Biology subjects

Souza, L. S.

Publications and source records attributed to Souza, L. S..

3 recordsLinked to original sources

bioRxiv2025

Endosymbiosis: metabolic trade-offs drive reproductive synchronization

Endosymbiotic relationships have fueled the evolution of complex life. The persistence of these relationships relies on coordinating the reproduction of hosts and their guests. Yet, such coordination may come at a cost, as one or both partners may need to slow their growth to synchronize. Here, we examine the fitness consequences of synchronization by using a combination of mathematical and bacterial metabolic models. Analyzing millions of putative host-guest pairings, we find that synchronization is typically costly for hosts but beneficial for guests. We show that synchronization can occur when hosts relinquish metabolic resources to guests. Given the costs to hosts, we investigate whether hosts can benefit from growing faster, at the risk of losing their endosymbionts. Our mathematical model suggests this outcome is theoretically possible, but metabolic modeling consistently indicates that synchronization increases overall fitness-- provided the formation of new endosymbioses is rare. When new relationships can readily form, the optimal strategy shifts: hosts maximize fitness by growing as fast as possible, leading to regular cycles of loss and reacquisition of their guests. Overall, our findings indicate that while synchronization is costly for hosts, it offers long-term fitness benefits in contexts where endosymbionts are not easily replaced.

evolutionary biology↗

bioRxiv2023

The best plant-guarding ants in extrafloral nectaried plants and myrmecophytes according to baiting tests

Extrafloral nectaried plants and myrmecophytes offer resources to ants that may engage in protective mutualisms. The role of different ant species in herbivore deterrence has long been analyzed by using herbivore baits, and ants are regarded as effective plant guards if they attack and/or remove the baits (mostly termites) from plants. Here, we conducted a comparative investigation on which ants display aggression toward baits, which ants are better plant guards, and which plants (extrafloral nectaried plants or myrmecophytes) are better defended by ants. Data from the literature revealed that baiting studies have been performed on 37 extrafloral nectaried plant species and 19 myrmecophytes, and have involved over 30 genera of ants. Extrafloral nectaried plants and myrmecophytes rely on specific ant fauna to defend them from herbivores. In extrafloral nectaried plants, Camponotus and Crematogaster were regarded as the best plant protectors, as they attacked baits in nearly all plants. In myrmecophytes, Azteca, Pheidole and Pseudomyrmex were the most important bait attackers. Myrmecophytes were better protected by ants, as all baits were attacked; in extrafloral nectaried plants, some ants failed to attack the baits. Plants can be patrolled by several different ants, but there is a core of ants that excel in protection, and this varies according to plant type (extrafloral nectaried plants and myrmecophytes). With this knowledge, it may be possible to label different ants as effective plant guards, to anticipate their effects on plant performance and even to understand their potential role as biological control agents.

ecology↗

bioRxiv2022

Black Queen Hypothesis, partial privatization, andquorum sensing evolution

Microorganisms produce costly cooperative goods whose benefit is partially shared with nonproducers, called mixed goods. The Black Queen Hypothesis predicts that partially privatization of benefits from the mixed goods has two major evolutionary implications. First, to favor strains producing several mixed goods over nonproducing strains. Second, to favor the maintenance of cooperative traits through different strains instead of having all cooperative traits present in a single strain (metabolic specialization). Despite the importance of quorum sensing regulation of mixed goods, it is not clear how partial privatization of benefits affects quorum sensing evolution. Here, we studied the influence of partial privatization of benefits on the evolution of quorum sensing. We developed a mathematical population genetics model of an unstructured microbial population considering four strains that differ in their ability to produce an autoinducer (quorum sensing signaling molecule) and a mixed good. Our model assumes that the production of the autoinducers and the mixed goods is constitutive and/or depends on quorum sensing. Our results suggest that partially privatized benefits cannot foster quorum sensing. This result occurs because: (1) a strain that produces both autoinducer and good (fully producing strain) cannot persist in the population; (2) the strain only producing the autoinducer and the strain producing mixed goods in response to the autoinducers cannot coexist, i.e., metabolic specialization cannot be fostered.

evolutionary biology↗