3.8.3 GENOME PROJECTS

• Sequencing genomes -

  Sequencing projects determine the complete genome sequence of an organism. Success depends on complexity of the organism and technology available.

  Improvements in technology have allowed sequencing of the genomes of a variety of organisms. 

  Gene sequencing methods only work on fragments of DNA, so genome has to be broken into smaller pieces first. The smaller pieces are sequenced and then put back in order to give the sequence of the whole genome.
• The Human Genome Project mapped entire human genome.

  • Improve understanding of genetic factors in human disease, to develop new ways to diagnose and treat illness.
• Sequencing proteomes - Simple organisms

  • Determining genome allows sequences of the proteins that derive from the genetic code to be determined.
  • Simple organisms (eg. bacteria) don’t have much non-coding DNA. Easier to determine proteome from DNA sequence of genome. 
  • Useful in medical research and development - eg. identifying protein antigens for vaccines.
• Sequencing proteomes - Complex organisms

  • Contain non-coding DNA and regulatory genes (determine when genes switched on/off). 
  • So more difficult to translate genome into proteome, as hard to find the coding DNA among non-coding and regulatory DNA. 
  • Current work on the human proteome.
• Sequencing methods now often automated, more cost-effective and can be done on a large scale. Continuously updated.

  Newer, faster techniques available make sequencing whole genomes much quicker.