How on earth, you might ask, can the hairs on the backs of fruit flies (pictured), teach scientists about cancer? Well, it’s all to do with asymmetric cell division. As a person (or fly) develops from a single fertilised egg, the initial cell divisions are symmetrical, but later asymmetrical divisions become important for establishing the different tissues of the body. Indeed, the hairs on flies’ backs are a perfect example, because they form only if the underlying cells divide in the correct asymmetrical manner. In the normal fly (left) asymmetric cell divisions are as they should be, but the bald-backed fly (right) has a mutation causing the asymmetry to be lost and hair development to fail. Cancer sometimes initiates when the normal asymmetric divisions of stem cells become symmetrical – leading to self-renewal without differentiation. Learning how flies’ hair cells divide, could therefore also provide clues to how cancer kicks off.
Written by Ruth Williams
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences 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.