Developmental biology: A chordate with a difference.

The article focuses on a molecular study of the life cycle of tunicate. The genetic programs for patterning the early embryonic cycle are found to reveal a radical change during the development without complete disturbance of basic chordate body plan. However, while fundamental chordate body plan has retained, mechanism of retinoic-acid signaling that operates during such development has been lost. Such loss has prevented similar changes in other chordates.