8-cell embryos of the crustacean, Parhyale hawaiensis, injected with FITC-Dextran.  In the right three embryos, the injected cell is the "g" micromere (which gives rise to the germline), and in the left embryo, the injected cell is the "Mav" macromere (which gives rise to the visceral mesoderm and somatic mesoderm of the head).

Blastoderm stage Drosophila melanogaster embryo immunostained for Fushi tarazu (red), Even-skipped (purple), and Snail (green).  Nuclei are stained with DAPI (blue).  Lateral view, anterior to left, ventral down.

Embryonic development of the plant, Arabidopsis thaliana from heart stage (left) through torpedo stage (right).  The expression pattern of the transcription factor KAN2 (green) defines the abaxial/peripheral domain of the embryo and shoot.

Skeleton preparation of a stickleback fish.  Stained with Alizarin red and imaged by fluorescence microscopy.

Embryonic day 18.5 mouse ovary section.  The germ cells (oocytes) in blue are stained with SCP3, all nuclei are stained with syto13 (green), and the vasculature in red is stained with pecam.

This Pacific Chorus Frog (Pseudacris regilla) from a California pond was the victim of an attack by the infecting stage of a parasitic flatworm (Trematode, species Ribeiroia ondatrae).  The limb deformities (shown by Alcian blue/Alizarin red staining) are the result of an adaptive parasite host-modification.  Learn more about how trematodes cause limb deformities here and here.

Two male specimens of the African butterfly, Precis octavia sesamus, displaying a remarkable example of polyphenism.  The left specimen is the summer form, the right specimen is the winter form.  The variation in color is dependent on the temperature at which larvae and pupae are raised.