Scientists find signals that make cell nucleus blow up like a balloon

Video: Frog puppets explain the research in this piece by Professor Rebecca Heald and post-doc Daniel Levy. BERKELEY — Size matters when it comes to the nucleus of a cell, and now scientists have discovered the signals that control how big the nucleus gets. Nuclear size varies not only among different species, but also in different types of cells in the same species and at different times during development. In addition, cancer cells are known to develop larger nuclei as they become more malignant. Screening for cervical cancer, for example, involves looking for grossly distorted nuclei in cervical cells collected during a Pap smear. In the researchers' analogy, larger frogs blow more structural material into the nucleus (thanks to the carrier protein importin-α), allowing the nuclear bubble to grow bigger than that of smaller frogs. The black squiggly inside each bubble represents DNA.