title: Control of the initiation of homeotic gene expression by the gap genes giant and tailless in Drosophila.
abstract: The process of segmentation in Drosophila is controlled by both maternal and zygotic genes. Members of the gap class of segmentation genes play a key role in this process by interpreting maternal information and controlling the expression of pair-rule and homeotic genes. We have analyzed the pattern of expression of a variety of homeotic, pair-rule, and gap genes in tailless and giant gap mutants. tailless acts in two domains, one anterodorsal and one posterior. In its anterior domain tailless exerts a repressive effect on the expression of fushi tarazu, hunchback, and Deformed. In its posterior domain of action, tailless is responsible for the establishment of Abdominal-B expression and demarcating the posterior boundary of the initial domain of expression of Ultrabithorax. giant is an early zygotic regulator of the gap gene hunchback: in giant- embryos, alterations in the anterior domain of hunchback expression are visible by the beginning of cycle 14. giant also regulates the establishment of the expression patterns of Antennapedia and Abdominal-B. In particular, giant is the factor that controls the anterior limit of early Antennapedia expression.
authors.affiliation: Department of Biological Sciences, Fairchild Center, Columbia University, New York, New York 10027.
authors.forename: J
authors.initials: J
authors.lastname: Reinitz
authors.forename: M
authors.initials: M
authors.lastname: Levine
mesh_terms: D000818:Animals; D002970:Cleavage Stage, Ovum / Q000502:physiology; D015342:DNA Probes; D004330:Drosophila / Q000196:embryology / Q000235:genetics*; D005786:Gene Expression Regulation; D005801:Genes, Homeobox; D005809:Genes, Regulator / Q000502:physiology*; D008853:Microscopy; D014158:Transcription, Genetic
chemical_list: D015342:DNA Probes