Codes and enigmas

Abstract

“The biggest obstacle after the sequencing of the genome has been to understand how genes are regulated and how we can see that from the sequence,” says Jussi Taipale, who studies gene regulation at the University of Helsinki, Finland. “It’s a more complex code than the genetic code.” The first difficulty is the sheer scale of the problem. Human cells contain more than 20,000 protein-coding genes, roughly 1,500–2,000 transcription factors, which switch genes on and off, and numerous other regulatory proteins and RNAs that direct their production. The possible permutations and combinations are bewildering.