Cis-regulation and genome architecture during development, evolution and genetic diseases

That's the title of today's PRBB-CRG conference by José Luís Gómez-Skamerta. I learned many things, but here’s two interesting ones:

1-3C (Chromosome Conformation Capture), a high-throughput molecular biology technique used to analyze the organization of chromosomes in a cell. In particular, it allows one to check whether two very distant DNA regions interact with each other via cross-linking, digestion and re-ligation. I had heard about it before, but had forgotten, and it’s quite cool, isn´t it?

2-How the 3D structure of the genome (and particularly, the formation of loops on the DNA) can add a new level of complexity to gene regulation. Gómez-Skamerta showed us how the same collection of genes and the same collection of enhancers can have a very different result through evolution (in different organisms) and through development (at different stages), and one way of achieving this is via the DNA loops. How? Using the example of the Iroquois genes (Irx), which he originally cloned, he showed how keeping two promoters (and several enhancers) within one same loop facilitated the fact that these two genes are activated by the same enhancers. It also explains why those enhancers in the loop have more difficulty to activate a gene outside the loop.

And that’s my very brief summary :)