January 2010 Contest Picture #3

Greg Reeves's 'Untitled'

Graded concentrations of signaling factors contribute to patterning during development. We used confocal imaging to measure the Dorsal nuclear gradient (green) as well as sog mRNA (a Dorsal target gene, blue) in a fruit fly embryo (nuclei in red). The overlaid graph shows the measured Dorsal nuclear gradient and sog pattern along the dorsal-ventral axis, suggesting that Dorsal alone cannot account for observed patterning.