2. Central Dogma
⇨ genes --> proteins --> function
● genes do not act in isolation
● interaction of multiple genes results in a particular
behaviour in the organism
● require high-throughput and scalable technology to
observe genes simultaneously
3. Gene Expression
⇨ Process by which information from a gene is
used to synthesize functional product (protein,
mRNA, etc) ~ ‘manifestation’ of the gene
⇨ The pattern of gene expression characterises
current state of the cells
4. Microarray
⇨ Microarrays measure expression level of
thousands of genes simultaneously
⇨ Applications of Microarray technology
● Identification of complex genetic diseases
● Drug discovery
● Comparative studies between diseased/normal tissue
5. Microarray Design
⇨ Thousands of 'spots' on a single substrate
● each spot contains a complementary strand of DNA,
which uniquely identifies the gene (probe)
● substrate washed with fluorescently labelled sample
(target)
● Normal tissue green, Diseased Tissue red
● complementary sequences bind to the spots
● the resulting fluorescence at each spot is a measure of
the expression level of the corresponding gene
14. Beyond Numerical Analysis
⇨ Use numerical results along with known
biological information to make intelligent
conjectures
⇨ Annotate genes to obtain functional info
⇨ Text mining on function, literature (ex. PubMed)
● which genes have similar function ?
● which genes are part of the same pathway ?
● which genes are referred together in literature ?