Transposable elements Paul Kalitsis. History Barbara McClintock 1940s.
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Transcript of Transposable elements Paul Kalitsis. History Barbara McClintock 1940s.
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 henryi
David 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