Developmental plasticity

About: Developmental plasticity is a research topic. Over the lifetime, 1721 publications have been published within this topic receiving 103438 citations.

Cardiorespiratory physiological phenotypic plasticity in developing air-breathing anabantid fishes (Betta splendens and Trichopodus trichopterus)

Abstract: Developmental plasticity of cardiorespiratory physiology in response to chronic hypoxia is poorly understood in larval fishes, especially larval air-breathing fishes, which eventually in their development can at least partially “escape” hypoxia through air breathing. Whether the development air breathing makes these larval fishes less or more developmentally plastic than strictly water breathing larval fishes remains unknown. Consequently, developmental plasticity of cardiorespiratory physiology was determined in two air-breathing anabantid fishes (Betta splendens and Trichopodus trichopterus). Larvae of both species experienced an hypoxic exposure that mimicked their natural environmental conditions, namely chronic nocturnal hypoxia (12 h at 17 kPa or 14 kPa), with a daily return to diurnal normoxia. Chronic hypoxic exposures were made from hatching through 35 days postfertilization, and opercular and heart rates measured as development progressed. Opercular and heart rates in normoxia were not affected by chronic nocturnal hypoxic. However, routine oxygen consumption M˙O2 (~4 μmol·O2/g per hour in normoxia in larval Betta) was significantly elevated by chronic nocturnal hypoxia at 17 kPa but not by more severe (14 kPa) nocturnal hypoxia. Routine M˙O2 in Trichopodus (6–7 μmol·O2/g per hour), significantly higher than in Betta, was unaffected by either level of chronic hypoxia. PCrit, the PO2 at which M˙O2 decreases as ambient PO2 falls, was measured at 35 dpf, and decreased with increasing chronic hypoxia in Betta, indicating a large, relatively plastic hypoxic tolerance. However, in contrast, PCrit in Trichopodus increased as rearing conditions grew more hypoxic, suggesting that hypoxic acclimation led to lowered hypoxic resistance. Species-specific differences in larval physiological developmental plasticity thus emerge between the relatively closely related Betta and Trichopodus. Hypoxic rearing increased hypoxic tolerance in Betta, which inhabits temporary ponds with nocturnal hypoxia. Trichopodus, inhabiting more permanent oxygenated bodies of water, showed few responses to hypoxia, reflecting a lower degree of developmental phenotypic plasticity.

Expression profiling of winged- and wingless-destined pea aphid embryos implicates insulin/insulin growth factor signaling in morph differences.

Abstract: Developmental plasticity allows the matching of adult phenotypes to different environments. Although considerable effort has gone into understanding the evolution and ecology of plasticity, less is known about its developmental genetic basis. We focused on the pea aphid wing polyphenism, in which high- or low-density environments cause viviparous aphid mothers to produce winged or wingless offspring, respectively. Maternally provided ecdysone signals to embryos to be winged or wingless, but it is unknown how embryos respond to that signal. We used transcriptional profiling to investigate the gene expression state of winged-destined (WD) and wingless-destined (WLD) embryos at two developmental stages. We found that embryos differed in a small number of genes, and that gene sets were enriched for the insulin-signaling portion of the FoxO pathway. To look for a global signature of insulin signaling, we examined the size and stage of WD and WLD embryos but found no differences. These data suggest the hypothesis that FoxO signaling is important for morph development in a tissue-specific manner. We posit that maternally supplied ecdysone affects embryonic FoxO signaling, which ultimately plays a role in alternative morph development. Our study is one of an increasing number that implicate insulin signaling in the generation of alternative environmentally induced morphologies.

Translation regulation in sleep: Making experience last.

Abstract: Sleep improves cognition and is necessary for normal brain plasticity, but the precise cellular and molecular mechanisms mediating these effects are unknown At the molecular level, experience-dependent synaptic plasticity triggers new gene and protein expression necessary for long-lasting changes in synaptic strength1 In particular, translation of mRNAs at remodeling synapses is emerging as an important mechanism in persistent forms of synaptic plasticity in vitro and certain forms of memory consolidation2 We have previously shown that sleep is required for the consolidation of a canonical model of in vivo plasticity (ie, ocular dominance plasticity [ODP] in the developing cat)3 Using this model, we recently showed that protein synthesis during sleep participates in the consolidation process We demonstrate that activation of the mammalian target of rapamycin [mTOR] pathway, an important regulator of translation initiation,4 is necessary for sleep-dependent ODP consolidation and that sleep promotes translation (but not transcription) of proteins essential for synaptic plasticity (ie, ARC and BDNF) Our study thus reveals a previously unknown mechanism operating during sleep that consolidates cortical plasticity in vivo

Natural selection mediated by seasonal time constraints increases the alignment between evolvability and developmental plasticity.

Abstract: Phenotypic plasticity can either hinder or promote adaptation to novel environments. Recent studies that have quantified alignments between plasticity, genetic variation, and divergence propose that such alignments may reflect constraints that bias future evolutionary trajectories. Here, we emphasize that such alignments may themselves be a result of natural selection and do not necessarily indicate constraints on adaptation. We estimated developmental plasticity and broad sense genetic covariance matrices (G) among damselfly populations situated along a latitudinal gradient in Europe. Damselflies were reared at photoperiod treatments that simulated the seasonal time constraints experienced at northern (strong constraints) and southern (relaxed constraints) latitudes. This allowed us to partition the effects of (1) latitude, (2) photoperiod, and (3) environmental novelty on G and its putative alignment with adaptive plasticity and divergence. Environmental novelty and latitude did not affect G, but photoperiod did. Photoperiod increased evolvability in the direction of observed adaptive divergence and developmental plasticity when G was assessed under strong seasonal time constraints at northern (relative to southern) photoperiod. Because selection and adaptation under time constraints is well understood in Lestes damselflies, our results suggest that natural selection can shape the alignment between divergence, plasticity, and evolvability.