Biology subjects

Antunes, M. A.

Publications and source records attributed to Antunes, M. A..

4 recordsLinked to original sources

bioRxiv2025

RT-qPCR Validation of Candidate Genes Underlying Thermal Adaptation in Drosophila subobscura

Understanding the genetic basis of thermal adaptation is essential in the face of global climate change. In this study, we validate candidate genes implicated in thermal adaptation previously identified through RNA-seq analysis of Drosophila subobscura populations experimentally evolved under a progressive warming regime. Using RT-qPCR, we assessed the directionality of gene expression changes--up- or downregulation--across warming and control populations from two latitudinal origins. Out of 27 candidate gene tests, 33.3% showed consistent expression patterns between RNA-seq and RT-qPCR. Our results suggest that effect size, rather than expression level alone, is a key factor driving successful validation. This should be considered when interpreting whole-transcriptome data, which can yield many candidate genes. Future studies should examine how different log2 fold-change thresholds between populations relate to the success rate of validating RNA-seq differential expression results, in order to improve the reliability of candidate gene lists.

evolutionary biology↗

bioRxiv2025

Long-term laboratory Drosophila populations prefer ancestral nutritional cues from the environment

Plasticity can help populations cope with environmental changes namely by exploring different ecological niches. Addressing plasticity for nutritional responses in a range of fruit hosts potentially used by Drosophila may be essential in predicting the capacity of insects to colonize new environments or return to ancestral ones. Here we test for differences in oviposition performance, reproductive success and juvenile viability in different host fruits in the colonizing species Drosophila subobscura Collin, and compare them with those of the laboratory maintenance medium to which populations adapted for [~]150 generations. We question: does Drosophila subobscura show plasticity associated with different fruit hosts? Is performance better in the long-term maintenance (control) medium? We observed a higher fecundity, reproductive success and juvenile viability of flies maintained in the fruit media versus the control, but no differences between fruits. Our experiment shows that long-term lab populations of Drosophila subobscura can still assess environmental cues of new substrates allowing for flexible adaptive plasticity to occur through increased fecundity and reproductive success in fruit hosts relative to the control conditions. Importantly, this ability was not lost during long-term evolution in a benign, homogeneous environment. Furthermore, the high performance across fruits reinforces its status as a generalist species and further attests its potential to colonize different ecological settings.

ecology↗

bioRxiv2024

Monandrous flies do remate: plastic and evolutionary consequences of heat exposure on mating behaviour and fertility in Drosophila subobscura

Recent work has reinforced the importance of fertility in predicting population persistence under global warming, especially male fertility. However, most studies on mating and reproductive performance have used as model organism polyandrous species, remaining unclear if and how will monandrous species respond. This is unfortunate as one could expect monandrous species to be particularly susceptible, given their inability to use sperm from multiple males to prevent reduced progeny production due to male sterility. It could be that monandrous females can overcome this toll in fertility by plastically changing their mating rate, or that monandrous populations evolve the ability to remate upon repeated exposure to heat. To test this, we studied the real-time evolution as well as the thermal plastic response of two geographically distinct populations of the monandrous species Drosophila subobscura after 45 generations evolving under a warming scenario. We assessed the impact of heat on male mating behaviour and fertility, as well as the impact of reduced male fertility on female mating behaviour and fertility. We found that in males the toll in mating behaviour due to heat can be recovered with time, whereas that in reproductive success cannot. On the other hand, females exposed to heat-stressed males significantly increased their remating rate, allowing to recover considerably their own reproductive success. Interestingly, most responses were plastic, with no striking effect of adaptation to warming nor of geographical origin. Our work brings new insights into the effects of heat on monandrous species and establishes a model to study how a shift in mating system may affect species ability to respond to climate change.

evolutionary biology↗

bioRxiv2024

Long-term dynamics of adaptation to a warming environment is dependent on historical background

Global warming is leading to worldwide biodiversity decline at a fast pace. Evolutionary responses may be crucial in allowing organisms to cope with prolonged effects of climate change. This urges the need for a better understanding of the dynamics of adaptation to warming environments. In particular, addressing how reproductive success evolves in deteriorating environments is extremely relevant, as this trait is more likely constrained at lower temperatures than upper physiological thermal limits. Experimental evolution under a warming environment can elucidate the potential of populations to respond to rapid environmental changes. The few studies following such framework lack analysis of long-term response. We here focus on the long-term thermal evolution of two Drosophila subobscura populations, from different European latitudes, under warming temperatures. We estimated the reproductive success of these populations in two test environments: the ancestral (control) and the warming environment after 39 and 52 generations of thermal evolution. We found that a relevant long-term adaptive response to warming temperatures can occur, but the pace of such response is slow. In addition, we observed contrasting responses in the ancestral environmental and differences in the evolutionary dynamics between populations of distinct histories, with those originally from higher latitude only showing an adaptive response under the to the warming environment regime in at a later generation. This study reinforces the need for long-term evolution experiments to fully reveal the potential for thermal response. It also highlights that the scrutiny of several populations in this context is needed for a measure of variation within a species. Accounting for these sources of variation - both temporal and spatial - will allow for more robust assessments of climate change responses.

evolutionary biology↗