Insulin-related peptides and their conserved signal transduction pathway

Claeys, Ilse; Simonet, Gert; Poels, Jeroen; Loy, Tom Van; Vercammen, Linda; Loof, Arnold De; Broeck, Jozef Vanden

doi:10.1016/s0196-9781(01)00666-0

Cited by 182 publications

(125 citation statements)

References 83 publications

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“…In insects, insulin-like peptides (secreted primarily by insulin-producing cells in the brain), probably in cooperation with growth factors (secreted by the fat bodies), bind to the insulin receptor and activate an evolutionarily conserved signal transduction cascade that controls the activity of the protein translation machinery (Weinkove and Leevers, 2000;Claeys et al, 2002; Figure 4). …”

Section: The Insulin Pathway and The Evolution Of Allometrymentioning

confidence: 99%

Insulin signaling and limb-patterning: candidate pathways for the origin and evolutionary diversification of beetle ‘horns’

et al. 2006

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Beetle 'horns' are rigid outgrowths of the insect cuticle used as weapons in contests for access to mates. Relative to their body size, beetle horns can be enormous. They protrude from any of five different regions of the head or thorax; they are curved, straight, branched or bladed; and their development is often coupled with the nutrient environment (male dimorphism) or with sex (sexual dimorphism). Here, we show that this extraordinary diversity of horns can be distilled down to four trajectories of morphological change -horn location, shape, allometry and dimorphism -and we illustrate how the developmental mechanisms regulating horn growth could generate each of these types of horn evolution. Specifically, we review two developmental pathways known to regulate growth of morphological structures in Drosophila and other insects: a limb-patterning pathway that specifies the location and shape of a structure, and the insulin pathway, which modulates trait growth in response to larval nutrition. We summarize preliminary evidence indicating that these pathways are associated with the development of beetle horns, and we show how subtle changes in the relative activities of these two pathways would be sufficient to generate most of the extant diversity of horn forms. Our objective is to intuitively connect genotype with phenotype, and to advocate an informed 'candidate gene' approach to studies of the developmental basis of evolution. We end by using this insight from development to offer a solution to the longstanding mystery of the scarabs: the observation by Darwin, Lameere, Arrow and others that this one family of beetles appeared to have a 'special tendency' towards the evolution of horns.

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Section: The Insulin Pathway and The Evolution Of Allometrymentioning

confidence: 99%

Insulin signaling and limb-patterning: candidate pathways for the origin and evolutionary diversification of beetle ‘horns’

et al. 2006

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“…More particularly, our experiments were designed to examine the hypothesis that this factor could be an insulin-like peptide (ILP). In insects indeed, ILPs are among the major products synthesized by MNCs and are thus considered as true neurohormones (for review see Smit et al 1998, Claeys et al 2002, Nässel 2002. In particular, they have been detected in the MNCs of a blowfly species ) and of Drosophila (Brogiolo et al 2001).…”

Section: Introductionmentioning

confidence: 99%

“…Bombyxin, an ILP isolated from silkworm brain was found to stimulate steroidogenesis in the molting glands of lepidopteran larvae (Nagasawa et al 1986) and to have also some unknown role during reproduction, as indicated by the detection of specific receptors in ovaries (Fullbright et al 1997). Several studies have also demonstrated that ILP receptors and their transduction mechanisms are involved in the control of reproduction in several insect species, in particular the fruitfly (for review see Claeys et al 2002, Garofalo 2002. The ILP receptor gene is mainly expressed in adult ovaries, particularly in the follicle cells (Fullbright et al 1997, Graf et al 1997, Helbling & Graf 1998, Riehle & Brown 2002 which are considered as the source of ovarian ecdysteroids (Goltzené et al 1978, Chavez et al 2000.…”

Section: Introductionmentioning

confidence: 99%

Control of ovarian steroidogenesis by insulin-like peptides in the blowfly (Phormia regina)

Manière¹,

Rondot²,

Büllesbach³

et al. 2004

Journal of Endocrinology

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This study investigated the ability of insulin and of insect insulin-like peptides (ILPs) to stimulate ovarian steroidogenesis in the blowfly Phormia regina. Bovine insulin was active on ovaries isolated in vitro, which showed an age-dependent sensitivity; this peptide progressively stimulated steroidogenesis in ovaries isolated from the third day after adult molt, but not in younger ones, and had maximal activity after the fifth day. This stimulatory effect was observed equally from females reared in the presence or in the absence of males, excluding a regulatory effect of mating. The mode of action of insulin in blowflies did not involve cAMP, but triggered a specific and well-conserved transduction cascade. In particular, a peroxovanadium compound, known to activate specifically the insulin receptor in mammals, also stimulated blowfly ovarian steroidogenesis in vitro. Conversely, chemicals known to inhibit the mammalian insulin receptor or downstream elements of its signaling pathway, such as LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3K), were able to prevent the steroidogenic action of bovine insulin on fly ovaries. Extracts from the median neurosecretory cells (MNCs) of blowfly brains, which are known to contain endogenous ILPs, stimulated ovarian steroidogenesis very efficiently and were also sensitive to inhibition by LY294002. These experiments indicated the involvement of PI3K in the mode of action of MNC extracts and substantiated that their endogenous ILPs are involved in the regulation of ovarian steroidogenesis. This conclusion was corroborated by the effects of synthetic bombyxin II, an ILP originating from silkworm MNCs, which also stimulated steroidogenesis in isolated blowfly ovaries. Altogether, these data suggest that insulinlike neurohormones from MNCs play a crucial role as steroidogenic gonadotropins in female flies.

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“…1). [19][20][21][22][23][24] Nevertheless, not all traits show the same variability in response to variation in developmental nutrition. Some organs, for example the human brain, are able to protect themselves from the effects of malnutrition and grow to more or less the same size in both well fed and poorly fed individuals.…”

Section: The Developmental Regulation Of Nutritional Variabilitymentioning

confidence: 99%