IMISE Goals of today: Find out which genes are differentially expressed between human and chimpanzee brains • Using microarrays (Affymetrix arrays) • Using RNA-Seq (Illumina sequencing) • Measure RNA levels for all or at least thousands of genes at a time for each sample • " Snapshot " approach Each cell has a unique set of thousands of different RNAs A piece of tissue typically consists of different cell types Gene expression: mRNA = messenger RNA protein ncRNAs = non-coding RNAs active as RNAs All these different RNA " species " are measured by RNA-Seq