutherian genomes, the most closely related genes being others found in the wallaby genome. The gene expression pattern of AGG01 and lysozyme in the mammary gland during lactation suggest that there are two stages of increased immune transfer in the tammar wallaby coinciding with the foetus leaving the womb and the pouch young leaving the pouch. Functional in vitro studies using synthetic forms of AGG01 revealed potent anti-microbial activity against gram-positive bacteria and gram-negative bacteria and a fungus. These may aid the pouch young in adaptation to the environment and increase resistance to potential pathogens. The finding may provide new mechanisms for tackling antibiotic resistant pathogens.
Contact details:
Department of Primary Industries, Victoria
475 Mickleham Road, Attwood, Victoria 3049, Australia
Tel: +61 3 9217 4405
Fax: +61 3 9217 4212
Email: ben.cocks@dpi.vic.gov.au
