Biology subjects

Serrato-Capuchina, A.

Publications and source records attributed to Serrato-Capuchina, A..

6 recordsLinked to original sources

bioRxiv2025

Variation in response to water availability across Phlox species

Plants adapt to environmental variation both by evolving divergent trait means and by plastically adjusting trait expression in response to local conditions. While these dual strategies are essential for persistence in diverse environments, how they interact and vary across closely related species is understudied. For plants, water availability is a particularly important selective force that shapes species distributions, selects for growth habit and life history strategy, and can dictate individuals plastic expressions of trait values and reproductive success. Here, we use ecological niche modeling, field soil collections, and a controlled drought experiment to test how biogeography and evolutionary history influence responses to limited water availability in three closely related Texas annual Phlox species and their F1 hybrids. We infer that the species occupy distinct niches that diverge along a primary axis of water availably and soil moisture. Each species has a distinct vegetative growth habit that does not match broad predictions of divergence in response to water availability. Nevertheless, we find that all the species show a significant morphological response to controlled soil dry down with reduced biomass, smaller leaves, and fewer flowers, as would be predicted in a response to drought. We find that Phlox drummondii, which occupies intermediate habitats, exhibits the strongest plastic response to water limitation, despite it not having the broadest environmental niche. Additionally, most hybrids involving P. drummondii display intermediate phenotypes in both wet and dry treatments, while hybrids between P. cuspidata and P. roemeriana show phenotypes consistent with hybrid vigor. These results challenge the hypothesis that species from broader environments evolve greater plasticity. Instead, the most plastic species did not have the broadest niche, suggesting plasticity and niche breadth may evolve independently.

evolutionary biology↗

bioRxiv2025

The genetic architecture of quantitative variation in the self-incompatibility response within Phlox drummondii (Polemoniaceae)

Flowering plants display extensive variation in selfing rate, a trait with significant ecological and evolutionary consequences. Many species use genetic mechanisms to recognize and reject self-pollen (termed self-incompatibility or SI), and the loss of SI is one of the most common evolutionary transitions among flowering plants. Despite the ubiquity of transitions to self-compatibility (SC), little is known about the genetic architecture through which SC evolves. Specifically, it is important to determine if SC has a polygenic or simple genetic basis and if variation in compatibility localizes to the genomic locus causing self-pollen recognition (the "S-locus"). Phlox drummondii (Polemoniaceae) has been a model system for exploring mating system evolution and expresses extensive range-wide variation in the SI response. Here we investigate the genetic architecture of SC variants segregating within this otherwise SI species. Using multiple independent crosses, we uncover numerous QTLs associated with intraspecific variation in SI, consistent with a polygenic genetic architecture. While some QTLs overlap across mapping experiments, other QTLs are unique, suggesting that multiple genetic routes to SC exist. Through these crossing experiments, we demonstrate that P. drummondii has a sporophytic SI system, suggesting that an independent evolution of SI occurred in the lineage containing Phlox. We map this novel S-locus and find that the genomic region containing the S-locus is associated with intraspecific variation in SI in one of the three mapping populations. Although further work is necessary to clarify the conditions under which quantitative variation in SI represents a transitional pathway to complete SC, our study reveals the underlying genetic architecture upon which selection could act to drive this frequent and evolutionarily significant transition.

plant biology↗

bioRxiv2023

The spread of Aedes albopictus in the islands of Sao Tome and Principe

The mosquito Aedes albopictus is a vector species of Dengue, yellow fever, and Zika among other diseases. The species originated in Southeast Asia and has spread widely and rapidly in the last century. The species has been reported in localities from the Gulf of Guinea since the early 2000s, but systematic sampling has been scant. We sampled Ae. albopictus between 2013 and 2023 across the altitudinal gradient in Sao Tome and found that the species was present in all sampled years at altitudes up to 680 meters. We also find some evidence of increases in proportional representation compared to Ae. aegypti over time. We report the presence of the species in Principe for the first time, suggesting that the range of Ae. albopictus is larger than previously thought. Finally, we use bioclimatic niche modeling to infer the potential range of Ae. albopictus and infer that the species has the potential to spread across a large portion of Sao Tome and Principe. Our results suggest that Ae. albopictus has established itself as a resident species of the islands of the Gulf of Guinea and should be incorporated into the list of potential vectors that need to be surveyed and controlled.

zoology↗

bioRxiv2021

Population structure and introgression among recently differentiated Drosophila melanogaster populations

Despite a century of genetic analysis, the evolutionary history underlying patterns of exceptional genetic and phenotypic variation in the model organism Drosophila melanogaster remains poorly understood. How genetic and phenotypic variation is partitioned across the range of D. melanogaster, particularly in its putative ancestral range in Subtropical Africa, remains unresolved. Here, we assess patterns of population genetic structure, admixture, mate preference, and genetic incompatibility across a global sample, including 174 new accessions from remote regions within Subtropical Africa. While almost all Out of Africa genomes correspond to a single genetic ancestry, different geographic regions within Africa contain multiple ancestries, with substantial cryptic diversity in Subtropical Africa. Admixture between distinct lineages is prevalent across the range, but admixture rates vary between lineages. Female mate choice within Subtropical Africa is highly polymorphic and behavioral types are not monophyletic. The genetic architecture of mate choice is highly polygenic, including loci associated with neurological development, behavior, olfactory perception, and learning. Finally, we discovered that many segregating putative incompatibilities likely evolved during or after expansion out of Africa. This work contributes to our understanding of the evolutionary history of a key model system, and provides insight into the distribution of polymorphic reproductive barriers.

evolutionary biology↗

bioRxiv2020

P-elements strengthen reproductive isolation within the Drosophila simulans species complex

Determining mechanisms that underlie reproductive isolation is key to understanding how species boundaries are maintained in nature. Transposable elements (TEs) are ubiquitous across eukaryotic genomes. However, the role of TEs in modulating the strength of reproductive isolation between species is poorly understood. Several species of Drosophila have been found to harbor P-elements (PEs), yet only D. simulans is known to be polymorphic for their presence in wild populations. PEs can cause reproductive isolation between PE-containing (P) and PE-lacking (M) lineages of the same species. However, it is unclear whether they also contribute to the magnitude of reproductive isolation between species. Here, we use the simulans species complex to assess whether differences in PE status between D. simulans and its sister species, which do not harbor PEs, contribute to multiple barriers to gene flow between species. We show that crosses involving a P D. simulans father and an M mother from a sister species exhibit lower F1 female fecundity than crosses involving an M D. simulans father and an M sister-species mother. Our results suggest that the presence of PEs in a species can strengthen isolation from its sister species, providing evidence that transposable elements can play a role in reproductive isolation and facilitate the process of speciation. IMPACT SUMMARYTransposable elements (TEs) are repetitive genetic units found across the tree of life. They play a fundamental role on the evolution of each species genome. TEs have been implicated in diversification, extinction, and the origin of novelty. However, their potential role in contributing to the maintenance of species boundaries remains largely understudied. Using whole genome sequences, we compared the relative content of TEs across the three species of the Drosophila simulans complex. We find that the presence of one TE, P-element, in D. simulans, and its absence in the sister taxa, differentiates the three species. P-elements (PEs) cause a suite of fitness defects in Drosophila pure-species individuals if their father has PEs but their mother does not, a phenomenon known as hybrid dysgenesis (HD). We thus studied the possibility that PEs enhance isolation between recently-diverged species. In particular, we studied whether the progeny from interspecific crosses were more prone to suffer from HD than pure species. We found that the presence of paternal PEs reduces hybrid female fecundity, mirroring observations of HD described within species. The effect of PEs is stronger in the interspecific hybrids than in pure species. Our results suggest that PEs can strengthen reproductive isolation in well-formed sister species that still hybridize in nature and pose the question of whether other TEs are involved in the formation of species or in their persistence over time.

evolutionary biology↗

bioRxiv2020

Pure species discriminate against hybrids in the Drosophila melanogaster species subgroup

Introgression, the exchange of alleles between species, is a common event in nature. This transfer of alleles between species must happen through fertile hybrids. Characterizing the traits that cause defects in hybrids illuminate how and when gene flow is expected to occur. Inviability and sterility are extreme examples of fitness reductions but are not the only type of defects in hybrids. Some traits specific to hybrids are more subtle but are important to determine their fitness. In this report, we study whether F1 hybrids between two species pairs of Drosophila are as attractive as the parental species. We find that in both species pairs, the sexual attractiveness of the F1 hybrids is reduced and that pure species discriminate strongly against them. We also find that the cuticular hydrocarbon (CHC) profile of the hybrids is intermediate between the parental species. Perfuming experiments show that modifying the CHC profile of the hybrids to resemble pure species improves their chances of mating. Our results show that behavioral discrimination against hybrids might be an important component of the persistence of species that can hybridize.

evolutionary biology↗