Enzymes for ecdysteroid biosynthesis: their biological functions in insects and beyond

Niwa, Ryusuke; Niwa, Yuko S.

doi:10.1080/09168451.2014.942250

Cited by 200 publications

(166 citation statements)

References 104 publications

(164 reference statements)

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“…Insects produce ecdysteroid hormones (Niwa and Niwa 2014). The source of ecdysteroids in larvae and pupae is the prothoracic gland, which degenerates after metamorphosis (Snodgrass 1956;Dai and Gilbert 1997).…”

Section: Introductionmentioning

confidence: 99%

Queen mandibular pheromone modulates hemolymph ecdysteroid titers in adult Apis mellifera workers

Trawinski

Fahrbach

2018

Apidologie

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-To test the hypothesis that exposure to queen mandibular pheromone (QMP) modulates ecdysteroid production in adult worker honey bees, ecdysteroids were measured in hemolymph and other tissues of individual adult worker honey bees reared with or without QMP in cages and field colonies. Ecdysteroid titers were higher in caged workers exposed to QMP continuously from the first day of adult life than in workers reared without QMP. Statistical cluster analysis suggested the possibility that a subgroup of workers (Bresponders^) is more sensitive to QMP in this regard than other workers. In 12-day-old workers, ecdysteroid titers in workers reared in queenright (QR) colonies were similar to those observed in cages with QMP, but lower than those in queenless (QL) colonies. Differences in number of ovarioles or degree of ovarian activation did not correlate with hemolymph ecdysteroids. Previous studies have demonstrated ecdysteroids in hemolymph in very young adult workers and in workers in QL colonies; the present study indicates that production of ecdysteroids occurs in older adult worker honey bees in the absence of morphological signs of ovarian activation, with cage studies revealing a modulatory role for QMP masked in the complex environment of the hive.ecdysteroids / ovary / queen mandibular pheromone / queenless / queenright

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Section: Introductionmentioning

confidence: 99%

Queen mandibular pheromone modulates hemolymph ecdysteroid titers in adult Apis mellifera workers

Trawinski

Fahrbach

2018

Apidologie

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“…Ecdysteroids, which are produced in the prothoracic gland, trigger each larval-larval and metamorphic molt, whereas JHs, which are produced in the corpora allata (CA), prevent precocious metamorphosis and allow the larva to undergo multiple rounds of molting until it reaches the appropriate size for metamorphosis (1)(2)(3)(4)(5). It is widely considered that this "status quo" action of JH is required to maintain the larval status throughout the larval stage.…”

mentioning

confidence: 99%

Knockout silkworms reveal a dispensable role for juvenile hormones in holometabolous life cycle

Daimon

Uchibori

Nakao

et al. 2015

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

114

130

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Insect juvenile hormones (JHs) prevent precocious metamorphosis and allow larvae to undergo multiple rounds of status quo molts. However, the roles of JHs during the embryonic and very early larval stages have not been fully understood. We generated and characterized knockout silkworms (Bombyx mori) with null mutations in JH biosynthesis or JH receptor genes using genome-editing tools. We found that embryonic growth and morphogenesis are largely independent of JHs in Bombyx and that, even in the absence of JHs or JH signaling, pupal characters are not formed in first-or second-instar larvae, and precocious metamorphosis is induced after the second instar at the earliest. We also show by mosaic analysis that a pupal specifier gene broad, which is dramatically up-regulated in the late stage of the last larval instar, is essential for pupal commitment in the epidermis. Importantly, the mRNA expression level of broad, which is thought to be repressed by JHs, remained at very low basal levels during the early larval instars of JH-deficient or JH signaling-deficient knockouts. Therefore, our study suggests that the long-accepted paradigm that JHs maintain the juvenile status throughout larval life should be revised because the larval status can be maintained by a JHindependent mechanism in very early larval instars. We propose that the lack of competence for metamorphosis during the early larval stages may result from the absence of an unidentified broadinducing factor, i.e., a competence factor. juvenile hormone | metamorphosis | ecdysone | TALEN | Bombyx

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“…High concentrations of hormones in the blood vessels indicate that cells build barriers in order to maintain the homeostatic state (balanced), leading to low doses of hormones that are insufficient to stimulate actions. Fujaya and Trijuno (2007), Niwa and Niwa (2014), Techa and Chung (2015), and Ahmad et al (2015) explained that the high hormone concentrations inhibit the production receptors and the ability of cell receptors to bind to hormones causing decrement in order to inhibit protein formation, resulting in growth and molting inhibition.…”

Section: Resultsmentioning

confidence: 99%

Survival and metamorphosis rate of swimming crab Portunus pelagicus larvae with the use of phytoecdysteroid in the artificial feed

Nikhlani

Sukarti

2017

Jurnal Akuakultur Indonesia

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Survival and metamorphosis rate of swimming crab ABSTRACTThe survival rate of blue swimming crabs and the larval metamorphosis processes are still low in hatcheries. The objective of this study was to evaluate the effects of different phytoecdysteroids doses on both the survival and the rate of Blue swimmer crab larvae metamorphosis. The study consisted of four different phytoecdysteroids treatments, namely: control (0 mg/100 g of feed), 1 mg/100 g of feed, 2 mg/100 g of feed, and 4 mg/100 g of feed. Each treatment was replicated three times. The survival rate of the larvae was analyzed through analysis of variance, while the rate of larval metamorphosis was descriptively analyzed. The results showed that the dose of phytoecdysteroid of 2 mg/100 g of artificial feed resulted in the highest survival and the fastest metamorphosis speed of crab larvae for zoea-2 and zoea-3, and the dose of 4 mg/100 g of artificial feed for stadia megalopa and crablet.Keywords: phytoecdysteroids, survival rate, metamorphosis, blue swimming crab ABSTRAKKelangsungan hidup rajungan dalam pembenihan masih rendah, dan proses metamorfosis larva masih lambat. Tujuan penelitian ini adalah untuk mengevaluasi pengaruh pemberian fitoekdisteroid dosis berbeda terhadap kelangsungan hidup dan kecepatan metamorfosis larva rajungan. Penelitian ini terdiri atas empat perlakuan dosis fitoekdisteroid yang berbeda, yaitu: kontrol (0 mg/100 g pakan), 1 mg/100 g pakan, 2 mg/100 g pakan, dan 4 mg/100 g pakan dengan masing-masing perlakuan dilakukan tiga kali ulangan. Kelangsungan hidup larva dianalisis menggunakan analisis sidik ragam, sedangkan kecepatan metamorfosis larva dianalisis secara deskriptif. Hasil penelitian menunjukkan bahwa dosis fitoekdisteroid sebanyak 2 mg/100 g pakan buatan menghasilkan kelangsungan hidup tertinggi dan proses metamorfosis larva rajungan tercepat untuk stadia zoea-2 dan zoea-3, serta dosis 4 mg/100 g pakan buatan untuk stadia megalopa dan crablet.

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Enzymes for ecdysteroid biosynthesis: their biological functions in insects and beyond

Cited by 200 publications

References 104 publications

Queen mandibular pheromone modulates hemolymph ecdysteroid titers in adult Apis mellifera workers

Queen mandibular pheromone modulates hemolymph ecdysteroid titers in adult Apis mellifera workers

Knockout silkworms reveal a dispensable role for juvenile hormones in holometabolous life cycle

Survival and metamorphosis rate of swimming crab Portunus pelagicus larvae with the use of phytoecdysteroid in the artificial feed

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