Developmental changes in the responsiveness to ecdysterone of chromosome region I-18C of Chironomus tentans

Lezzi, Markus; Gatzka, Friederike; Robert‐Nicoud, Michel

doi:10.1007/bf00293331

Cited by 8 publications

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

Immunological studies on the developmental and chromosomal distribution of ecdysteroid receptor protein in Chironomus tentans

Wegmann

Quack

Spindler

et al. 1995

Arch Insect Biochem Physiol

Self Cite

View full text Add to dashboard Cite

Antisera were raised against different domains of a putative ecdysteroid receptor (cEcRH) of Chironomus tentans. All the antisera reacted with a 68,000 dalton protein exhibiting DNA binding properties. Additionally, we were able to demonstrate that the antisera immunoprecipitate protein which binds a radioactively labeled ecdysteroid (Ec), i.e., [3H]ponasterone A, with high specificity. These properties indicate that the antisera recognize specifically an endogenous ecdysteroid receptor protein (cEcR) in C. tentans cells and thus are suitable for the following quantitative and qualitative immunological and immunohistochemical investigations. The cellular level of cEcR varies during development, and it is particularly low in oligopausing larvae. In polytene chromosomes of prepupal salivary glands, cEcR is located at approximately 50 transcriptionally active loci. These loci include both early ecdysteroid (Ec)-inducible puff sites, such as the locus containing the gene coding for the homolog of the E75 protein in Drosophila melanogaster, as well as late Ec-inducible puff-sites. The latter group comprises a locus of a gene specifying the homolog of the D. melanogaster ultraspiracle protein. However, loci of genes coding for salivary gland secretory proteins (e.g., Balbiani ring forming chromosome regions) do not specifically react with the antisera. Thus, the developmental regulation of these genes is not directly controlled by Ec. Polytene chromosomes of oligopausing larvae show hardly any loci that contain cEcR. The few detected correspond, with few exceptions, to the most potent cEcR binding sites found in prepupae.

show abstract

Immunological studies on the developmental and chromosomal distribution of ecdysteroid receptor protein in Chironomus tentans

Wegmann

Quack

Spindler

et al. 1995

Arch Insect Biochem Physiol

Self Cite

View full text Add to dashboard Cite

show abstract

Ecdysteroid binding sites localized by autoradiography in the central nervous system of precommitment fifth-stadium Manduca sexta larvae

1991

View full text Add to dashboard Cite

Brains and subesophageal ganglia from day 3.5 fifth stadium larvae of Manduca sexta were incubated in vitro with 4 nM tritiated ponasterone A, a 20-hydroxyecdysone analog, to determine whether uptake and specific binding of ecdysteroids occur at a cellular level. These tissues, which were taken just prior to the commitment peak in the hemolymph-ecdysteroid titer, showed saturable uptake of 3H-ponasterone A after 40-60 min of incubation. Uptake was blocked by the addition of 400 nM unlabelled ponasterone A, or of 500 nM or 1000 nM 20-hydroxyecdysone. RH 5849, a synthetic 20-hydroxyecdysone agonist with a long half-life, for which ecdysteroid receptors have low affinity, also reduced ponasterone A uptake at a concentration of 10 microM. Autoradiographs of 4 microns sections of brains revealed distinct nuclear concentrations of silver grains over cell populations in the pars intercerebralis, pars lateralis, and ventral tritocerebrum. Nuclear labelling was also found in many small cells around the mushroom bodies and the neuropil, and between the inner and outer larval optic lobes. Nuclear labelling of cells in the subesophageal ganglion was observed in the fronto-medial and lateral regions, in small cells around the neuropil, and caudally in a few large neurons. In addition to cells with nuclear labelling, both brains and ganglia at this development stage contained cells with exclusively cytoplasmic or both nuclear and cytoplasmic labelling. None of these apparent binding sites were observed in the competition experiments, suggesting that the binding is specific.

show abstract

Transcriptional activation of puff site I-18C of Chironomus tentans: Hormonal responsiveness changes in parallel with diurnal decondensation cycle

et al. 1991

View full text Add to dashboard Cite

Developmental changes in the responsiveness to ecdysterone of chromosome region I-18C of Chironomus tentans

Cited by 8 publications

References 28 publications

Immunological studies on the developmental and chromosomal distribution of ecdysteroid receptor protein in Chironomus tentans

Immunological studies on the developmental and chromosomal distribution of ecdysteroid receptor protein in Chironomus tentans

Ecdysteroid binding sites localized by autoradiography in the central nervous system of precommitment fifth-stadium Manduca sexta larvae

Transcriptional activation of puff site I-18C of Chironomus tentans: Hormonal responsiveness changes in parallel with diurnal decondensation cycle

Contact Info

Product

Resources

About