Green fluorescent protein (GFP) is expressed in motor neurons in the Drosophila melanogaster larval ventral ganglion. The larva is superimposed on an image of a starry night sky with the North star aligned at the top of the “tree”. The North star stays fixed in the night sky at this time of year, which inspired the tradition of stars on top of evergreen Christmas trees.
Image created by Dr. James Hodge
Image source Griffith lab