Millions of new cells are being made in your body as you read this sentence. Scientists measure the cell cycle from the point of birth to the point at which a cell divides again. There are many checks and balances that ensure smooth progression through the cycle. Accidents will happen, however, and cancer ensues when the balance goes askew. Cells divide uncontrollably to form tumours. This can occur when some proteins block the production of others, interrupting the cell cycle. Under the microscope this fruit fly larvae wing has been dyed (green) to reveal posterior sex combs (PSC), a protein that can block the cell cycle. Somehow it hampers the production of cyclin B, one of the key ‘managers’ of this cycle. Scientists here try to decipher at which stage the blockage is implemented. Blockage must occur after the signal to make cyclin B (red line).
Written by Andrew Purcell
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences (the new name for the MRC Clinical Sciences Centre) the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.