Ecdysones and Analogs: Effects on Development and Reproduction of Insects

Robbins, W. E.; Kaplanis, J. N.; Thompson, Malcolm J.; Shortino, T. J.; Cohen, Charles F.; Joyner, S. C.

doi:10.1126/science.161.3846.1158

Cited by 122 publications

(42 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Conversely, treatment with the ecdysone receptor antagonist, cucurbitacin B, resulted in a significantly higher number of total offspring relative to controls (MW, n = 15; P = 0.003, day 1; P < 0.001, day 2), and the number of offspring was higher in the EcR dsRNA samples on day 1, although not significantly higher; no differences were seen on day 2 (MW, n = 15; P = 0.118 day 1; P = 0.272 day 2). The feeding of ecdysone or ecdysone analogs inhibits ovarian maturation and egg production in houseflies and other insects (18,32), so this repressive effect on offspring production in the first two experiments is likely mediated by the excess ecdysone, with the opposite effect in the latter two experiments. This expected reproductive effect is an independent indication that the aphids are, in fact, sensing the ecdysone manipulations.…”

Section: Resultsmentioning

confidence: 99%

Ecdysone signaling underlies the pea aphid transgenerational wing polyphenism

Vellichirammal

Gupta

Hall

et al. 2017

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

123

102

View full text Add to dashboard Cite

The wing polyphenism of pea aphids is a compelling laboratory model with which to study the molecular mechanisms underlying phenotypic plasticity. In this polyphenism, environmental stressors such as high aphid density cause asexual, viviparous adult female aphids to alter the developmental fate of their embryos from wingless to winged morphs. This polyphenism is transgenerational, in that the pea aphid mother experiences the environmental signals, but it is her offspring that are affected. Previous research suggested that the steroid hormone ecdysone may play a role in this polyphenism. Here, we analyzed ecdysone-related gene expression patterns and found that they were consistent with a down-regulation of the ecdysone pathway being involved in the production of winged offspring. We therefore predicted that reduced ecdysone signaling would result in more winged offspring. Experimental injections of ecdysone or its analog resulted in a decreased production of winged offspring. Conversely, interfering with ecdysone signaling using an ecdysone receptor antagonist or knocking down the ecdysone receptor gene with RNAi resulted in an increased production of winged offspring. Our results are therefore consistent with the idea that ecdysone plays a causative role in the regulation of the proportion of winged offspring produced in response to crowding in this polyphenism. Our results also show that an environmentally regulated maternal hormone can mediate phenotype production in the next generation, as well as provide significant insight into the molecular mechanisms underlying the functioning of transgenerational phenotypic plasticity.

show abstract

Section: Resultsmentioning

confidence: 99%

Ecdysone signaling underlies the pea aphid transgenerational wing polyphenism

Vellichirammal

Gupta

Hall

et al. 2017

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

123

102

View full text Add to dashboard Cite

show abstract

“…In terrestrial environments, there are many reports of substances produced by plants that interfere with the reproductive capacity of grazing animals and which act as a form of population control. For example, ingestion of certain phytoecdysones inhibits larval growth and development in several species of insects, as well as interferes with the breeding of domestic sheep and some wild bird populations (Robbins et al, 1968). Such anti-herbivore agents may be common in both aquatic and terrestrial habitats even though most of the attention has traditionally focussed on feeding deterrents and poisoning compounds.…”

Section: Chemical Defences In Phytoplanktonmentioning

confidence: 99%

Induced defences in marine and freshwater phytoplankton: a review

2010

View full text Add to dashboard Cite

Many organisms have developed defences to avoid predation by species at higher trophic levels. The capability of primary producers to defend themselves against herbivores affects their own survival, can modulate the strength of trophic cascades and changes rates of competitive exclusion in aquatic communities. Algal species are highly flexible in their morphology, growth form, biochemical composition and production of toxic and deterrent compounds. Several of these variable traits in phytoplankton have been interpreted as defence mechanisms against grazing. Zooplankton feed with differing success on various phytoplankton species, depending primarily on size, shape, cell wall structure and the production of toxins and deterrents. Chemical cues associated with (i) mechanical damage, (ii) herbivore presence and (iii) grazing are the main factors triggering induced defences in both marine and freshwater phytoplankton, but most studies have failed to disentangle the exact mechanism(s) governing defence induction in any particular species. Induced defences in phytoplankton include changes in morphology (e.g. the formation of spines, colonies and thicker cell walls), biochemistry (such as production of toxins, repellents) and in life history characteristics (formation of cysts, reduced recruitment rate). Our categorization of inducible defences in terms of the responsible induction mechanism provides guidance for future work, as hardly any of the available studies on marine or freshwater plankton have performed all the treatments that are required to pinpoint the actual cue(s) for induction. We discuss the ecology of inducible defences in marine and freshwater phytoplankton with a special focus on the mechanisms of induction, the types of defences, their costs and benefits, and their consequences at the community level.

show abstract

“…However, evidence pointing to the defensive role of these compounds in fern-insect interactions is largely lacking. Balick et al (1978) found no correlation between tannin levels and the amount of insect damage to 26 species of tropical ferns, and the role of the phytoecdysones in preventing insect herbivory has not been substantiated with laboratory feeding tests (Robbins et al 1968;Hendrix 1977;Jones and Firn 1978). Cyanogenic glycosides are known to be toxic to many herbivores, but their distribution in ferns appears to be limited (Balick et al 1978).…”

Section: Feeding Habits Of Insects Attacking Fernsmentioning

confidence: 99%

An Evolutionary and Ecological Perspective of the Insect Fauna of Ferns

Hendrix¹

1980

The American Naturalist

View full text Add to dashboard Cite

Ecdysones and Analogs: Effects on Development and Reproduction of Insects

Cited by 122 publications

References 20 publications

Ecdysone signaling underlies the pea aphid transgenerational wing polyphenism

Ecdysone signaling underlies the pea aphid transgenerational wing polyphenism

Induced defences in marine and freshwater phytoplankton: a review

An Evolutionary and Ecological Perspective of the Insect Fauna of Ferns

Contact Info

Product

Resources

About