Effects of ecdysterone in polytene chromosomes of Trichosia pubescens

Amabis, Dulce Cabral; Amabis, J M

doi:10.1016/0012-1606(84)90169-6

Cited by 28 publications

(10 citation statements)

References 12 publications

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“…Amplification and puffing at DNA puff sites is a late effect of the hormone. Changes at these sites are not observed until approximately 10 h after injection of Ec into feeding larvae of the preamplification stage (Stocker and Pavan 1974;Fresquez 1979;Amabis and Amabis 1984a). DNA amplification and puffing also require RNA (Berendes and Lara 1975) and protein (Amabis and Amabis 1984a) synthesis, since both can be blocked by actinomycin D or cycloheximide.…”

Section: Introductionmentioning

confidence: 93%

“…Primary Ec-dependent RNA puffs have been characterized in Trichosia by Amabis and Amabis (1984a) as small RNA puffs that occur with little delay after Ec injection into young larvae and are not inhibited by cycloheximide. Since we would expect AScE/D signal at these puffs in L3, i.e., during an early stage of Ec release, we first analyzed L3 larvae by choosing puffs that were easiest to identify (Fig.…”

Section: Asce/d Reaction At Primary Ec-inducible Rna Puff Sitesmentioning

confidence: 99%

“…At DNA puff sites, there is both gene-specific amplification and transcription (reviewed in Lara et al 1991). The DNA synthesis, amplification and puffing changes that occur during this final cycle are under the control of the insect moulting hormone, ecdysone (Ec; Crouse 1968;Stocker and Pavan 1974;Amabis and Amabis 1984a). Amplification and puffing at DNA puff sites is a late effect of the hormone.…”

Section: Introductionmentioning

confidence: 99%

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Antibodies against the D-domain of a Chironomus ecdysone receptor protein react with DNA puff sites in Trichosia pubescens

et al. 1997

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An antiserum (called AScE/D) against the semiconserved D-domain of a Chironomus tentans ecdysone receptor protein (cEcR) gave indirect immunofluorescence signals at DNA puff sites in Trichosia pubescens. The signals varied in maximum intensity at different DNA puff sites. Control experiments using the secondary rhodamine-labeled anti-rabbit IgG alone, preimmune serum, affinity purified AScE/D (called pABcE/D) and AScE/D preabsorbed with expressing bacterial extract or highly purified bacterially expressed cEcR indicated that the signals obtained at these chromosomal sites were likely to be due to specific interaction between an endogenous sciarid EcR and antibodies against cEcR. This conclusion was supported by observation of signals at certain Ec-inducible primary RNA puff sites. AScE/D signals began to appear at DNA puff sites during L3, the stage when amplification initiates, but at most sites their mean intensity was low and not statistically significant. Sites with AScE/D signals of significant mean intensity at this stage already showed evidence of transcription. The number and strength of transcription signals increased during L4. Comparison of the developmental course of signals for AScE/D, DNA synthesis, RNA presence/synthesis, and puff size for several DNA puffs during late larval- prepupal development showed a closer relationship of AScE/D signals with the initiation of RNA synthesis than with the initiation of DNA synthesis. Therefore, although we cannot absolutely eliminate a direct involvement of EcR in the amplification process at some sites, this investigation gives stronger support for its direct involvement in transcription. Since AScE/D signals are observed at DNA puff sites from the time the latter begin amplification/transcription through their regression, it appears that Ec and EcR are necessary as a sustained stimulus at these regions.

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Section: Introductionmentioning

confidence: 93%

Section: Asce/d Reaction At Primary Ec-inducible Rna Puff Sitesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Antibodies against the D-domain of a Chironomus ecdysone receptor protein react with DNA puff sites in Trichosia pubescens

et al. 1997

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“…In S. coprophila, there are additional germline-limited 'L' chromosomes (mostly heterochromatic) that are also discarded from the embryo soma by a similar elimination process to that of X p chromosomes (Rieffel and Crouse, 1966;Amabis et al, 1979).…”

Section: Introductionmentioning

confidence: 99%

Histone H3 phosphorylation and elimination of paternal X chromosomes at early cleavages in sciarid flies

Escribá

Goday

2013

Journal of Cell Science

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SummaryIn sciarid flies (Diptera, Sciaridae), one or two paternally derived X chromosomes are discarded from the soma at early cleavages to determine the sex of the embryo (XX, females; X0, males). X chromosome(s) elimination is achieved by an abnormal anaphase segregation so that X sister chromatids do not reach the poles and are not included in the daughter nuclei. A cis-acting locus (CE) within the heterochromatin proximal to the centromere is known to regulate X chromosome elimination. By immunofluorescence analysis in early embryos from Sciara ocellaris and Sciara coprophila, we investigated histone H3 phosphorylation at Ser10, Ser28 and Thr3 prior to, and during, the X elimination process. We found that the regular syncytial nuclear divisions are characterized by a gradual loss of H3S10 phosphorylation along the chromosome arms at anaphase. Importantly, the eliminating X chromosomes show a retardation in anaphase chromatid segregation and high levels of H3S10 phosphorylation in the chromosome arms. In the present study, we provide the first evidence linking the hyper-phosphorylated H3 status of the X chromosome with a delay in sister chromatid separation at anaphase. Our findings support the idea that the CE induces a deficiency in H3 dephosphorylation in the paternal X chromosomes to be eliminated.

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“…The hormone 20-hydroxyecdysone (20E) induces transcription at Drosophila RNA puffs (Ashburner 1972, Ashburner et al 1974) through its interaction with the ecdysone receptor (EcR) and its heterodimeric partner ultraspiracle (USP) (Koelle et al 1991, Yao et al 1992, Talbot et al 1993, Thomas et al 1993. 20E also induces DNA puffs in sciarid larvae (Crouse & Keyl 1968, Stocker & Pavan 1974, Amabis & Amabis 1984a, and EcR/USP binds to DNA puff response elements (EcRE) (Foulk et al 2006). However, the molecular mechanisms of the action of 20E in these processes are still largely unknown de Carvalho et al 2000, Basso et al 2002, Foulk et al 2006.…”

Section: Introductionmentioning

confidence: 97%

Indirect immune detection of ecdysone receptor (EcR) during the formation of DNA puffs in Bradysia hygida (Diptera, Sciaridae)

et al. 2008

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Gene amplification occurs in Bradysia hygida salivary glands, at the end of the fourth larval instar. The hormone 20-hydroxyecdysone (20E) triggers this process, which results in DNA puff formation. Amplified genes are activated in two distinct groups. The activity of the first group is dependent on high levels of 20E, while the second group needs low hormone levels. Consequently, the salivary glands of B. hygida constitute an interesting biological model to study how 20E, and its receptors, affect gene amplification and activity. We produced polyclonal antibodies against B. hygida EcR (BhEcR). In western blots a polypeptide of about 66 kDa was detected in salivary gland extracts. The antibodies were also used for indirect immune-localization of BhEcR in polytene chromosomes. RNA-polymerase II was also immune-detected. We did not detect the receptor in chromosome C where the first and second groups of DNA puffs form during DNA puff anlage formation, but it was present during puff expansion. During the active phase of both groups of DNA puffs, RNA polymerase II co-localized with BhEcR. After puff regression, these antigens were not detected. Apparently, EcR plays a direct role in the transcription of amplified genes, but its role in gene amplification remains enigmatic.

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Effects of ecdysterone in polytene chromosomes of Trichosia pubescens

Cited by 28 publications

References 12 publications

Antibodies against the D-domain of a Chironomus ecdysone receptor protein react with DNA puff sites in Trichosia pubescens

Antibodies against the D-domain of a Chironomus ecdysone receptor protein react with DNA puff sites in Trichosia pubescens

Histone H3 phosphorylation and elimination of paternal X chromosomes at early cleavages in sciarid flies

Indirect immune detection of ecdysone receptor (EcR) during the formation of DNA puffs in Bradysia hygida (Diptera, Sciaridae)

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