Monday November 20 2006

Sex Chromosomes and the Future of Men

Professor Jenny Graves

In humans and other mammals, females have two X chromosomes, and males a single X and a Y. The X is a decent, ordinary chromosome, though it has more than its fair share of genes involved in male sex and reproduction – and maybe sexual behaviour and intelligence. But the Y is a genetic wasteland – small and full of genetic junk, bearing only 45 genes. It does, however, bear an important gene (SRY) that switches on the development of testis, which pumps out male hormones – this is what makes the Y chromosome male determining.But the human Y chromosome is running out of time – at the current rate of degradation, the Y chromosome will likely lose its last 45 genes in just 10 million years. What happens when SRY disappears? Would this be the end of the line for our species? The good news is that SRY has been lost in some rare rodents and replaced by a new sex determining gene – we don’t know what or where. So as the human Y runs out of options, new sex determining genes may evolve, maybe leading to different hominid species.

  • Time: 6:30 pm to 7:30 pm
  • Venue: Ithaca Room, City Hall
  • Refreshments: There will be complimentary drinks and nibblies following the talk, and Jenny will be available to answer any questions.
  • Questions? Contact Jennifer (0408 796 357 or

Professor Jenny Graves is a geneticist who works on Australian animals – kangaroos and platypus are a specialty. Her group uses the distant relationship ofAustralian mammals from humans to understand how genes and chromosomes evolved and how they work in all mammals including humans. Her laboratory is famous for using this unique perspective to explore the origin, function and (dismal) fate of human sex chromosomes, and even to discover novel human genes. She has produced three books and 300 research articles. Jenny heads the Comparative Genomics Research group in the Research School of Biological Sciences at ANU, and directs the ARC Centre for Kangaroo Genomics. She has received a number of honours and awards, including the Macfarlane Burnet medal in 2006, and is a Fellow of the Australian Academy of Science, and 2006 L’Oreal-UNESCO Laureate.