The fruit fly Drosophila is a model organism frequently used in cell and developmental biology in order to understand the biology of other organisms, such as humans.  A recent paper describes important findings in fruit fly stem cells that give the stem cell research community a great boost.  

If there is hope to fully understand stem cells, then the environment surrounding those stem cells must be understood too.  The microenvironment around a stem cell is called its “niche” and plays an important role in regulating stem cell self-renewal and differentiation.  For example, the fruit fly testes have germ line stem cells that are important for producing sperm throughout adulthood.  These stem cells cluster around its niche, called the “hub.”  A recent study found how certain cells become specified to become niche hub cells.  Specifically, this process requires Notch, a signaling protein used in many developmental processes, as well as two Notch activators called Delta and Serrate.  As seen in the above images of developing fly gonads, flies with mutations in Delta (left, bottom) or Serrate (right, bottom) have fewer hub cells (green) than control experiments (top).

For a more scientifically detailed description of this image, check out my post on The Node, the community forum for and by developmental biologists.