Regulation of the EDG84A Gene by FTZ-F1 during Metamorphosis in Drosophila melanogaster

Abstract

The transcription factor FTZ-F1 is a member of the nuclear hormone receptor superfamily and is transiently expressed during the mid-and late prepupal periods in Drosophila melanogaster. A putative pupal cuticle gene, EDG84A, is expressed slightly following FTZ-F1 expression during the prepupal period and carries a strong FTZ-F1 binding site between bases 100 and 92 upstream of its transcription start site. In this study, EDG84A mRNA was found to be prematurely expressed upon heat induction of FTZ-F1 in prepupae carrying the heat shock promoter-FTZ-F1 cDNA fusion gene construct. Transgenic fly lines having the 0.8-kb region of the EDG84A promoter fused to lacZ expressed the reporter gene in a tissue-and stage-specific manner. Base substitutions in the FTZ-F1 binding site within the 0.8-kb promoter abolished expression of lacZ. These results strongly suggest that the EDG84A gene is a direct target of FTZ-F1. Deletion studies of the cis-regulatory region of the EDG84A gene revealed that space-specific expression in imaginal disc-derived epidermis is controlled by the region between bp ؊408 and ؊104 from the transcription start site. The region between bp ؊408 and ؊194 is necessary to repress expression in a posterior part of the body, while the region between bp ؊193 and ؊104 carries a positive element for activation in an anterior part of the body. These results suggest that FTZ-F1 governs expression of the EDG84A gene in conjunction with putative tissue-specific regulators.

Temporal regulation of the mid‐prepupal gene FTZ‐F1: DHR3 early late gene product is one of the plural positive regulators

“…These results indicate that FTZ-F1 is a mid-prepupal gene that is induced by a pulse exposure of 20E. The importance of this stage-specific induction is suggested by the necessity of FTZ-F1 for expression of some late prepupal genes (Woodard et al 1994) and some putative cuticle genes that are expressed in mid-prepupal stage in Drosophila (Murata et al 1996).…”

“…Transgenic fly lines were established as described previously (Murata et al 1996). At least three independent lines were established and expression patterns were confirmed at least in two independent lines.…”

“…Maternally supplied early FTZ-F1 (Guichet et al 1997) activates fushi tarazu in blastoderm embryos . Late FTZ-F1 is present in late embryo, late stage of each larval instar and the mid prepupal stage Lavorgna et al 1993;Murata et al 1996). BmFTZ-F1, a counterpart of FTZ-F1 in the silkworm Bombyx mori, is expressed at the end of each moulting stage (Ueda & Hirose 1990;Sun et al 1994).…”

ftz-f1 and Hr39 opposing roles on EcR expression during Drosophila mushroom body neuron remodeling

“…We therefore localized FTZ-F1 in the second instar larval brain by anti-FTZ-F1 immunostaining 17,26 . FTZ-F1 protein was found to be ubiquitously expressed including in the γ neuron cell bodies which were identified by their expression of GFP under the control of the Fig.…”

A Simple and Quick Method to Isolate Nuclear Extracts from Pupae of Drosophila melanogaster.

“…We have been using Drosophila nuclear extracts to identify factors which regulate gene expression (Murata et al 1996;Kageyama et al 1997). During analyses of gene regulation mechanisms at the onset of metamorphosis, staged nuclear extracts are essential to detect temporally induced factors that are regulated by ecdysteroid hormone.…”