Dr Andrew Gillis shows us an embryonic skate head and explains how the red denticles dotted all over it have very similar properties to human teeth.

Dr Gillis:
"This is a picture of the head of an embryonic skate (Leucoraja erinacea). A skate is a cartilaginous fish, closely related to sharks and stingrays. This embryo has been stained with dyes that colour the skeleton - cartilage is blue, and mineralised tissue is red - and then cleared with chemicals to make it transparent. The result is a specimen that shows the complex shape and arrangement of different skeletal tissues during embryonic development. I use this staining procedure to visualise the skeleton following experimental manipulation. This allows me to investigate how different genes and proteins are involved in controlling the formation and growth of different skeletal tissues in these fishes".

The skate image is approximately 3cm across.

More info:
http://www.pdn.cam.ac.uk/~jag93

Music by Peter Nickalls:
http://www.peternickalls.com

With thanks:
Graduate School of Life Sciences and its annual Poster and Image Competitions
http://www.biomed.cam.ac.uk/gradschool/comp/2011/index.html