Sequencing a genome

1
Sequencing a genome

• (a) outline the steps involved in sequencing the
  genome of an organism
• (b) outline how gene sequencing allows for
  genome-wide comparisons between individuals and
  between species

2
Genome size complexity
Increasing complexity
Viruses
Bacteria
Protozoa
Mammals
Plants
Inverterbrates

• Issues for consideration when sequencing
• DNA source
• Genome size
• Repeat content
• Duplications and inversions

• Issues for consideration when annotating
• Genome size
• Repeat content
• Splicing
• Genefinding resources
• Likely comparator species

3
Genome sequencing

• Sequencing involves
• DNA fragmenting into small pieces
• Sequence determination
• Assembly into large contiguous sequences
• Problems occur
• Cloning steps
• Bacterial transformation and amplification
• Sequencing chemistry
• Assembly of repetitive regions

4
Sequencing a Genome
5
Sequence coverage
Most genome sequences are not complete (not
finished). Whole Genome Shotguns are referred to
as having an X-fold coverage. Low coverage (2x)
is sufficient for gene discovery and some
regulatory element identification. High coverage
(6x) is good for gene annotation. There will
still be some missing genes. Finished sequence
has no gaps and is presumed to contain all
genes.
6
The sequencing of the human genome
Animation of genome sequencing
7
Some current and potential applications of genome
research include

• Molecular medicine
• Energy sources and environmental applications
• Risk assessment
• Bioarchaeology, anthropology, evolution, and
  human migration
• DNA forensics (identification)
• Agriculture, livestock breeding, and
  bioprocessing

Detail of each bullet point
8
(No Transcript)