scholarly journals Higher, Faster, Better: Maternal Effects Shorten Time Lags and Increase Morphological Defenses in Daphnia lumholtzi Offspring Generations

2021 ◽  
Vol 9 ◽  
Author(s):  
Annette Graeve ◽  
Marjan Janßen ◽  
Mariana Villalba de la Pena ◽  
Ralph Tollrian ◽  
Linda C. Weiss
Keyword(s):  
Phenotypic Plasticity ◽  
Gasterosteus Aculeatus ◽  
Cost Benefit ◽  
Lag Phase ◽  
Inducible Defenses ◽  
Time Lags ◽  
Daphnia Lumholtzi ◽  
Freshwater Crustacean ◽  
Offspring Generation ◽  
Lag Phases

Prey species can respond to the presence of predators by inducing phenotypic plastic traits which form morphological, life history or behavioral defenses. These so-called inducible defenses have evolved within a cost-benefit framework. They are only formed when they are needed, and costs associated with defenses are saved when predators are not present. However, a disadvantage compared to permanent defenses are lag phases between predator perception and the full formation of defenses. This may be especially important when the predation risk persists for longer periods, e.g., outlasts one generation and challenges prey offspring. We hypothesized that transgenerational induced phenotypic plasticity reduces lag phases in situations where hazards threaten specimens over several generations. We tested this in three generations of the freshwater crustacean Daphnia lumholtzi using the three-spined stickleback Gasterosteus aculeatus as predator. In the presence of chemical cues from fish D. lumholtzi expresses elongated head and tail spines. In the F0 generation defenses are constraint by a comparatively long lag phase and are not developed prior to the 3rd instar. In the F1, and F2 of induced animals this lag phase is shortened and defenses are developed upon birth. We show that induction of TGP in the mothers takes place already during the juvenile stages and transfers to the offspring generation in forms of shortened time lags and enhanced trait expression. When progeny is additionally exposed to fish cues as embryos, the addition of maternal and embryonic effects further enhances the magnitude of defense expression. Our findings detail a distinguished strategy of transgenerational phenotypic plasticity which allows to shorten lag phases of trait changes in phenotypic plasticity.

Gastric emptying as assessed by barium-impregnated polyethylene spheres in healthy dogs consuming a commercial kibble ration

2001 ◽  
Vol 37 (5) ◽  
pp. 444-452 ◽  
Author(s):  
OL Nelson ◽  
AE Jergens ◽  
KG Miles ◽  
WF Christensen
Keyword(s):  
Gastric Emptying ◽  
Test Meal ◽  
Lag Phase ◽  
Significant Difference ◽  
Before And After ◽  
Healthy Dogs ◽  
Lag Phases

Barium-impregnated polyethylene spheres (BIPS) were used to assess gastric emptying in medium-sized dogs consuming a commercial kibble ration. Two sizes of spheres were used: 1.5 mm and 5.0 mm in diameter. Ventrodorsal and right lateral recumbent radiographs were taken immediately before and after consumption of the test meal, and then hourly. The lag phase and the time to 25% (GET25), 50% (GET50), and 75% (GET75) gastric emptying of each sized marker were calculated. There was no significant difference between the lag phases of the small and large BIPS. There was a significant difference between the 1.5 and 5.0 markers at GET25, GET50, and GET75 in these medium-sized dogs. In a majority (70%) of the dogs in this study, GET25 of the 1.5-mm marker occurred at 4.73+/-1.44 hours; GET50 (1.5 mm) occurred at 8.29+/-1.62 hours, and GET75 (1.5 mm) occurred at 10.82+/-1.35 hours. The 5.0-mm markers tended to empty erratically and slowly. Four of the eight dogs retained some of the large markers in their stomachs at the end of the study period (24 hours).

Predator-induced phenotypic plasticity in the exotic cladoceran Daphnia lumholtzi

2003 ◽  
Vol 48 (9) ◽  
pp. 1593-1602 ◽  
Author(s):  
Andrew R. Dzialowski ◽  
Jay T. Lennon ◽  
W.J. O'Brien ◽  
Val H. Smith
Keyword(s):  
Phenotypic Plasticity ◽  
Daphnia Lumholtzi

scholarly journals Brain volume increase and neuronal plasticity underly predator-induced morphological defense expression in Daphnia longicephala

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A Graeve ◽  
I Ioannidou ◽  
J Reinhard ◽  
D. M. Görl ◽  
A Faissner ◽  
...  
Keyword(s):  
Nervous System ◽  
Cost Benefit ◽  
Structural Plasticity ◽  
Central Component ◽  
Volume Increase ◽  
Environmental Signals ◽  
Predator Cues ◽  
Functional Changes ◽  
Morphological Defense ◽  
Freshwater Crustacean

AbstractPredator-induced phenotypic plasticity describes the ability of prey to respond to an increased predation risk by developing adaptive phenotypes. Upon the perception of chemical predator cues, the freshwater crustacean Daphnia longicephala develops defensive crests against its predator Notonecta spec. (Heteroptera). Chemical predator perception initiates a cascade of biological reactions that leads to the development of these morphological features. Neuronal signaling is a central component in this series, however how the nervous system perceives and integrates environmental signals is not well understood. As neuronal activity is often accompanied by functional and structural plasticity of the nervous system, we hypothesized that predator perception is associated with structural and functional changes of nervous tissues. We observe structural plasticity as a volume increase of the central brain, which is independent of the total number of brain cells. In addition, we find functional plasticity in form of an increased number of inhibitory post-synaptic sites during the initial stage of defense development. Our results indicate a structural rewiring of nerve-cell connections upon predator perception and provide important insights into how the nervous system of prey species interprets predator cues and develops cost–benefit optimized defenses.

scholarly journals Survival of Unstressed and Acid-, Cold-, and Starvation-Stress-AdaptedListeria monocytogenesin Ham Extract with Hops Beta Acids and Consumer Acceptability of HBA on Ready-to-Eat Ham

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Li Wang ◽  
Cangliang Shen
Keyword(s):  
Growth Rate ◽  
Listeria Monocytogenes ◽  
Sensory Evaluation ◽  
Growth Rates ◽  
Rapid Growth ◽  
Consumer Acceptability ◽  
Lag Phase ◽  
Starvation Stress ◽  
Hedonic Scale ◽  
Lag Phases

The efficacy of hops beta acids (HBA) against unstressed and stress-adaptedListeria monocytogenesin ham extract and the consumers’ acceptability of HBA on ready-to-eat (RTE) hams were investigated. Unstressed or acid-, cold-, or starvation-stress-adaptedL. monocytogeneswas inoculated (1.3–1.5 log CFU/mL) into 10% ham extract, without (control) or with HBA (4.44 or 10.0 µg/mL). Survival/growth of the pathogen during storage (7.2°C, 26 days) was monitored periodically. Sensory evaluation (30 participants, 9-point hedonic scale) was performed with hams dipped into 0.05, 0.11, and 0.23% HBA solution. Ham extracts without HBA supported rapid growth of unstressed and stress-adapted cells with growth rates of 0.39–0.71 log CFU/mL/day and lag phases of 0–3.26 days. HBA inhibited growth of unstressedL. monocytogenesby slowing (P<0.05) growth rate (0.24–0.29 log CFU/mL/day) and increasing (P<0.05) length of the lag phase (3.49–12.98 days) compared to control. Acid-, cold-, or starvation-stress-adapted cells showed cross protection against HBA with greater (P<0.05) growth rates (0.44–0.66 log CFU/mL/day) and similar or shorter lag phases (0–5.44 days) than unstressed cells. HBA did not (P>0.05) affect sensory attributes of RTE ham. These results are useful for RTE meat processors to develop operational protocols using HBA to controlL. monocytogenes.

scholarly journals Gene expression stasis and plasticity following migration into a foreign environment

2017 ◽  
Author(s):  
Brian K. Lohman ◽  
William E. Stutz ◽  
Daniel I. Bolnick
Keyword(s):  
Gene Expression ◽  
Phenotypic Plasticity ◽  
Expression Profile ◽  
Gasterosteus Aculeatus ◽  
Expression Profiles ◽  
Survival Rates ◽  
Gene Expression Profiles ◽  
Genes Expression ◽  
The Impact ◽  
Fish Performance

AbstractSelection against migrants is key to maintaining genetic differences between populations linked by dispersal. Yet, migrants are not just passively weeded out by selection. Migrants may mitigate fitness costs by proactively choosing among available habitats, or by phenotypic plasticity. We previously reported that a reciprocal transplant of lake and stream stickleback (Gasterosteus aculeatus) found little support for divergent selection. We revisit that experiment to test whether phenotypic plasticity in gene expression may have helped migrants adjust to unfamiliar habitats. We measured gene expression profiles in stickleback via TagSeq and tested whether migrants between lake and stream habitats exhibited a plastic response to their new environment that allowed them to converge on the expression profile of adapted natives. We report extensive gene expression differences between genetically divergent lake and stream stickleback, despite gene flow. But for many genes, expression was highly plastic. Fish transplanted into the adjoining habitat partially converged on the expression profile typical of their new habitat. This suggests that expression plasticity may soften the impact of migration. Nonetheless, lake and stream fish differed in survival rates and parasite infection rates in our study, implying that expression plasticity is not fast or extensive enough to fully homogenize fish performance.

scholarly journals The Crabtree Effect Shapes theSaccharomyces cerevisiaeLag Phase during the Switch between Different Carbon Sources

mBio ◽  
2018 ◽  
Vol 9 (5) ◽  
Author(s):  
Gemma Perez-Samper ◽  
Bram Cerulus ◽  
Abbas Jariani ◽  
Lieselotte Vermeersch ◽  
Nuria Barrajón Simancas ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Carbon Sources ◽  
Anaerobic Growth ◽  
Lag Phase ◽  
Crabtree Effect ◽  
Molecular Processes ◽  
Content Type ◽  
A Genome ◽  
Growth Experiments ◽  
Lag Phases

ABSTRACTWhen faced with environmental changes, microbes often enter a temporary growth arrest during which they reprogram the expression of specific genes to adapt to the new conditions. A prime example of such a lag phase occurs when microbes need to switch from glucose to other, less-preferred carbon sources. Despite its industrial relevance, the genetic network that determines the duration of the lag phase has not been studied in much detail. Here, we performed a genome-wide Bar-Seq screen to identify genetic determinants of theSaccharomyces cerevisiaeglucose-to-galactose lag phase. The results show that genes involved in respiration, and specifically those encoding complexes III and IV of the electron transport chain, are needed for efficient growth resumption after the lag phase. Anaerobic growth experiments confirmed the importance of respiratory energy conversion in determining the lag phase duration. Moreover, overexpression of the central regulator of respiration,HAP4, leads to significantly shorter lag phases. Together, these results suggest that the glucose-induced repression of respiration, known as the Crabtree effect, is a major determinant of microbial fitness in fluctuating carbon environments.IMPORTANCEThe lag phase is arguably one of the prime characteristics of microbial growth. Longer lag phases result in lower competitive fitness in variable environments, and the duration of the lag phase is also important in many industrial processes where long lag phases lead to sluggish, less efficient fermentations. Despite the immense importance of the lag phase, surprisingly little is known about the exact molecular processes that determine its duration. Our study uses the molecular toolbox ofS. cerevisiaecombined with detailed growth experiments to reveal how the transition from fermentative to respirative metabolism is a key bottleneck for cells to overcome the lag phase. Together, our findings not only yield insight into the key molecular processes and genes that influence lag duration but also open routes to increase the efficiency of industrial fermentations and offer an experimental framework to study other types of lag behavior.

scholarly journals Thwarting predators? A three-dimensional perspective of morphological alterations in the freshwater crustacean Daphnia

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254263
Author(s):  
Martin Horstmann ◽  
Ralph Tollrian ◽  
Linda C. Weiss
Keyword(s):  
Morphological Changes ◽  
Three Dimensional ◽  
Foraging Strategies ◽  
Inducible Defenses ◽  
Predator Prey ◽  
Morphological Alterations ◽  
Morphological Adaptations ◽  
Freshwater Crustacean ◽  
Tadpole Shrimp ◽  
Interspecific Comparisons

Predation is a major selective agent, so that many taxa evolved phenotypically plastic defensive mechanisms. Among them are many species of the microcrustacean genus Daphnia, which respond to an increased predation risk by developing inducible morphological alterations. Some of these features are obvious and easily recognized, e.g., crests in D. longicephala, while others are rather hidden, such as the bulkier shape of D. magna induced by the presence of the tadpole shrimp Triops. In this study we investigated the extraordinary diversity of morphological adaptations in the presence of predators with different foraging strategies in six predator-prey systems. For the first time we were able to analyze the unexposed and predator-exposed morphs comprehensively using three-dimensional scanning and reconstruction. We show that morphological changes are manifold in appearance between species and predators, and go beyond what has been known from previous 2D analyses. This further demonstrates the enormous trait flexibility of Daphnia. Interestingly, we found that among this variety some species share morphological strategies to counter a predator, while others use a different strategy against the same predator. Based on these intra- and interspecific comparisons, we discuss the mechanisms by which the respective defense might operate. These data therefore contribute to a deeper understanding of the inducible defenses’ morphology as well as their diversified modes of operation in Daphnia, being a cornerstone for subsequent investigations, including the determination of costs associated with morphological change.

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