Biology subjects

Plenet, S.

Publications and source records attributed to Plenet, S..

5 recordsLinked to original sources

bioRxiv2025

How does the somatic state influence plastic responses to predator cues within- and across generations?

The main dilemma facing prey is how to reduce predation risk while acquiring resources. Phenotypic plasticity, by modulating traits for acquiring resources and for defences, is a key process driving this trade-off. While there is ample evidence that predator-induced within-generational plasticity depends on resources, the relationship between resources and predator-induced transgenerational plasticity remains understudied. This study investigated how predator exposure and resource availability influence within- and trans-generational plasticity. We based our predictions on theories related to information- and state-based plasticity, two kinds of plasticity occurring in response to environmental information or alteration affecting somatic state, respectively. We conducted a two-generation laboratory experiment in the freshwater snail Physa acuta, manipulating predator cues and resource availability. Our results revealed that both types of plasticity participate in shaping the within- and transgenerational responses. Within a generation, the limited resource decreased the somatic state but did not constrain the defences. Across generations, the poor parental state decreased the offspring state even in high resource, which in turn decreased the absolute levels of their defences but increased their investment in reproduction. These results highlight the importance to integrate informational and state-based effects across generations to provide a more complete understanding of prey responses to predators.

ecology↗

bioRxiv2025

Cannot be male without complex I? Alteration in cellular metabolism involved in cytoplasmic male sterility in snail Physa acuta

Cytoplasmic male sterility (CMS) is a well-known example of mitonuclear genetic conflict over sex determination in hermaphrodite plants, where mitochondrial genes maternally inherited sterilize the male function while biparental inherited nuclear genes restore it. CMS has been recently discovered in wild animals, in the freshwater snail Physa acuta. In this species, CMS is associated with two extremely divergent mitogenomes D and K compared to the classical mitogenome N. D individuals are male-steriles, while male fertility is restored in K individuals. We hypothesized that the extreme divergence of mitogenomes associated with CMS can impact mitochondrial aerobic metabolism, a necessary process in eukaryotic organisms by which energy is transduced from food to ATP. Our results suggest that CMS might be associated with an alteration of co-encoded complex I in D male-sterile individuals, although partly compensated by the nuclear-encoded complex II. K restored hermaphrodites have an unaffected complex I respiration, but exhibit higher mitochondrial proton leak and higher relative anaerobic contribution to cellular metabolism, suggesting an energy cost of bearing CMS and restorer genes, which could underlie the reduced growth of K mitotype. How complex I alteration might induce male-sterility remains to be determined, but could be linked to oxidative stress or a defect in ATP-synthesis rate.

evolutionary biology↗

bioRxiv2024

Transcriptomic bases of within- and trans-generational predator-induced plasticity in the freshwater snail Physa acuta

Inducible defences in response to predation risk are a well-known example of adaptive phenotypic plasticity. Although inducible defences have been studied mainly within a generation (within-generational plasticity), there is now clear evidence that ancestral exposure to predation risk can influence the defences expressed by offspring, even if they have not been exposed themselves (transgenerational plasticity). The molecular mechanisms allowing the transmission of environmental information across generations are not well understood. In this study, we combined measures of antipredator responses (behavioural and morphological) with transcriptomic investigations across two generations in the freshwater snail Physa acuta. We hypothesised that both within- and transgenerational plasticity would induce phenotypic changes associated with differential gene expression. Our results confirmed within- and transgenerational plasticity: F1 snails respond to predator-cue exposure by increasing escape behaviour, reducing shell length, and developing thicker and slenderer shells, whereas F2 snails from exposed parents have longer and thicker shells with narrower apertures. Within- and transgenerational plasticity were accompanied by the differential expression of 112 genes (101 up- and 11 downregulated) and 23 differentially expressed genes (17 up- and 6 downregulated), respectively. Within- and transgenerational plasticity did not share common differentially expressed genes, but the associated molecular functions, involving metabolism and transcription regulation, were similar. These results suggest that predator-induced within-generational plasticity and transgenerational plasticity may result from different genomic pathways and may evolve independently.

evolutionary biology↗

bioRxiv2024

Temperature-dependant benefits and costs of cytoplasmic male sterility in snail Physa acuta

Cytoplasmic male sterility (CMS) originates from a mito-nuclear conflict where mitochondrial genes induce male sterility and nuclear genes restore male fertility in hermaphrodites. The first observation of CMS in animals was reported recently in the freshwater snail Physa acuta where it is associated with two extremes divergent mitotypes D and K. The D individuals are male-sterile while male-fertility is restored by nuclear genes in K and are found mixed with the most common male-fertile N mitotype in natural populations (i.e., gynodioecy). We compared male and female fitness, growth rate, and metabolism between the three mitotypes at two temperatures as this factor influences CMS in gynodioecious plants via alteration of mitochondrial functioning. Temperature did not affect male-sterility which depended only on the mitotype and the presence of restorers. Our results provided evidence that CMS is beneficial to female fitness in the absence of restorers, while it is costly in their presence, fulfilling a key theoretical condition for the long-term maintenance of gynodioecy. Fitness benefits and costs are mediated by differences in body mass and enhanced at cold temperature suggesting that the system dynamics may vary according to thermal conditions in nature.

evolutionary biology↗

bioRxiv2019

How past exposure to predation affects personality and behavioural plasticity?

When behaviour is observed multiple times on animals from the same population, between-individual difference in mean behaviour (personality) and in behavioural plasticity are often reported. While the developmental environment might explain such an individual difference, the effect of parental environment is still unexplored -a surprising observation as parental carry-over effect are now well-known to influence the average phenotype and plastic responses of offspring-. We tested whether parental and developmental exposure to predator cues impacted the immediate behavioural predator-induced response in the snail Physa acuta at both mean level (average response) and individual level (between-individual variation). Two generations of snails were reared in laboratory without or with exposure to predator cues. Then, escape behaviour was repeatedly assessed on adult snails in the presence or absence of predator cues. Both parental and developmental exposure to predator cues acted additively towards a lower average behavioural plasticity. At the individual level, developmental exposure induced higher differentiation in personality trait but not in behavioural plasticity while parental environment did not influence the between-individual differences. These results highlight that past environments can strongly influence behaviour at the population level and that they should be taken into consideration when investigating why individuals differ in behaviour.

animal behavior and cognition↗