transposable elements
DESCRIPTION
Transposable elements. Paul Kalitsis. History. Barbara McClintock 1940s. History. Genetic loci could change position Theory of mobile or controlling elements Challenged the concept of a static genome Stopped publishing from 1953 Awarded the Nobel Prize in 1983. History cont’. - PowerPoint PPT PresentationTRANSCRIPT
Transposable elements
Paul Kalitsis
History
• Barbara McClintock 1940s
History
• Genetic loci could change position• Theory of mobile or controlling elements• Challenged the concept of a static
genome• Stopped publishing from 1953• Awarded the Nobel Prize in 1983
History cont’
• Identified in bacteria and yeast in the late 60s and early 70s
Junk or Selfish DNA
• No obvious role apart from self propagation
• Variations in genome size
Genome size
• C-value paradox• Maize 2,500 Mb• Arabidopsis 150 Mb• Lilium 35,000 Mb
Types of TEs
• DNA transposons• Retrotransposons• Endogenous retroviruses
Biemont & Vieira 2006 Nature
Lander 2001 Nature
genome.ucsc.edu
Function
• Development• Imprinting• Tissue differentiation• Evolution
Lilium henryiDavid SmythSchool of Biological SciencesMonash University
Dispersed repeat in L. henryi
• 3.5 x 1010 bp• Distributed throughout the genome• Retrotransposon 9.35 kb
gag RT RH INT
Selfish DNA
• Doolittle & Sapienza• Orgel & Crick (1980 Nature)
Genome defense
• Recombination and deletion• RNAi pathway
Epigenetic control
• Changes in DNA and/or protein• Gene expression• X-inactivation
Environment
• Stress• Nutrition• Chemicals
Morgan et. al. 1999 Waterland and Jirtle 2003
IAP
Avy
IAP
AvyMe Me
Biemont & Vieira 2006 Nature
Human disease
• 0.5 – 1%• Cancer• Haemophilia• Muscular dystrophy
Applications
• Mutagenesis• Gene delivery and therapy
Co-option
• Immune system• Placental development• Telomere maintenance• Centromere• Epilepsy• Early development
Acknowledgments
• Chromosome and Chromatin Group• Australian Research Council