| evolution of a predator-induced, nonlinear reaction norm. | inducible, anti-predator traits are a classic example of phenotypic plasticity. their evolutionary dynamics depend on their genetic basis, the historical pattern of predation risk that populations have experienced and current selection gradients. when populations experience predators with contrasting hunting strategies and size preferences, theory suggests contrasting micro-evolutionary responses to selection. daphnia pulex is an ideal species to explore the micro-evolutionary response of anti-p ... | 2017 | 28835554 |
| phenotypic plasticity in three daphnia genotypes in response to predator kairomone: evidence for an involvement of chitin deacetylases. | the genetic background of inducible morphological defences in daphnia is still largely unknown. dissolved infochemicals from the aquatic larvae of the phantom midge chaoborus induce so-called 'neck-teeth' in the first three post-embryonic stages of daphnia pulex this defence has become a textbook example of inducible defences. in a target gene approach, by using three daphnia genotypes which show a gradient of neck-teeth induction in response to equal amounts of kairomone, we report a high corre ... | 2016 | 26994174 |
| ionotropic glutamate receptors mediate inducible defense in the water flea daphnia pulex. | phenotypic plasticity is the ability held in many organisms to produce different phenotypes with a given genome in response to environmental stimuli, such as temperature, nutrition and various biological interactions. it seems likely that environmental signals induce a variety of mechanistic responses that influence ontogenetic processes. inducible defenses, in which prey animals alter their morphology, behavior and/or other traits to help protect against direct or latent predation threats, are ... | 2015 | 25799112 |
| identification of the precise kairomone-sensitive period and histological characterization of necktooth formation in predator-induced polyphenism in daphnia pulex. | many organisms have the ability to alter their development in the presence of predators, leading to predator-induced defenses that reduce vulnerability to predation. in the water flea daphnia pulex, small protuberances called 'neckteeth' form in the dorsal neck region in response to kairomone(s) released by predatory phantom midges (chaoborus larvae). although previous studies suggested that kairomone sensitivity begins when chemoreceptors begin to function during embryogenesis, the exact critic ... | 2013 | 23915154 |
| predator-induced defences in daphnia pulex: selection and evaluation of internal reference genes for gene expression studies with real-time pcr. | the planktonic microcrustacean daphnia pulex is among the best-studied animals in ecological, toxicological and evolutionary research. one aspect that has sustained interest in the study system is the ability of d. pulex to develop inducible defence structures when exposed to predators, such as the phantom midge larvae chaoborus. the available draft genome sequence for d. pulex is accelerating research to identify genes that confer plastic phenotypes that are regularly cued by environmental stim ... | 2010 | 20587017 |
| the reaction norm of size and age at maturity under multiple predator risk. | 1. two major theories underpin our understanding of how predation risk shapes life history. the first is centred around predator induced changes in activity that subsequently reduce food intake and thus growth. the second is centred around size selective, predator induced changes in development. 2. here, we challenge these theories using experiments and probabilistic models of maturation reaction norms to investigate predator induced life history in the water flea daphnia pulex facing two differ ... | 2010 | 20522144 |
| conservation of the notch antagonist hairless in arthropods: functional analysis of the crustacean daphnia pulex hairless gene. | the notch signaling pathway is highly conserved in all animal metazoa: upon notch receptor activation, transcription of notch target genes is turned on by an activator complex that centers on the transcription factor csl. in the absence of signal, csl assembles transcriptional repression complexes that display remarkable evolutionary diversity. the major antagonist of notch signaling in insects named hairless was originally identified in drosophila melanogaster. it binds to the drosophila csl ho ... | 2017 | 28861687 |
| biological activity of the predicted red pigment-concentrating hormone of daphnia pulex in a crustacean and an insect. | the elucidation of the genome of the waterflea daphnia pulex made it possible to search for orthologue genes for the crustacean red pigment-concentrating hormone (named panbo-rpch after the species pandalus borealis in which the red pigment-concentrating hormone was first identified); panbo-rpch is a member of the adipokinetic hormone (akh)/red pigment-concentrating hormone (rpch) peptide family. the information pointed to a putative mature rpch octapeptide in d. pulex with the primary sequence ... | 2010 | 19686751 |
| pulsed light reduces the toxicity of the algal toxin okadaic acid to freshwater crustacean daphnia pulex. | this constitutes the first study to report on the reduction in toxicity of the dinoflagellate algal toxin okadaic acid after novel pulsed light (pl) treatments where ecotoxicological assessment was performed using a miniaturised format of the conventional in vivo freshwater crustacean daphnia sp. acute toxicity test. bivalves accumulate this toxin, which can then enter the human food chain causing deleterious health effects such as diarrhetic shellfish poisoning. this miniaturised toxicological ... | 2018 | 29052147 |
| dynamic evolution and biogenesis of small rnas during sex reversal. | understanding origin, evolution and functions of small rna (srna) genes has been a great challenge in the past decade. molecular mechanisms underlying sexual reversal in vertebrates, particularly srnas involved in this process, are largely unknown. by deep-sequencing of small rna transcriptomes in combination with genomic analysis, we identified a large amount of pirnas and mirnas including over 1,000 novel mirnas, which were differentially expressed during gonad reversal from ovary to testis vi ... | 2015 | 25944477 |
| function, diversity, and application of insect juvenile hormone epoxidases (cyp15). | juvenile hormones (jhs) represent a family of sesquiterpenoid hormones in insects, and they play a key role in regulating development, metamorphosis, and reproduction. the last two steps of the jh biosynthetic pathway, epoxidation and methyl esterification of farnesoic acid to jh, are insect specific, and thus have long been considered a promising target for biorational insecticides. recently, the enzymes involved in the last two steps have been molecularly identified: jh acid methyltransferase ... | 2017 | 23586995 |