Like all life, this mouse embryo is a result of the blueprint that lies in its DNA. But unlike normal mice, it’s also a literal print in blue of one part of this genetic building plan: the dark spots show where a specific ‘regulatory element’ of the DNA was active. These elements turn gene activity up or down, influencing how much protein is made. This way all the right parts of the body are built in all the right places. You can’t normally see regulatory elements at work, so scientists have done something special here to make the blue spots appear. They hooked up the regulatory element to a bacterial gene whose product turns an added chemical blue. Armed with this technique researchers are delving further into how DNA blueprints build bodies, and where things go wrong in developmental diseases.
Written by Emma Bornebroek