scholarly journals Cold shock induces a terminal investment reproductive response in C. elegans

2021 ◽  
Author(s):  
Leah Gulyas ◽  
Jennifer R. Powell
Keyword(s):  
Life History Traits ◽  
Cold Shock ◽  
Reproductive Investment ◽  
Environmental Stressors ◽  
Offspring Survival ◽  
Future Studies ◽  
Terminal Investment ◽  
C Elegans ◽  
Reproductive Response ◽  
Maternal Provisioning

AbstractChallenges from environmental stressors have a profound impact on many life-history traits of an organism, including reproductive strategy. Examples across multiple taxa have demonstrated that maternal reproductive investment resulting from stress can improve offspring survival; a form of matricidal provisioning when death appears imminent is known as terminal investment. Here we report a reproductive response in the nematode Caenorhabditis elegans upon exposure to acute cold shock at 2°C, whereby vitellogenic lipid movement from the soma to the germline appears to be massively upregulated at the expense of parental survival. This response is dependent on functional TAX-2;TAX-4 cGMP-gated channels that are part of canonical thermosensory mechanisms in worms and can be prevented in the presence of activated SKN-1/Nrf2, the master stress regulator. Increased maternal provisioning promotes improved embryonic cold shock survival, which is notably suppressed in animals with impaired vitellogenesis. These findings suggest that cold shock in C. elegans triggers terminal investment to promote progeny fitness at the expense of parental survival and may serve as a tractable model for future studies of stress-induced progeny plasticity.

scholarly journals Natural variation in fecundity is correlated with species-wide levels of divergence in Caenorhabditis elegans

2021 ◽  
Author(s):  
Gaotian Zhang ◽  
Jake D Mostad ◽  
Erik C Andersen
Keyword(s):  
Life History ◽  
Caenorhabditis Elegans ◽  
Life History Traits ◽  
Life History Trait ◽  
Selective Sweeps ◽  
C Elegans ◽  
Genome Wide ◽  
Genetic Complexity ◽  
Genomic Regions ◽  
Global Population

Abstract Life history traits underlie the fitness of organisms and are under strong natural selection. A new mutation that positively impacts a life history trait will likely increase in frequency and become fixed in a population (e.g. a selective sweep). The identification of the beneficial alleles that underlie selective sweeps provides insights into the mechanisms that occurred during the evolution of a species. In the global population of Caenorhabditis elegans, we previously identified selective sweeps that have drastically reduced chromosomal-scale genetic diversity in the species. Here, we measured the fecundity of 121 wild C. elegans strains, including many recently isolated divergent strains from the Hawaiian islands and found that strains with larger swept genomic regions have significantly higher fecundity than strains without evidence of the recent selective sweeps. We used genome-wide association (GWA) mapping to identify three quantitative trait loci (QTL) underlying the fecundity variation. Additionally, we mapped previous fecundity data from wild C. elegans strains and C. elegans recombinant inbred advanced intercross lines that were grown in various conditions and detected eight QTL using GWA and linkage mappings. These QTL show the genetic complexity of fecundity across this species. Moreover, the haplotype structure in each GWA QTL region revealed correlations with recent selective sweeps in the C. elegans population. North American and European strains had significantly higher fecundity than most strains from Hawaii, a hypothesized origin of the C. elegans species, suggesting that beneficial alleles that caused increased fecundity could underlie the selective sweeps during the worldwide expansion of C. elegans.

scholarly journals Deep learning-enabled analysis reveals distinct neuronal phenotypes induced by aging and cold-shock

BMC Biology ◽  
2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Sahand Saberi-Bosari ◽  
Kevin B. Flores ◽  
Adriana San-Miguel
Keyword(s):  
Deep Learning ◽  
Cold Shock ◽  
Morphological Changes ◽  
Quantitative Information ◽  
Qualitative Assessment ◽  
Morphological Alteration ◽  
Phenotypic Profile ◽  
C Elegans ◽  
Unbiased Manner ◽  
Neural Network Algorithm

Abstract Background Access to quantitative information is crucial to obtain a deeper understanding of biological systems. In addition to being low-throughput, traditional image-based analysis is mostly limited to error-prone qualitative or semi-quantitative assessment of phenotypes, particularly for complex subcellular morphologies. The PVD neuron in Caenorhabditis elegans, which is responsible for harsh touch and thermosensation, undergoes structural degeneration as nematodes age characterized by the appearance of dendritic protrusions. Analysis of these neurodegenerative patterns is labor-intensive and limited to qualitative assessment. Results In this work, we apply deep learning to perform quantitative image-based analysis of complex neurodegeneration patterns exhibited by the PVD neuron in C. elegans. We apply a convolutional neural network algorithm (Mask R-CNN) to identify neurodegenerative subcellular protrusions that appear after cold-shock or as a result of aging. A multiparametric phenotypic profile captures the unique morphological changes induced by each perturbation. We identify that acute cold-shock-induced neurodegeneration is reversible and depends on rearing temperature and, importantly, that aging and cold-shock induce distinct neuronal beading patterns. Conclusion The results of this work indicate that implementing deep learning for challenging image segmentation of PVD neurodegeneration enables quantitatively tracking subtle morphological changes in an unbiased manner. This analysis revealed that distinct patterns of morphological alteration are induced by aging and cold-shock, suggesting different mechanisms at play. This approach can be used to identify the molecular components involved in orchestrating neurodegeneration and to characterize the effect of other stressors on PVD degeneration.

scholarly journals Interspecies Systems Biology Uncovers Metabolites Affecting C. elegans Gene Expression and Life History Traits

Cell ◽  
2014 ◽  
Vol 156 (4) ◽  
pp. 759-770 ◽  
Author(s):  
Emma Watson ◽  
Lesley T. MacNeil ◽  
Ashlyn D. Ritter ◽  
L. Safak Yilmaz ◽  
Adam P. Rosebrock ◽  
...  
Keyword(s):  
Gene Expression ◽  
Life History ◽  
Systems Biology ◽  
Life History Traits ◽  
C Elegans

Effects of soybean resistance on variability in life history traits of the higher trophic level parasitoidMeteorus pulchricornis(Hymenoptera: Braconidae)

2016 ◽  
Vol 107 (1) ◽  
pp. 1-8 ◽  
Author(s):  
X. Li ◽  
B. Li ◽  
G. Xing ◽  
L. Meng
Keyword(s):  
Life History ◽  
Trophic Level ◽  
Life History Traits ◽  
Offspring Survival ◽  
Lifetime Fecundity ◽  
Soybean Cultivars ◽  
Adult Body ◽  
Meteorus Pulchricornis ◽  
Soybean Resistance ◽  
Resistant Genotypes

AbstractTo extrapolate the influence of plant cultivars varying in resistance levels to hosts on parasitoid life history traits, we estimated variation in parasitoid developmental and reproductive performances as a function of resistance in soybean cultivars, which were randomly chosen from a line of resistant genotypes. Our study showed that the parasitoidMeteorus pulchricornisvaried widely in offspring survival and lifetime fecundity, but varied slightly in development time and adult body size, in response to the soybean cultivars that varied in resistance to the hostSpodoptera litura. Furthermore, the variability in survival and lifetime fecundity was different between attacking the 2nd and the 4th instar host larvae, varying more in survival but less in lifetime fecundity when attacking the 4th than 2nd instar larvae. Our study provides further evidence supporting that plant resistance to herbivorous hosts have variable effects on different life history traits of higher trophic level parasitoids.

scholarly journals Experience Modulates the Reproductive Response to Heat Stress in C. elegans via Multiple Physiological Processes

PLoS ONE ◽  
2015 ◽  
Vol 10 (12) ◽  
pp. e0145925 ◽  
Author(s):  
Devin Y. Gouvêa ◽  
Erin Z. Aprison ◽  
Ilya Ruvinsky
Keyword(s):  
Heat Stress ◽  
C Elegans ◽  
Physiological Processes ◽  
Reproductive Response

scholarly journals Multiple mechanisms in which agricultural insects respond to environmental stressors: canalization, plasticity and evolution

2020 ◽  
Vol 37 (1) ◽  
pp. 90-99
Author(s):  
Yeisson Gutiérrez
Keyword(s):  
Multiple Stressors ◽  
Short Review ◽  
Environmental Stressors ◽  
Negative Consequences ◽  
Ecological Functions ◽  
Policy Makers ◽  
Future Studies ◽  
Manipulative Experiments ◽  
Insect Biology ◽  
Insect Decline

Insects are a paramount component of biodiversity in terms of taxonomic richness, ecological functions and ecosystem services. However, many human activities have negative consequences on such organisms, causing changes in their morphology, physiology, behaviour, and even causing mass deaths leading to the well-recognized insect decline phenomenon. Although the effects of some environmental stressors (e.g. global warming and pesticides) on insect biology are fairly well understood, there is a plethora of stressors that that have only recently been considered. Additionally, although the exposure to multiple stressors is a common scenario in natural conditions, our knowledge on insect responses in this regard is still incipient. Knowledge that is in much need to inform policy makers in the fight against global change. Here, a short review on prominent environmental stressors, and the known responses that insects may exhibit, which are summarized as canalization, plasticity and evolution is provided. Furthermore, an outlook and recommendation for future studies aiming to elucidate the effects of environmental stressors (both lone and mixed) on insect biology is given. This manuscript advocates for controlled (lab or semi-field) manipulative experiments that implement realistic environmental conditions and that ideally combine several stressors.

scholarly journals Life-history traits and intra-cohort divergence of clearhead icefish (Protosalanx chinensis), indicating cannibalism increased fitness

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9900
Author(s):  
Fujiang Tang ◽  
Wei Liu ◽  
Jilong Wang ◽  
James Henne
Keyword(s):  
Life History Traits ◽  
Direct Evidence ◽  
Reproductive Investment ◽  
Bimodal Distribution ◽  
Stomach Content Analysis ◽  
Population Demographics ◽  
Spawning Period ◽  
Survival And Reproduction ◽  
One Year ◽  
Modal Group

Cannibalism is considered one of the causes of intra-cohort size divergence in fish and is usually believed to result in increased fitness in terms of survival and reproduction, but direct evidence of this is lacking. Population demographics of the clearhead icefish (Protosalanx chinensis) from Lake Xingkai (Khanka) were investigated for one year. Size-frequencies exhibited a bimodal distribution from July through January, where the population diverged into an upper and a lower modal group based on size. Stomach content analysis confirmed the occurrence of cannibalism, where fish belonging to the larger, upper modal group preyed upon those of the smaller, lower modal group. We found P. chinensis does not spawn until all of the oocytes have reached maturity and then a single spawning event occurs although the oocytes may develope asynchronously in the ovary. Upper modal group females matured slightly earlier than those of the lower modal group, and reproductive investment was considerably greater in the upper modal group than the lower modal group. The lower modal males made up the majority of the population after the spawning period, which meant they may have few opportunities to participate in reproduction. Therefore, piscivory and cannibalism of P. chinensis appears to have increased fitness of the fish belonging to the upper modal group and greatly reduced the fitness of those belonging to the lower modal group.

scholarly journals Echoes of the hunt? An inter-continental comparison of patterns of growth and determinants of size of brown bears in Canada and Sweden.

2022 ◽  
Author(s):  
Andreas Zedrosser ◽  
Marc CAttet ◽  
Jon Swenson ◽  
Gordon Stenhouse
Keyword(s):  
Population Density ◽  
Body Length ◽  
Life Histories ◽  
Life History Traits ◽  
Reproductive Investment ◽  
Negative Effects ◽  
Brown Bears ◽  
Positive Effects ◽  
The Past ◽  
The Difference

Comparing life history traits among populations that have been separated genetically for several hundred thousand years, but live in similar habitats on different continents, may help us understand how ecological and anthropomorphic factors shape life histories. We compared patterns of growth in body length and mass, and the influence of population density, habitat quality (NDVI), and reproduction on age-specific length and mass of male and female brown bears between Alberta, Canada, and Sweden. We found that Swedish females were significantly smaller in both length and mass than Alberta females. Swedish females also reached primiparity earlier and at a smaller mass and length. However, there were no continental differences in the patterns of growth in males. We found strong positive effects of NDVI, but only weak negative effects of population density on female mass and length in both areas. Generally, especially mass of Alberta females was more strongly affected by NDVI and density than for Swedish females. Reproduction had stronger negative effects on female mass in Alberta than in Sweden. We found no effects of NDVI and population density on male mass and body length in both areas. The larger variation in female growth and size between the areas, in contrast to males, may be related to differences in female reproductive investment due to differences in population trends, i.e., earlier reproduction in increasing populations or populations below carrying capacity, or to different selection pressures in the past, potentially due to human persecution. Swedish females exhibited characteristics typical of increasing populations, whereas Alberta females exhibited characteristics typical of stable or decreasing populations. The difference in reproduction investment means that Swedish bears can be harvested at higher rates, whereas Alberta bears must be managed more conservatively.

scholarly journals Plasticity in life history traits of a cyprinid fish in an intermittent river

2019 ◽  
pp. 25 ◽  
Author(s):  
Maria Glarou ◽  
Aikaterini Vourka ◽  
Leonidas Vardakas ◽  
Argyro Andriopoulou ◽  
Nikolaos Skoulikidis ◽  
...  
Keyword(s):  
Life History Traits ◽  
Prey Availability ◽  
Reproductive Investment ◽  
Liver Weight ◽  
Reproductive Period ◽  
The Body ◽  
Feeding Intensity ◽  
Intermittent Rivers ◽  
Flooding And Drying ◽  
Intermittent River

The extreme seasonal environmental variation of intermittent rivers has a profound effect on freshwater fish communities. Yet, few studies have examined the consequences of the seasonal cycles of flooding and drying to fish condition and reproduction in these ecosystems. In this study, we compared the body condition, reproduction and diet of two chub populations from two adjacent sites (a perennial and an intermittent site) on the main stem of a Mediterranean river (Evrotas River, S. Greece). The study was conducted in spring 2017, three months after flow resumption and before the onset of chub reproductive period. Condition (net weight adjusted for length) of fish did not differ significantly between the two sites, despite lower aquatic macroinvertebrate availability at the intermittent site. Fish at the intermittent site compensated for the lower aquatic prey availability by increasing their feeding intensity and by shifting to higher terrestrial prey consumption. In addition, chub liver weight (adjusted for length) and gonadal weight (adjusted for length) were significantly higher at the intermittent site, indicating higher somatic and reproductive investment. These results highlight the resilience of fish populations inhabiting streams with extreme variation in flow, due to natural and/or anthropogenic drought.

scholarly journals Development of a Promising Fish Model (Oryzias melastigma) for Assessing Multiple Responses to Stresses in the Marine Environment

2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Sijun Dong ◽  
Mei Kang ◽  
Xinlong Wu ◽  
Ting Ye
Keyword(s):  
Marine Environment ◽  
Toxicity Testing ◽  
Literature Survey ◽  
Environmental Stressors ◽  
Steady Increase ◽  
Marine Medaka ◽  
Future Studies ◽  
Fish Model ◽  
Oryzias Melastigma ◽  
Toxicological Research

With the increasing number of contaminants in the marine environment, various experimental organisms have been “taken into labs” by investigators to find the most suitable environmentally relevant models for toxicity testing. The marine medaka,Oryzias melastigma, has a number of advantages that make it a prime candidate for these tests. Recently, many studies have been conducted on marine medaka, especially in terms of their physiological, biochemical, and molecular responses after exposure to contaminants and other environmental stressors. This review provides a literature survey highlighting the steady increase of ecotoxicological research on marine medaka, summarizes the advantages of usingO. melastigmaas a tool for toxicological research, and promotes the utilization of this organism in future studies.

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