Interactions of the Drosophila gap gene giant with maternal and zygotic pattern-forming genes

摘要: The Drosophila gene giant (gt) is a segmentation that affects anterior head structures and abdominal segments A5-A7. Immunolocalization of the gt product shows it nuclear protein whose expression initially activated in an posterior domain. Activation domain dependent on maternal bicoid gradient while activation requires nanos product. Initial not abolished by mutations any zygotic gap genes. By cellular blastoderm, initial pattern has evolved into one three stripes expression. evolution, position width these are interactions between other In turn, activity domains These interactions, typical cross-regulation previously observed among genes, confirm member class function necessary to establish overall After continues be expressed region parts maxillary mandibular as well labrum. Expression never detected labial or thoracic segment primordia but persists certain structures, including ring gland, until end embryonic development.