Investigating giant (Gt) repression in the formation of partially overlapping pair‐rule stripes

Abstract

Drosophila pair-rule genes are expressed in striped patterns with a precise order of overlap between stripes of different genes. We investigated the role of Giant (Gt) in the regulation of even-skipped, hairy, runt, and fushi tarazu stripes formed in the vicinity of Gt expression domains. In gt null embryos, specific stripes of eve, h, run, and ftz are disrupted. With an ectopic expression system, we verified that stripes affected in the mutant are also repressed. Simultaneously hybridizing gt misxpressing embryos with two pair-rule gene probes, we were able to distinguish differences in the repression of pairs of stripes that overlap extensively. Together, our results showed Gt repression roles in the regulation of two groups of partially overlapping stripes and that Gt morphogen activity is part of the mechanism responsible for the differential positioning of these stripes borders. We discuss the possibility that other factors regulate Gt stripe targets as well. Developmental Dynamics 239:2989-2999,

Toward new Drosophila paradigms

“…This interpretation can be biased because all these cases are related to Hox genes. However, members of other families of transcription factors such as otd , Krüppel ( Kr ), and tailless ( tll ) are involved in conserved aspects of nervous system development throughout metazoans, and their segmentation roles might be restricted to arthropods or to some groups of arthropods (Gui et al ., 2011; Janssen et al ., 2011; Ranade et al ., 2008).…”