A member of the steroid hormone receptor gene family is expressed in the 20-OH-ecdysone inducible puff 75B in<i>Drosophila melanogaster</i>

Feigl, G.; Gram, Magnus; Pongs, Olaf

doi:10.1093/nar/17.18.7167

Cited by 69 publications

(19 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, we predict that the multiple transcripts encoded by the BR-C and E75 will be expressed in a temporal pattern determined by the lengths of their transcription units and the ecdysone concentrations required for their activation and repression. Consistent with this, both of these early genes contain nested promoters spanning unusually long transcribed regions, up to 100 kb in length (Chao and Guild 1986;Feigl et al 1989;Galcerfin et al 1990;Segraves and Hogness 1990;Thummel 1990). As with E74, the E75 transcripts have distinct temporal responses to a high concentration of ecdysone.…”

Section: Future Considerationsmentioning

confidence: 72%

“…As with E74, E75 is an unusually complex gene, spanning >50 kb and composed of several nested transcriptiGn units. E75 encodes at least three related proteins, all of which are members of the steroid hormone receptor superfamily (Feigl et al 1989;Segraves and Hogness 1990). We predict that each of the E75 transcripts is activated at different ecdysone concentrations spanning the broad range required for 75B puff formation.…”

Section: Both E74a and E74b Contribute To 74ef Puff Formationmentioning

confidence: 99%

See 1 more Smart Citation

Ecdysone coordinates the timing and amounts of E74A and E74B transcription in Drosophila.

Karim¹,

Thummel²

1991

Genes Dev.

143

100

View full text Add to dashboard Cite

Pulses of the steroid hormone ecdysone function as temporal signals to coordinate the development of both larval and adult tissues in Drosophila. Ecdysone acts by triggering a genetic regulatory hierarchy that can be visualized as puffs in the larval polytene chromosomes. In an effort to understand how the ecdysone signal is transduced to result in sequential gene activation, we are studying the transcriptional control of E74, an early gene that appears to play a regulatory role in the hierarchy. Northern blot analysis of RNA isolated from staged animals or cultured organs was used to characterize the effects of ecdysone on E74 transcription. Ecdysone directly activates both E74A and E74B promoters. E74B mRNA precedes that of E74A, each mRNA appearing with delay times that agree with their primary transcript lengths and our previous transcription elongation rate measurement of -1.1 kb/min. The earlier appearance of E74B transcripts is enhanced by its activation at an -25-fold lower ecdysone concentration than E74A. E74B is further distinguished from E74A by its repression at a significantly higher ecdysone concentration than that required for its induction, close to the concentration required for E74A activation. These regulatory properties lead to an ecdysone-induced switch in E74 expression, with an initial burst of E74B transcription followed by a burst of E74A transcription. We also show that the patterns of ecdysone-induced E74A and E74B transcription vary in four ecdysone target tissues. These studies provide a means to translate the profile of a hormone pulse into different amounts and times of regulatory gene expression that, in turn, could direct different developmental responses in a temporally and spatially regulated manner.[Key Words: Ecdysone; transcription; metamorphosis; Drosophila; timing; steroid hormones] Received January 16, 1991; revised version accepted March 15, 1991.Steroid hormones provide higher organisms with a systemic signaling system that coordinates the growth and development of different tissues. In the fruit fly, Drosophila melanogaster, this function is provided by the steroid hormone 20-hydroxyecdysone (henceforth referred to as ecdysone), which acts throughout the life cycle to synchronize tissue-specific developmental changes (Richards 1981a). Pulses of ecdysone are released into the hemolymph during each of the six developmental stages of Drosophila: (1) in the middle of embryogenesis, (2,3) preceding the first and second-instar larval molts, (4) at the beginning of metamorphosis in late third-instar larvae, (5)preceding head eversion in prepupae, and (6) during pupal development (Richards 1981b). The most extensively studied pulse of ecdysone, at the onset of metamorphosis, serves as a temporal cue to synchronize a complex pattern of behavioral, genetic, and morphological changes that culminates in the formation of the adult fly. In triggering metamorphosis, ecdysone activates two divergent developmental pathways: The larval tissues are histolyzed, having served their functi...

show abstract

Section: Future Considerationsmentioning

confidence: 72%

Section: Both E74a and E74b Contribute To 74ef Puff Formationmentioning

confidence: 99%

Ecdysone coordinates the timing and amounts of E74A and E74B transcription in Drosophila.

Karim¹,

Thummel²

1991

Genes Dev.

143

100

View full text Add to dashboard Cite

show abstract

“…GM04985 hybridizes to the posterior follicle cells during stages 6-9. Sequence from the 5-Ј end [Berkeley Drosophila Genome Project(BDGP)͞Howard Hughes Medical Institute EST Project, unpublished data] shows that the clone is a novel splice variant of the ecdysone-inducible nuclear hormone receptor superfamily gene E75 (29,30), in which a unique region (base pairs 1-344 of the BDGP sequence) is spliced into the exon 2͞3 junction of the E75A͞B common region (31). We have sequenced the remainder of the clone, and found it to match the common exons 3, 4, and 5 of E75A͞B, with a poly(A) region beginning at base pair 4574 of the E75A sequence.…”

Section: Resultsmentioning

confidence: 99%

Characterization of differentially expressed genes in purified Drosophila follicle cells: Toward a general strategy for cell type-specific developmental analysis

Bryant

Subrahmanyan

Tworoger

et al. 1999

Proc. Natl. Acad. Sci. U.S.A.

105

View full text Add to dashboard Cite

Axis formation in Drosophila depends on correct patterning of the follicular epithelium and on signaling between the germ line and soma during oogenesis. We describe a method for identifying genes expressed in the follicle cells with potential roles in axis formation. Follicle cells are purified from whole ovaries by enzymatic digestion, filtration, and f luorescence-activated cell sorting (FACS). Two strategies are used to obtain complementary cell groups. In the first strategy, spatially restricted subpopulations are marked for FACS selection using a green f luorescent protein (GFP) reporter. In the second, cells are purified from animals mutant for the epidermal growth factor receptor ligand gurken (grk) and from their wild-type siblings. cDNA from these samples of spatially restricted or genetically mutant follicle cells is used in differential expression screens employing PCR-based differential display or hybridization to a cDNA microarray. Positives are confirmed by in situ hybridization to whole mounts. These methods are found to be capable of identifying both spatially restricted and grk-dependent transcripts. Results from our pilot screens include (i) the identification of a homologue of the immunophilin FKBP-12 with dorsal anterior expression in egg chambers, (ii) the discovery that the ecdysone-inducible nuclear hormone receptor gene E78 is regulated by grk during oogenesis and is required for proper dorsal appendage formation, and (iii) the identification of a Drosophila homologue of the human SET-binding factor gene SBF1 with elevated transcription in grk mutant egg chambers.Recent years have seen an explosion in tools for analyzing differential gene expression. The development of a PCR-based differential display method by Liang et al. (1, 2) has quickly been followed by array-based methods for monitoring the expression of thousands of defined genes simultaneously (3, 4). Developmental biology, a field whose progress depends heavily on understanding regulated gene expression, stands to benefit from these methods. However, there are technical hurdles to be overcome before molecular screening methods can be widely applied to problems in development. Chief among these hurdles is purification of the tissue of interest from the complex mixture of cell types typically present in a developing system. Whereas some tissues are amenable to microdissection, others will require more sophisticated techniques such as fluorescence-activated cell sorting (FACS) of dissociated tissue (5-7). The molecular screens reported herein rely on a FACS-based approach to purify specialized follicle cells from Drosophila ovaries. The system we have chosen is particularly illustrative of the need for tissue purification: the Drosophila ovary is composed of egg chambers in which a cyst of large germ-line cells is surrounded by a thin epithelium of highly differentiated follicle cells. Patterning of subregions of the follicular epithelium involves intermingled cell groups, each comprising only a tiny fraction of the volume...

show abstract

“…The Drosophila gene E75 encodes at least three transcripts designated A, B and C that arise from alternate promoters and differ in their 5' exons [5,6,81. Forms A and C encode both zinc fingers of the DNA-binding domain, whereas E75 B has a unique 5' exon and lacks the N-terminal zinc finger.…”

Section: Gme75 Isoformsmentioning

confidence: 99%

Isolation, characterization and developmental expression of the ecdysteroid‐induced E75 gene of the wax moth Galleria mellonella

Jindra

Sehnal

Riddiford

1994

European Journal of Biochemistry

View full text Add to dashboard Cite

Using the cDNA for the Drosophila ecdysteroid-induced member of the steroid-hormone-receptor superfamily, E75A, we isolated a genomic clone from Galleria mellonella that revealed 77% similarity with the region of E75A cDNA encoding the C-terminal zinc-finger motif. A Galleria cDNA clone was isolated that encoded a complete DNA-binding domain composed of two zinc fingers and designated GmE75A. Its deduced amino acid sequence showed 100% and 85% identities within the DNA-binding and ligand-binding domains of Drosophila E75 A, respectively. The Galleria genomic clone did not encode the N-terminal zinc finger, but included a sequence similar to the B1 exon, which is unique to the B isoform of E75. Thus, the cDNA and genomic DNA sequences indicated that the Galleria gene E75 encoded at least two isoforms, GmE75 A and GmE75 B, which differed in their N-termini.Probes specific for GmE75A and B hybridized to two distinct transcripts of 2.6 kb. Both GmE75A and B mRNA levels correlated closely with the ecdysteroid titer during development. At the onset of larval/pupal transformation, both transcripts appeared in high amounts within 4 h of the ecdysteroid rise, then declined concurrently with the hormone titer decline. At the time of pupal ecdysis, there was another peak of GmE75 A expression but not GmE75B expression, coincident with a minor ecdysteroid pulse. In isolated abdomens of final instar larvae, GmE75A mRNA was induced by 20-hydroxyecdysone within 20 min of the injection; the mRNA levels were maximal at 1 h and declined by 3 h following the treatment.Post-embryonic development in insects is a cyclical process punctuated by alternation of molts and intermolt periods followed by metamorphosis. The molts are initiated and coordinated by the steroid hormone 20-hydroxyecdysone (20E) and related ecdysteroids [l]. The intermolt growth periods are characterized by a low ecdysteroid titer, which increases dramatically at the time of the molt. During the last larval instar, low levels of ecdysteroid in the absence of juvenile hormone, a sesquiterpenoid, initiate metamorphosis by causing pupal commitment of tissues. Then, a higher ecdysteroid level triggers a pupal molt.From studies of the effects of 20E on the 'puffing patterns' of the giant polytene chromosomes of Drosophila melanogaster, Ashburner et al. [2] proposed a model for ecdysteroid action. In this model, the ecdysteroid combined with its receptor binds to the target DNA to induce directly the 'early puff' genes and to repress the 'late puff' genes. The protein products encoded by the early genes then activate the late genes while inhibiting their own synthesis. In support ofCorrespondence to M. Jindra, Department of Zoology NJ-15, Fax: +1 206 543 3041.

show abstract

A member of the steroid hormone receptor gene family is expressed in the 20-OH-ecdysone inducible puff 75B inDrosophila melanogaster

Cited by 69 publications

References 35 publications

Ecdysone coordinates the timing and amounts of E74A and E74B transcription in Drosophila.

Ecdysone coordinates the timing and amounts of E74A and E74B transcription in Drosophila.

Characterization of differentially expressed genes in purified Drosophila follicle cells: Toward a general strategy for cell type-specific developmental analysis

Isolation, characterization and developmental expression of the ecdysteroid‐induced E75 gene of the wax moth Galleria mellonella

Contact Info

Product

Resources

About