Pattern formation by interaction of three cytoplasmic factors in the egg of the leafhopper Euscelis plebejus

Developmental capacities of different parts of the Euscelis plebejus egg were tested by translocating posterior pole material and subsequent transverse constriction of the egg posterior to the translocated material. The results support the hypothesis that at least three cytoplasmic factors of maternal origin are necessary to form a complete germ band. Those factors do not act autonomously. The anterior and posterior factors require interaction with the middle factor in order to cause formation of head and abdomen, respectively. The middle factor, on the other hand, forms a complete thorax only if it is in contact with the posterior factor.