#electron micrograph

Crystal of virus. Magnification : 122, 700X. Electron micrograph. Courtesy Dr. C. Morgan, Department of Microbiology, Columbia University.

This colorized scanning electron micrograph shows the mouth parts of a brown dog tick, one of the most important disease vectors in dogs worldwide. Ticks that carry human pathogens are spreading in the U.S., triggering an increase in tick-borne diseases, including some that are difficult to diagnose and treat.

العصب الشوكي للإنسان، أخذت الصورة بواسطة الميكروغراف الإلكتروني.

Cancer Clues

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

Images from work by Sylvain Loubéry & Alicia Daeden and colleagues

University of Geneva, Geneva, Switzerland

Image originally published under a Creative Commons Licence (BY 4.0)

Published in Nature Communications, June 2017