The effect of food availability on thermal stress in Daphnia magna: trade-offs among oxidative stress, somatic growth, and reproduction

There is increasing recognition that environmental nano-biological interactions in model species, and the resulting effects on progeny, are of paramount importance for nanomaterial (NM) risk assessment. In this work, Daphnia magna F0 mothers were exposed to a range of silver and titanium dioxide NMs. The key biological life history traits (survival, growth and reproduction) of the F1 intergenerations, at the first (F1B1), third (F1B3) and fifth (F1B5) broods, were investigated. Furthermore, the F1 germlines of each of the three broods were investigated over 3 more generations (up to 25 days each) in continuous or removed-from NM exposure, to identify how the length of maternal exposure affects the resulting clonal broods. Our results show how daphnids respond to NM-induced stress, and how the maternal effects show trade-offs between growth, reproduction and survivorship. The F1B1 (and following germline) had the shortest F0 maternal exposure times to the NMs, and thus were the most sensitive showing reduced size and reproductive output. The F1B3 generation had a sub-chronic maternal exposure, whereas the F1B5 generation suffered chronic maternal exposure where (in most cases) the most compensatory adaptive effects were displayed in response to the prolonged NM exposure, including enhanced neonate output and reduced gene expression. Transgenerational responses of multiple germlines showed a direct link with maternal exposure time to ‘sub-lethal’ effect concentrations of NMs (identified from standard OECDs acute toxicity tests which chronically presented as lethal) including increased survival and production of males in the F1B3 and G1B5 germlines. This information may help to fine-tune environmental risk assessments of NMs and prediction of their impacts on environmental ecology.

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Effect of food availability on the respiratory quotient of Daphnia magna

Comparative Biochemistry and Physiology Part A Physiology ◽

10.1016/0300-9629(84)90135-x ◽

1984 ◽

Vol 78 (2) ◽

pp. 221-223 ◽

Cited By ~ 15

Author(s):

Winfried Lampert ◽

Richard Bohrer

Keyword(s):

Daphnia Magna ◽

Food Availability ◽

Respiratory Quotient ◽

Effect Of Food

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Effects of food availability on larval development and inter-instar predation among larvae of Libellula lydia and Libellula luctuosa (Odonata: Anisoptera)

Canadian Journal of Zoology ◽

10.1139/z88-080 ◽

1988 ◽

Vol 66 (2) ◽

pp. 543-549 ◽

Cited By ~ 36

Author(s):

Scott A. Wissinger

Keyword(s):

Larval Development ◽

Daphnia Magna ◽

Food Availability ◽

Laboratory Experiments ◽

Larval Mortality ◽

Size Difference ◽

Head Width ◽

Larval Size ◽

Effect Of Food ◽

Predation Rates

I conducted two types of laboratory experiments with larvae of the dragonflies Libellula lydia and L. luctuosa. In one experiment I varied the number of Daphnia magna fed daily to these larvae to determine the effect of food availability on growth and survivorship. The time spent in each instar decreased dramatically with increased food availability, but the number of molts did not vary and the size at each molt was only slightly affected. Mortality was low in all but the lowest feeding treatment, despite 2- to 5-fold differences in instar duration. These results suggest that the number and size of instars are determinate in these species, and that starvation is an unlikely cause of larval mortality in nature. In a second experiment I used naturally co-occurring size combinations of L. lydia and L. luctuosa to determine how inter-odonate predation varies as a function of larval size difference. For both intra- and inter-specific combinations, (i) little or no predation occurred between larvae similar in size, (ii) some predation always occurred when larvae differed by more than two instars, and (iii) the number of larvae consumed increased dramatically as a function of instar difference. The proportional difference between the labial (gape) width of the larger instar and the head width of the smaller instar was a good estimator of inter-odonate predation rates across all instar and species combinations. Together these results suggest that the effects of inter-odonate competition and predation can be disentangled in the field by manipulating the instar structure of experimental populations.

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DNMT3.1 controls trade-offs between growth, reproduction, and life span under starved conditions in Daphnia magna

Scientific Reports ◽

10.1038/s41598-021-86578-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Nhan Duc Nguyen ◽

Tomoaki Matsuura ◽

Yasuhiko Kato ◽

Hajime Watanabe

Keyword(s):

Growth Rate ◽

Life Span ◽

Caloric Restriction ◽

Daphnia Magna ◽

Dna Methyltransferase ◽

Energy Allocation ◽

Freshwater Ecosystems ◽

Wild Type ◽

Trade Offs ◽

Growth And Reproduction

AbstractThe cladoceran crustacean Daphnia has long been a model of energy allocation studies due to its important position in the trophic cascade of freshwater ecosystems. However, the loci for controlling energy allocation between life history traits still remain unknown. Here, we report CRISPR/Cas-mediated target mutagenesis of DNA methyltransferase 3.1 (DNMT3.1) that is upregulated in response to caloric restriction in Daphnia magna. The resulting biallelic mutant is viable and did not show any change in growth rate, reproduction, and longevity under nutrient rich conditions. In contrast, under starved conditions, the growth rate of this DNMT3.1 mutant was increased but its reproduction was reciprocally reduced compared to the wild type when the growth and reproduction activities competed during a period from instar 4 to 8. The life span of this mutant was significantly shorter than that of the wild type. We also compared transcriptomes between DNMT3.1 mutant and wild type under nutrient-rich and starved conditions. Consistent with the DNMT3.1 mutant phenotypes, the starved condition led to changes in the transcriptomes of the mutant including differential expression of vitellogenin genes. In addition, we found upregulation of the I am not dead yet (INDY) ortholog, which has been known to shorten the life span in Drosophila, explaining the shorter life span of the DNMT3.1 mutant. These results establish DNMT3.1 as a key regulator for life span and energy allocation between growth and reproduction during caloric restriction. Our findings reveal how energy allocation is implemented by selective expression of a DNMT3 ortholog that is widely distributed among animals. We also infer a previously unidentified adaptation of Daphnia that invests more energy for reproduction than growth under starved conditions.

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EFFECTS OF MICROCYSTIS ON THE GROWTH AND REPRODUCTION OF DAPHNIA MAGNA

Acta Hydrobiologica Sinica ◽

10.3724/sp.j.1035.2009.61198 ◽

2010 ◽

Vol 33 (6) ◽

pp. 1198-1201

Author(s):

Xiao-Yu LI ◽

Zhi-Juan ZHANG ◽

Lei LI

Keyword(s):

Daphnia Magna ◽

Growth And Reproduction

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Phloem-Feeding Herbivores Affect Floral Development and Reproduction in the Etruscan Honeysuckle (Lonicera etrusca Santi)

Plants ◽

10.3390/plants10040815 ◽

2021 ◽

Vol 10 (4) ◽

pp. 815

Author(s):

Sandra V. Rojas-Nossa ◽

José María Sánchez ◽

Luis Navarro

Keyword(s):

Fruit Set ◽

Floral Development ◽

Seed Set ◽

Wild Populations ◽

Ecological Processes ◽

Trade Offs ◽

Complex Landscape ◽

Fruit And Seed Set ◽

Phloem Feeding ◽

Growth And Reproduction

Floral development depends on multifactor processes related to genetic, physiological, and ecological pathways. Plants respond to herbivores by activating mechanisms aimed at tolerating, compensating, or avoiding loss of biomass and nutrients, and thereby survive in a complex landscape of interactions. Thus, plants need to overcome trade-offs between development, growth, and reproduction vs. the initiation of anti-herbivore defences. This study aims to assess the frequency of phloem-feeding herbivores in wild populations of the Etruscan honeysuckle (Lonicera etrusca Santi) and study their effects on floral development and reproduction. The incidence of herbivory by the honeysuckle aphid (Hyadaphis passerinii del Guercio) was assessed in three wild populations of the Iberian Peninsula. The effect of herbivory on floral morphology, micromorphology of stigmas and pollen, floral rewards, pollination, and fruit and seed set were studied. The herbivory by aphids reduces the size of flowers and pollen. Additionally, it stops nectar synthesis and causes malformation in pollen and microstructures of stigmas, affecting pollination. As a consequence, fruit set and seed weight are reduced. This work provides evidence of the changes induced by phloem-feeding herbivores in floral development and functioning that affect the ecological processes necessary to maintain the reproductive success of plants.

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Sex ratio and life history traits at reaching sexual maturity in the dioecious shrub Fuchsia parviflora: field and common garden experiments

Journal of Tropical Ecology ◽

10.1017/s0266467421000043 ◽

2021 ◽

pp. 1-6

Author(s):

Jessica S. Ambriz ◽

Clementina González ◽

Eduardo Cuevas

Keyword(s):

Natural Population ◽

Sexual Maturity ◽

Sex Ratios ◽

Natural Populations ◽

Common Garden ◽

Common Garden Experiment ◽

Trade Offs ◽

Reproductive Biomass ◽

Common Garden Experiments ◽

Growth And Reproduction

Abstract Fuchsia parviflora is a dioecious shrub that depends on biotic pollination for reproduction. Previous studies suggest that the male plants produce more flowers, and male-biased sex ratios have been found in some natural populations. To assess whether the biased sex ratios found between genders in natural populations are present at the point at which plants reach sexual maturity, and to identify possible trade-offs between growth and reproduction, we performed a common garden experiment. Finally, to complement the information of the common garden experiment, we estimated the reproductive biomass allocation between genders in one natural population. Sex ratios at reaching sexual maturity in F. parviflora did not differ from 0.5, except in one population, which was the smallest seedling population. We found no differences between genders in terms of the probability of germination or flowering. When flowering began, female plants were taller than males and the tallest plants of both genders required more time to reach sexual maturity. Males produced significantly more flowers than females, and the number of flowers increased with plant height in both genders. Finally, in the natural population studied, the investment in reproductive biomass was seven-fold greater in female plants than in male plants. Our results showed no evidence of possible trade-offs between growth and reproduction. Despite the fact that female plants invest more in reproductive biomass, they were taller than the males after flowering, possibly at the expense of herbivory defence.

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