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Ferdy, J.-B.

Publications and source records attributed to Ferdy, J.-B..

9 recordsLinked to original sources
bioRxiv2026

Seminal fluid proteins can mitigate sexual conflict: the case of remating in insects

Males during mating never transfer just sperm; to the best of our knowledge, they always deliver a rich seminal fluid as well. The proteins in the seminal fluid have an important sperm supporting role, but they also cause changes in the female physiology and can impose a mating cost. The associated costs and delay in the time of remating, lead to the view that those proteins evolved primarily due to sexual conflict and delay female remating beyond the optimal rate. To examine the role of seminal fluid proteins in sexual conflict we use a mathematical model of reproductive physiology, informed by the accumulated knowledge on Drosophila melanogaster. In accordance with the theory, we find that males always benefit from inducing longer remating intervals in females. But, we also find that this conflict is reduced when female reproduction is regulated by the male proteins. Without seminal fluid proteins females have a single, well-defined, optimal remating rate. However, when seminal proteins are used to regulate females reproduction, females can reach the same offspring production for a range of mating intervals. This wider range of possible remating times could provide females with a buffer against uncertain mating opportunity. It could also allow females to be more selective on male quality, by reducing the cost associated with delaying remating. Our results suggest that, while there is a conflict over the remating rate, seminal fluid proteins reduce its intensity, highlighting their role in aligning the interests of both sexes.

evolutionary biology↗
bioRxiv2025

The role of fecundity dynamics and time of injury for femalereproductive fitness

Animals have a wide range of reproductive strategies and change how they produce offspring as a function of their age, environment, risk of predation or starvation, and as a result of trade-offs with other life history traits. In turn, these temporal patterns of reproduction, or fecundity dynamics, will determine how vulnerable the animal is to many of the same factors that shaped the dynamics in the first place. In this study, we tested how individual fecundity dynamics influence vulnerability of female fecundity to the deleterious environmental factors. We injured Drosophila melanogaster females at various moments during periods before and after mating. Injuries are prevalent in nature and provide a punctuated stimulus, making them particularly well suited to study their connection with the dynamics of reproduction. Our aim was to determine periods of vulnerability and impact of wounds on female fitness resulting from the change. The observed fecundity dynamics exhibited a high early peak in offspring production, suggesting that early after mating females might be particularly vulnerable to environmental conditions. However, females produced the same number of offspring, regardless of the time of injury, suggesting that fitness of female Drosophila is robust to wounds inflicted under laboratory conditions.

evolutionary biology↗
bioRxiv2025

Gene-Culture Coevolution Favours the Emergence of Traditions in Mate Choice through Conformist Social Learning

The emergence of cultural traditions has long been considered to depend on sophisticated social learning mechanisms, particularly conformist transmission exhibiting a disproportionate bias towards majority behaviours. We challenge this assumption by demonstrating that gene-culture coevolutionary dynamics can fundamentally alter the conditions required for tradition formation, especially in the context of mate choice. Using simulation models of mate choice where female preferences are socially transmitted and male traits are genetically inherited, we show that the interaction between cultural and genetic transmission creates novel evolutionary dynamics. In a first model (the Cultural Model) representing classical cultural evolution scenarios, we show that traditions emerge only when conformity disproportionately amplifies majority behaviours. In a second model (the Gene-Culture Model), we introduce a distinction between learned behaviours and realized behaviours and show that when mate choice depends on both conformist learning and male trait availability, even simple social learning strategies can establish persistent traditions. In this context, majority exaggeration is no longer a necessary property of social learning for traditions to arise. This occurs because positive frequency-dependent interactions between preference and trait dynamics provide an additional mechanism that reinforces majority behaviours beyond conformist learning. Our findings have broader implications for cultural evolution theory, suggesting that many behaviours that depend on resource availability may exhibit tradition-like patterns under less stringent social learning conditions than previously assumed. By distinguishing between preference and choice, and demonstrating the importance of gene-culture interactions, this study advocates for more integrated approaches to understanding cultural evolution that consider the interplay between multiple inheritance systems.

evolutionary biology↗
bioRxiv2024

Can seminal fluid proteins be honest signals of sperm availability?

Seminal fluid proteins (Sfps) are produced by males, yet they have significant effects on female physiology and behaviour. Sfps are often viewed as a mechanism for males to manipulate female reproductive behaviours, but despite many studies identifying their varied effects and their molecular underpinnings, the ways males and females use Sfps remain unclear. In the most studied case of Drosophila melanogaster particular peptides within the seminal fluid have been identified to guide female reproduction: sex peptide (SP, Acp70A) is known to induce changes in egg production, oviposition and remating and is attached to sperm and continuously supplied for days after mating, while ovulation inducing peptide, ovulin (Acp26Aa), is a free peptide with only short term effects after mating. Using a biologically informed model we show how these peptides can synchronize sperm and egg release, hence reducing the number of unfertilized eggs a female lays. We further show that the exhaustion of SP might be the key signal of this synchronization. Finally, we demonstrate that sexual conflict over the regulation of female reproductive physiology by Sfps should be limited, with the primary conflict probably centring around the regulation of remating behaviour.

evolutionary biology↗
bioRxiv2022

A selective bottleneck during host entry drives the evolution of new legume symbionts

During the emergence of new host-microbe symbioses, multiple selective pressures-acting at the different steps of the microbial life cycle-shape the phenotypic traits that jointly determine microbial fitness. However, the relative contribution of these different selective pressures to the adaptive trajectories of microbial symbionts are still poorly known. Here we characterized the dynamics of phenotypic adaptation and its underlying genetic bases during the experimental evolution of a plant pathogenic bacterium into a legume symbiont. We observed that fast adaptation was predominantly driven by selection acting on competitiveness for host entry, which outweighed selection acting on within-host proliferation. Whole-population sequencing of evolved bacteria revealed that phenotypic adaptation was supported by the continuous accumulation of new mutations and the sequential sweeps of cohorts of mutations with similar temporal trajectories. The identification of adaptive mutations within the fixed mutational cohorts showed that all of them improved competitiveness for host entry, while only a subset of those also improved within host proliferation. Computer simulations predict that this effect emerges from the presence of a strong selective bottleneck at host entry. Together, these results show how selective bottlenecks can alter the relative influence of selective pressures acting during bacterial adaptation to multistep infection processes.

evolutionary biology↗
bioRxiv2020

Step-specific adaptation and trade-off over the course of an infection by GASP-mutation small colony variants

During an infection, parasites face a succession of challenges, each decisive for disease outcome. The diversity of challenges requires a series of parasite adaptations to successfully multiply and transmit from host to host. Thus, the pathogen genotypes which succeed during one step might be counter-selected in later stages of the infection. Using the bacteria Xenorhabdus nematophila and adult Drosophila melanogaster as hosts, we showed that such step-specific adaptations, here linked to GASP mutations in the X. nematophila master gene regulator lrp, exist and can trade-off with each other. We found that nonsense lrp mutations had lowered ability to resist the host immune response, while all classes of mutations in lrp were associated with a decrease in the ability to proliferate during early infection. We demonstrate that reduced proliferation of X. nematophila best explains diminished virulence in this infection model. Finally, decreased proliferation during the first step of infection is accompanied with improved proliferation during late infection, suggesting a trade-off between the adaptations to each step. Step-specific adaptations could play a crucial role in the chronic phase of infections in any diseases that show similar small colony variants (also known as SCV) to X. nematophila. ImportanceWithin-host evolution has been described in many bacterial diseases, and the genetic basis behind the adaptations stimulated a lot of interest. Yet, the studied adaptations are generally focused on antibiotic resistance, rarely on the adaptation to the environment given by the host, and the potential trade-off hindering adaptations to each step of the infection are rarely considered. Those trade-offs are key to understand intra-host evolution, and thus the dynamics of the infection. However, the understanding of these trade-offs supposes a detailed study of host-pathogen interactions at each step of the infection process, with for each step an adapted methodology. Using Drosophila melanogaster as host and the bacteria Xenorhabdus nematophila, we investigated the bacterial adaptations resulting from GASP mutations known to induce small colony variant (SCV) phenotype positively selected within-the-host over the course of an infection, and the trade-off between step-specific adaptations.

evolutionary biology↗
bioRxiv2020

Estimation of the propensity for sexual selection in a cyclical parthenogen

Cyclical parthenogenesis is a widespread reproductive strategy in which organisms go through one or multiple rounds of clonal reproduction before sexual reproduction. Because sexual reproduction is typically less common than parthenogenesis in populations of the planktonic cladoceran Daphnia magna, it is not frequently studied. Here we examine the sexual process of D. magna and its relation to sexual selection in Daphnia rockpool populations by observing natural mating in these shallow habitats where sex generally occurs throughout the summer. Although microsatellite markers were found to reveal no evidence of disassortative mating or, thus, of inbreeding avoidance, body length and infection status did reveal assortative mating, suggesting sexual selection to act. When two males mated with a single female, the larger male was observed to remain longer, possibly giving it an advantage in sperm competition. Indirect evidence points at the brood pouch as the likely site of fertilization and thus, sperm competition. Sperm length was as variable within ejaculates as it was among males from different populations. Our data provide firm evidence that sexual selection is present in this species, most likely manifesting itself through a combination of female choice and male-male competition.

evolutionary biology↗
bioRxiv2018

Changes in rearing conditions rapidly modify gut microbiota structure in Tenebrio molitor larvae

The gut microbiota of multicellular organisms has been shown to play a key role in their host biology. In mammals, it has an invariant component, responsible for establishing a mutualistic relationship with the host. It also contains a dynamic fraction which facilitates adaptation in response to changes in the environment. These features have been well described in mammals, but little is known about microbiota stability or plasticity in insects. We assessed changes in microbiota composition and structure in a reared insect after a change in rearing conditions. We reared Tenebrio molitor (Coleoptera, Tenebrioninae) larvae for five days in soil samples from two river banks and analyzed their gut microbial communities by a metabarcoding technique, using the V3-V4 region of the 16S rRNA gene and the housekeeping gene gyrB. We found that soil-reared insects had a significantly more diverse microbiota than the control insects and that insects reared in soil from different sites had significantly different microbiota. We confirmed this trend by absolute quantification of the two mains fluctuating taxonomic groups: the Enterobacteriaceae family and the Pseudomonas genus, dominant in the soil-reared insects and in the control insects, respectively. Our results suggest the existence of a resident microbiota in T. molitor gut, but indicate that rearing changes can induce rapid and profound changes in the relative abundance of some of the members of this resident microbiota.

microbiology↗