Dynamic localisation of KR-H during an ecdysone response in Drosophila
Section snippets
KR-H expression is ubiquitous at the onset of metamorphosis
In situ transcript analyses revealed Kr-h expression to be restricted to the nervous system during embryogenesis (Beck et al., 2004) while RT-PCR analyses showed expression in all tissues tested at pupariation (Pecasse et al., 2000). Antibody studies of embryos confirmed that KR-H was restricted to neurones. We therefore undertook a study of KR-H localisation in late larval and prepupal tissues making a series of preparations from the second half of the third larval instar until the mid
Localisation and levels of KR-H in early metamorphosis
The present study completes our analysis of Kr-h transcripts and proteins during embryogenesis and early metamorphosis and confirms that the KR-H proteins follow the Kr-h transcript pattern. Thus it appears that Kr-h regulation is mainly at the level of transcription although with our current antibody we cannot exclude that KR-H may be subject to post-translational modifications. The protein is localised essentially in the nucleus, which is consistent with the presence of eight zinc fingers and
Stocks and staging
The Oregon-R wild type strain was maintained at 25 °C on a standard agar medium. In our conditions the majority of the animals leave the food between 110 and 114 h after egg laying (110 h larvae). Wandering larvae are selected higher up the culture tube during the ecdysone response (as visualised by puffing patterns). This phase lasts between 6 and 8 h with pupariation centred on 120 h. For prepupal staging, animals are selected as white prepupae (±15 min) and aged on damp filter paper at 25 °C.
Immunocytochemistry
The
Acknowledgements
We thank the IGBMC core facilities for confocal microscopy and antibody production. We thank the reviewer who suggested that a problem of antibody penetration might exist in late larval glands. This work was supported by institutional funds from the Centre National de la Recherche Scientifique, the Institut National de la Santé et de la Recherche Médicale, the Hôpital Universitaire de Strasbourg and studentships from the Ministère de la Recherche et de la Technologie and the Association pour la
References (20)
- et al.
The Drosophila E93 gene from the 93F early puff displays stage- and tissue-specific regulation by 20-hydroxyecdysone
Dev. Biol.
(1995) - et al.
Krüppel-homolog is essential for the coordination of regulatory gene hierarchies in early Drosophila development
Dev. Biol.
(2004) - et al.
Isolation and characterization of novel mutations of the Broad-Complex, a key regulatory gene of ecdysone induction in Drosophila melanogaster
Insect Biochem. Mol. Biol.
(2002) - et al.
The reaction with polytene chromosomes of antibodies raised against Drosophila E75A protein
Insect Biochem. Mol. Biol.
(1993) - et al.
E93 directs steroid-triggered programmed cell death in Drosophila
Mol. Cell
(2000) - et al.
Krüppel-homolog, a stage-specific modulator of the prepupal ecdysone response, is essential for Drosophila metamorphosis
Dev. Biol.
(2000) The ecdysone regulatory cascade in Drosophila
Adv. Dev. Biol.
(1997)Files on steroids—Drosophila metamorphosis and the mechanisms of steroid hormone action
Trends Genet.
(1996)- et al.
Molecular interactions within the ecdysone regulatory hierarchy: DNA binding properties of the Drosophila ecdysone-inducible E74A protein
Cell
(1990) Puffing patterns in Drosophila melanogaster and related species
Cited by (12)
The juvenile hormone receptor and molecular mechanisms of juvenile hormone action
2014, Advances in Insect PhysiologyCitation Excerpt :The mechanisms underlying Kr-h1-dependent suppression of larval Broad and activation of pupal Broad are unknown. However, Kr-h1 localizes to the nucleus of larval tissues in Drosophila and binds to early gene loci in salivary gland polytene chromosomes (Beck et al., 2005), suggesting that Kr-h1 may act through direct binding to DNA. Although the role of JH in regulating the metamorphosis of Drosophila differs from that of Tribolium, the pathway involving JH, Met, Kr-h1 and Broad is preserved.
Evolution of Nuclear Receptors in Insects
2012, Insect EndocrinologyEvolution of Nuclear Receptors in Insects
2011, Insect EndocrinologyThe buzz on fly neuronal remodeling
2008, Trends in Endocrinology and MetabolismCitation Excerpt :Extensive work has shown that a small set of transcription factors are directly induced by ecdysone (primary-response genes) to regulate expression of many secondary-response genes that coordinate appropriate cellular responses to the hormone [49,50]. Interestingly, Kr-h11 mutant prepupae display altered expression of several ecdysone primary-response genes, including E74A, E74B, E75B, E93 and transcripts encoding two isoforms of the ecdysone receptor, EcR-B1 and EcR-B2 [29,46]. Kr-h1 is itself upregulated by ecdysone by approximately fivefold in cultured salivary glands from wild-type larvae [29].
Juvenile hormone action: A 2007 perspective
2008, Journal of Insect PhysiologyAnnotation of Tribolium nuclear receptors reveals an increase in evolutionary rate of a network controlling the ecdysone cascade
2008, Insect Biochemistry and Molecular BiologyCitation Excerpt :Our results show that these genes did not experienced the Mecopterida “overacceleration.” One exception is Kr-h1, an ecdysone-regulated gene encoding a zinc-finger protein, which modulates the prepupal response (Pecasse et al., 2000; Beck et al., 2005). Unfortunately, nothing is known about its possible contacts with other key proteins of the ecdysone pathway.