ARTICLE | doi:10.20944/preprints201808.0508.v1
Subject: Biology, Ecology Keywords: sexual selection, sexual conflicts, contemporary evolution, mate choice, mating systems, mating strategies.
Online: 29 August 2018 (16:19:12 CEST)
The study of eco-evolutionary feedbacks is in clear recent expansion. However, most studies concern predator-prey and host-parasite interactions, while the analysis of eco-evolutionary feedbacks involving sexual interactions is lagging behind. This is at odds with the potential of these interactions to engage in such processes. Indeed, there is now ample evidence that sexual selection is affected by ecological change. There is also evidence that sexual selection traits evolve rapidly, which may modify the ecological context of species, and thus the selection pressures they will be exposed to. Here, we first set a clear distinction between processes in which ecology drives evolution and those in which the contemporary evolution of populations may change their ecology, depending on which traits act as drivers and objects of change. We then review evidence for these processes and discuss examples of closed eco-evolutionary feedbacks in an attempt to understand how we can tear this loop apart. We suggest that a better understanding of eco-evolutionary feedbacks of sexual selection may help us understand the effects of sexual selection on the rate of adaptation, speciation, and extinction, and thus foster future research in this area.
ARTICLE | doi:10.20944/preprints202111.0122.v1
Subject: Keywords: Dinoflagellate; Saxitoxins; Mating systems; Resting cysts; PSP outbreak; Chilean Patagonia
Online: 5 November 2021 (12:57:35 CET)
The bloom-forming toxic dinoflagellate Alexandrium catenella was first detected in Southern Chile (39.5–55°S) 50 years ago and is responsible for most of the area’s cases of paralytic shellfish poisoning (PSP). Given the complex life history of A. catenella, which includes benthic sexual cysts, in this study we examined the potential link between latitude, toxicity, and sexual compatibility. Nine clones isolated from Chilean Patagonia were used in self- and out-crosses in all possible combinations (n=45). The effect of latitude on toxicity, reproductive success indexes, and cyst production was also determined. Although the toxin profiles were similar for all strains, consisting of C1, C2, GTX4, GTX1, GTX3, and NeoSTX, a latitudinal gradient was determined for their proportions (%) and content per cell (pg cell−1), with the more toxic strains occurring in the north (−40.6°S). Reproductive success also showed a latitudinal tendency and was lower in the north. None of the self-crosses yielded resting cysts. Rather, the production of resting cysts was highest in pairings of clones separated by distances of 1000–1650km. Our results contribute to a better understanding of PSP outbreaks in the region and demonstrate the importance of resting cysts in fueling new toxic events. They also provide additional evidence that the introduction of strains from neighboring regions is a cause for concern.
ARTICLE | doi:10.20944/preprints202101.0338.v1
Subject: Biology, Anatomy & Morphology Keywords: animal personality; swimming activity; male mate choice; mating preferences; Poecilia reticulata
Online: 18 January 2021 (12:58:42 CET)
Mate choice that is based on behavioural traits is a common feature in the animal kingdom. Using the Trinidadian guppy, a species with mutual mate choice, we investigated whether males use female swimming activity – a behavioural trait known to differ consistently among individuals in many species – as a trait relevant for their mate choice. In a first experiment, we assessed male and female activity in an open field test alone (two repeated measures) and afterwards in heterosexual pairs (two repeated measures). In these pairs, we simultaneously assessed males’ mating efforts by counting number of sexual behaviours (courtship displays and copulation). Male and female guppies showed consistent individual differences in their swimming activity when tested both alone and in a pair, and these differences were maintained across both test situations. When controlling for male swimming behaviour and both male and female body size, males performed more courtship displays towards females with higher swimming activity. In a second experiment, we tested for a directional male preference for swimming activity by presenting males video animations of low and high active females in a dichotomous choice test. In congruence with experiment 1, we found males to spend significantly more time in association with the high active female stimulus. Both experiments thus point towards a directional male preference for higher activity levels in females. We discuss the adaptive significance of this preference as activity patterns might indicate individual female quality, health or reproductive state while, mechanistically, females that are more active might be more detectable to males as well.
HYPOTHESIS | doi:10.20944/preprints202010.0518.v1
Subject: Biology, Plant Sciences Keywords: alternation of generations; fertilization; gametophyte; mating; meiosis; plant sexual reproduction; sporophyte
Online: 26 October 2020 (11:49:53 CET)
The current plant two-sex model makes the assumption that there are only two sexual reproductive states: male and female. However, the application of this model to the plant alternation of generations requires the subtle redefinition of several common terms related to sexual reproduction, which also seems to obscure aspects of one or the other plant generation: For instance, the homosporous sporophytic plant is treated as being “asexual,” and the gametophytes of angiosperms treated like mere gametes. In contrast, the proposal is made that the sporophytes of homosporous plants are indeed sexual reproductive organisms, as are the gametophytes of heterosporous plants. This view requires the expansion of the number of sexual reproductive states we accept for plants, therefore a three-sex model for homosporous plants and a four-sex model for heterosporous plants are described and then contrasted with the current two-sex model. These new models allow the use of sexual reproductive terms in a manner largely similar to that seen in animals, and may better accommodate the plant alternation of generations life cycle than does the current plant two-sex model. These new three-sex and four-sex models may also help stimulate new lines of research, and examples of how they might alter our view of the flower, and may lead to new perspectives in terms of sexual determination, are presented. Thus it is suggested that plants have more than merely two sexual reproductive states, and that recognition of this may promote our study and understanding of plants.
REVIEW | doi:10.20944/preprints202001.0344.v1
Subject: Biology, Ecology Keywords: entomology; foraging; movement; migration; behaviour; morphology; mating; reproduction; fecundity; range expansion
Online: 29 January 2020 (04:09:55 CET)
Dispersal represents a key life-history trait with several implications for the fitness of organisms, population dynamics and resilience, local adaptation, meta-population dynamics, range shifting and biological invasions. Plastic and evolutionary changes of dispersal traits have been intensively studied over the past decades in entomology, in particular in wing-dimorphic insects for which literature reviews are available. Importantly, dispersal polymorphism also exists in wing-monomorphic and wingless insects, and except for butterflies, fewer syntheses are available. In this perspective, by integrating the very last research in the fast moving field of insect dispersal ecology, this review article provides an overview of our current knowledge of dispersal polymorphism in insects. After having provided a definition of the main terms characterising insects’ movements, some of the most often used experimental methodologies for the separation of dispersers and residents in wing-monomorphic and wingless insects are presented. The existing knowledge on the morphological and life-history trait differences between resident and disperser phenotypes is then synthetized. The fourth part examines the effects of range expansion on dispersal traits and performance, in particular for insects from range edges and invasion fronts. Finally, some research perspectives are proposed in the last part of the review.
ARTICLE | doi:10.20944/preprints202001.0321.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: late blight; mating type; mefenoxam; metalaxyl; potato; SSR genotyping; race structure; tomato
Online: 27 January 2020 (07:28:44 CET)
Late blight caused by the oomycete pathogen Phytophthora infestans is a devastating disease of potato and tomato worldwide, including Israel. The population structure of this pathogen was monitored in potato and tomato fields in Israel during a 36-year period of 1983-2019. Isolates of the pathogen were tested for sensitivity to phenylamide fungicides, mating type, race structure, and genotype. The phenotypic and genotypic structure of the population from potato have changed greatly from one year to another, from one season to the next, within a season and within a single field. Major changes also occurred in the population collected from tomato crops. The mechanisms driving these multiple changes and the heterogeneous nature of the population in Israel are shown to derive from multiple migration events of the pathogen via seed tubers from Europe and from fitness-driven selection processes.
REVIEW | doi:10.20944/preprints202009.0091.v1
Subject: Life Sciences, Other Keywords: Evolutionary dynamics; life-history stages; mating systems; biotic interactions; climatic variability; ecological genomics
Online: 4 September 2020 (08:13:40 CEST)
Contemporary climate change is exposing plant populations to novel combinations of temperatures, drought stress, [CO2] and other abiotic and biotic conditions. These changes are rapidly disrupting the evolutionary dynamics of plants. Despite the multifactorial nature of climate change, most studies typically manipulate only one climatic factor. In this opinion piece, we seek to explore how climate change factors interact with each other and with biotic pressures to alter evolutionary processes. We first explore the ramifications of climate change for key life history stages (germination, growth and reproduction). We then examine how mating system variation influences population persistence under rapid environmental change and propose that mixed mating could be advantageous in future climates. Furthermore, we discuss how spatial and temporal mismatches between plants and their mutualists and antagonists could promote or constrain adaptive responses to climate change. For example, plant-virus interactions vary from highly pathogenic to mildly facilitative, and are partly mediated by temperature, moisture availability and [CO2]. Will host plants exposed to novel, stressful abiotic conditions be more susceptible to viral pathogens? Finally, we propose novel experimental approaches that could illuminate how plants will cope with unprecedented global change, such as resurrection studies combined with experimental evolution, genomics or epigenetics.
REVIEW | doi:10.20944/preprints202301.0461.v1
Subject: Life Sciences, Microbiology Keywords: Cryptococcus; transcription factor; thermotolerance; virulence factors; antifungal; oxidative and osmotic stress; capsule; melanin; monokaryotic fruiting; mating and filamentation
Online: 26 January 2023 (02:54:41 CET)
Transcription factors are diverse intracellular proteins facilitating cellular responses to inducing factors via gene expression. Regulatory signalling cascades from the membrane proteins (sensors) to transcription factors (effectors) are paramount to accurate phenotypic display against external factors. This review examines several transcription factors germane to Cryptococcus (C.) neoformans adaptation and survival for human infection. These opportunistic pathogenic single-cell yeasts (fungi) possess several gene duplications and peculiar membrane proteins due to adaptive phenotypes and morphological plasticity. Consequently, hundreds of responsible pleiotropic genes have been studied to understand how these genes are induced, regulated, and coordinated. However, these findings are sparsely converged and interlinked, making it cumbersome to relate one gene to the other or group them by their functions. We reviewed several wide-ranging transcriptional analysis works associated with C. neoformans into comparable phenotypic traits that necessitate adaptation, survival, and human infection. We present a robust work that addresses several transcription factors and their inducing factors. Lastly, we converge, link, and group several of these factors according to their multifunctional expression pattern. We also provide adequate information on certain genes critical to this fungus, which could be explored pharmaceutically in drug targeting for more effective antifungal management.