One of the most intriguing features of animal development is the formation of body parts that are proportional to the overall size of an individuals body.Such proportionality,or scaling,is an indication of the robustness of the developmental process.It depends on both coordinated tissue growth in the animal and formation of scaled patterns in the embryo.Recent studies suggested that scaled embryonic patterning along the anterior-posterior (AP) axis that is instructed by the Bcd morphogen gradient in Drosophila is controlled maternally.