Lateral view of a zebrafish embryo

Confocal micrograph of a transgenic zebrafish embryo. Some neurons in the brain are highlighted in green due to the presence of green fluorescent protein (GFP). GFP is expressed under the control of a specific promoter Dlx4/6. The DLX proteins are postulated to play a role in forebrain and facial development. Therefore, the GFP is only 'switched on' in developing neurons that require this gene. Neuronal processes have been labelled using an antibody for tubulin (red), which is important for microtubule formation. The image is a lateral (side) view of the embryo showing the head region. The large circular structure is the eye, showing the structure of the retina.