scholarly journals Predator cues alter the timing of developmental events in gastropod embryos

2010 ◽  
Vol 7 (2) ◽  
pp. 285-287 ◽  
Author(s):  
Simon D. Rundle ◽  
J. J. Smirthwaite ◽  
M. W. Colbert ◽  
J. I. Spicer
Keyword(s):  
Developmental Plasticity ◽  
Predator Cues ◽  
Evolutionary Pattern ◽  
Event Timing ◽  
Developmental Sequences ◽  
Radix Balthica ◽  
Species Specific ◽  
Radix Auricularia ◽  
Timing Of Onset ◽  
Egg Capsule

Heterochrony, differences in the timing of developmental events between descendent species and their ancestors, is a pervasive evolutionary pattern. However, the origins of such timing changes are still not resolved. Here we show, using sequence analysis, that exposure to predator cues altered the timing of onset of several developmental events in embryos of two closely related gastropod species: Radix balthica and Radix auricularia . These timing alterations were limited to certain events and were species-specific. Compared with controls, over half (62%) of exposed R. auricularia embryos had a later onset of body flexing and an earlier occurrence of the eyes and the heart; in R. balthica , 67 per cent of exposed embryos showed a later occurrence of mantle muscle flexing and an earlier attachment to, and crawling on, the egg capsule wall. The resultant developmental sequences in treated embryos converged, and were more similar to one another than were the sequences of the controls for both species. We conclude that biotic agents can elicit altered event timing in developing gastropod embryos. These changes were species-specific, but did not occur in all individuals. Such developmental plasticity in the timing of developmental events could be an important step in generating interspecific heterochrony.

scholarly journals Analysis of substitution rates showed that TLR5 is evolving at different rates among mammalian groups

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Ana Pinheiro ◽  
Ana Águeda-Pinto ◽  
José Melo-Ferreira ◽  
Fabiana Neves ◽  
Joana Abrantes ◽  
...  
Keyword(s):  
Substitution Rate ◽  
Relative Rate ◽  
Purifying Selection ◽  
Genetic Distances ◽  
Major Protein ◽  
Substitution Rates ◽  
Evolutionary Pattern ◽  
Branch Model ◽  
Rate Test ◽  
Species Specific

Abstract Background Toll-like receptors (TLRs) are the most widely studied innate immunity receptors responsible for recognition of invading pathogens. Among the TLR family, TLR5 is the only that senses and recognizes flagellin, the major protein of bacterial flagella. TLR5 has been reported to be under overall purifying selection in mammals, with a small proportion of codons under positive selection. However, the variation of substitution rates among major mammalian groups has been neglected. Here, we studied the evolution of TLR5 in mammals, comparing the substitution rates among groups. Results In this study we analysed the TLR5 substitution rates in Euungulata, Carnivora, Chiroptera, Primata, Rodentia and Lagomorpha, groups. For that, Tajima’s relative rate test, Bayesian inference of evolutionary rates and genetic distances were estimated with CODEML’s branch model and RELAX. The combined results showed that in the Lagomorpha, Rodentia, Carnivora and Chiroptera lineages TLR5 is evolving at a higher substitution rate. The RELAX analysis further suggested a significant relaxation of selective pressures for the Lagomorpha (K = 0.22, p < 0.01), Rodentia (K = 0.58, p < 0.01) and Chiroptera (K = 0.65, p < 0.01) lineages and for the Carnivora ancestral branches (K = 0.13, p < 0.01). Conclusions Our results show that the TLR5 substitution rate is not uniform among mammals. In fact, among the different mammal groups studied, the Lagomorpha, Rodentia, Carnivora and Chiroptera are evolving faster. This evolutionary pattern could be explained by 1) the acquisition of new functions of TLR5 in the groups with higher substitution rate, i.e. TLR5 neofunctionalization, 2) by the beginning of a TLR5 pseudogenization in these groups due to some redundancy between the TLRs genes, or 3) an arms race between TLR5 and species-specific parasites.

scholarly journals Origins and Evolutionary Patterns of the 1.688 Satellite DNA Family in Drosophila Phylogeny

2020 ◽  
Vol 10 (11) ◽  
pp. 4129-4146
Author(s):  
Leonardo G. de Lima ◽  
Stacey L. Hanlon ◽  
Jennifer L. Gerton
Keyword(s):  
Repetitive Sequences ◽  
Specific Pattern ◽  
Evolutionary Patterns ◽  
Satellite Dnas ◽  
Evolutionary Pattern ◽  
Functional Roles ◽  
Drosophila Phylogeny ◽  
Species Specific ◽  
Future Work ◽  
Eukaryotic Genomes

Satellite DNAs (satDNAs) are a ubiquitous feature of eukaryotic genomes and are usually the major components of constitutive heterochromatin. The 1.688 satDNA, also known as the 359 bp satellite, is one of the most abundant repetitive sequences in Drosophila melanogaster and has been linked to several different biological functions. We investigated the presence and evolution of the 1.688 satDNA in 16 Drosophila genomes. We find that the 1.688 satDNA family is much more ancient than previously appreciated, being shared among part of the melanogaster group that diverged from a common ancestor ∼27 Mya. We found that the 1.688 satDNA family has two major subfamilies spread throughout Drosophila phylogeny (∼360 bp and ∼190 bp). Phylogenetic analysis of ∼10,000 repeats extracted from 14 of the species revealed that the 1.688 satDNA family is present within heterochromatin and euchromatin. A high number of euchromatic repeats are gene proximal, suggesting the potential for local gene regulation. Notably, heterochromatic copies display concerted evolution and a species-specific pattern, whereas euchromatic repeats display a more typical evolutionary pattern, suggesting that chromatin domains may influence the evolution of these sequences. Overall, our data indicate the 1.688 satDNA as the most perduring satDNA family described in Drosophila phylogeny to date. Our study provides a strong foundation for future work on the functional roles of 1.688 satDNA across many Drosophila species.

Sexual morphology of male Sepsis cynipsea (Diptera: Sepsidae): lack of support for lock-and-key and sexually antagonistic morphological coevolution hypotheses

2005 ◽  
Vol 137 (5) ◽  
pp. 551-565 ◽  
Author(s):  
William G. Eberhard
Keyword(s):  
Female Choice ◽  
Alternative Hypothesis ◽  
Divergent Evolution ◽  
Abdominal Sternite ◽  
Sense Organs ◽  
Evolutionary Pattern ◽  
Wing Base ◽  
Defensive Responses ◽  
Species Specific ◽  
Male Morphology

AbstractTraits that function in male–female sexual interactions tend to diverge rapidly compared with other traits. Several hypotheses attempt to explain this evolutionary pattern. Predictions of two of these hypotheses, lock-and-key and sexually antagonistic morphological co-evolution, were tested by examining how two sets of species-specific male structures fit with female structures during courtship and copulation in the fly Sepsis cynipsea (L., 1758). Contrary to predictions of both hypotheses, neither the species-specific modifications of the male's front legs nor those of his genitalic surstyli were matched by modifications of the female structures with which they meshed (wing bases, 6th abdominal sternite); males damaged small patches of microtrichia on the female's wings with their legs, but the morphology of the female's wings and abdomen showed no sign of the defensive designs expected under antagonistic morphological co-evolution. Data regarding the alternative hypothesis of sexually antagonistic behavioral co-evolution by females in response to male morphology were less conclusive, but this hypothesis failed to explain the sustained, apparently stimulatory rhythmic squeezing by the male genitalia and the lack of female defensive responses to this squeezing. These movements of the male surstyli during copulation suggest that they function to stimulate the female. The wing base of the female has apparent sense organs near the sites contacted by the male, as expected under the alternative hypothesis of traditional female choice to explain rapid divergent evolution. The male's genitalic surstyli were also used in novel precopulatory interactions. A pair of previously undescribed processes at the bases of the surstyli probably grasp and may also rhythmically squeeze the female during copulation.

scholarly journals Inter- and intra-specific variability in δ13C and δ18O values of freshwater gastropod shells from Lake Lednica, western Poland

2017 ◽  
Vol 67 (3) ◽  
pp. 441-458 ◽  
Author(s):  
Karina Apolinarska ◽  
Mariusz Pełechaty
Keyword(s):  
Isotope Composition ◽  
Lacustrine Sediments ◽  
Carbon Isotope Composition ◽  
Freshwater Gastropod ◽  
Bithynia Tentaculata ◽  
As Species ◽  
Theodoxus Fluviatilis ◽  
Species Specific ◽  
Radix Auricularia ◽  
Δ13c And Δ18o

AbstractThis study focuses on the inter- and intra-specific variability in δ13C and δ18O values of shells and opercula of gastropods sampled live from the littoral zone of Lake Lednica, western Poland. The δ13C and δ18O values were measured in individual opercula of Bithynia tentaculata and in shells of Bithynia tentaculata, Gyraulus albus, Gyraulus crista, Lymnaea sp., Physa fontinalis, Radix auricularia, Theodoxus fluviatilis and Valvata cristata. The gastropods selected for the study are among the species most commonly found in European Quaternary lacustrine sediments. The carbon isotope composition of the gastropod shells was species-specific and the same order of species from the most to the least13C-depleted was observed at all sites sampled. Differences in shell δ13C values between species were similar at all sampling sites, thus the factors influencing shell isotopic composition were interpreted as species-specific. The δ18O values of shells were similar in all the species investigated. Significant intra-specific variability in shell δ13C and δ18O values was observed not only within the populations of Lake Lednica, which can be explained by heterogeneity of δ13C DIC, δ18O water and water temperature between the sites where macrophytes with snails attached were sampled, but also between individuals sampled from restricted areas of the lake’s bottom. The latter points to the importance of factors related to the ontogeny of individual gastropods.

scholarly journals Adrenarche in bonobos (Pan paniscus): evidence from ontogenetic changes in urinary dehydroepiandrosterone-sulfate levels

2012 ◽  
Vol 214 (1) ◽  
pp. 55-65 ◽  
Author(s):  
Verena Behringer ◽  
Gottfried Hohmann ◽  
Jeroen M G Stevens ◽  
Anja Weltring ◽  
Tobias Deschner
Keyword(s):  
Social Behavior ◽  
Pan Paniscus ◽  
Dehydroepiandrosterone Sulfate ◽  
Evolutionary Origin ◽  
Behavioral Characteristics ◽  
Physiological Changes ◽  
Ontogenetic Changes ◽  
Behavioral Traits ◽  
Species Specific ◽  
Timing Of Onset

Adrenarche is characterized by the onset of adrenal secretions of increasing amounts of dehydroepiandrosterone-sulfate (DHEA-S). While the function of adrenarche remains a matter of speculation, evidence suggests that the morphological and physiological changes related to it are restricted to humans and closely related primates. Within the primate order, adrenarche has been described only in humans and chimpanzees, but bonobos, the sister species of chimpanzees, have not yet been studied regarding the early ontogenetic changes such as adrenarche. While bonobos and chimpanzees share many morphological and behavioral characteristics, they differ in a number of behavioral traits, and there is a growing interest in terms of the physiological differences that can be linked to species-specific patterns of social behavior. In this study, we measured urinary DHEA-S levels to determine whether bonobos experience physiological changes that are indicative of adrenarche. We measured DHEA-S in urine using ELISA and analyzed its levels in the samples from 53 bonobos aged 1–18 years. Our results show that bonobos experience an increase in DHEA-S levels after 5 years of age, which is comparable with the patterns observed in humans and chimpanzees. This indicates that bonobos do undergo adrenarche and that the timing of onset is similar to that of the two Pan species. The extraction procedures described in this report demonstrate the use of urine for monitoring ontogenetic changes in DHEA-S excretion. If applicable to other species, the technique would facilitate more research on the evolutionary origin of adrenarche and other developmental processes.

scholarly journals Behaviour of freshwater snails (Radix balthica) exposed to the pharmaceutical sertraline under simulated predation risk

Ecotoxicology ◽  
2018 ◽  
Vol 27 (2) ◽  
pp. 144-153 ◽  
Author(s):  
Melanie Lea Hedgespeth ◽  
Tomasz Karasek ◽  
Johan Ahlgren ◽  
Olof Berglund ◽  
Christer Brönmark
Keyword(s):  
Predation Risk ◽  
Selective Serotonin Reuptake Inhibitors ◽  
Habitat Choice ◽  
Freshwater Snail ◽  
Predatory Fish ◽  
Interspecies Interactions ◽  
Predator Cues ◽  
Predator Attack ◽  
Radix Balthica ◽  
Fish Predators

AbstractDue to their potential for affecting the modulation of behaviour, effects of selective serotonin reuptake inhibitors (SSRIs) in the environment are particularly interesting regarding interspecies interactions and non-consumptive effects (NCEs) induced by predator cues in prey organisms. We evaluated the effects of sertraline (0.4, 40 ng/L, 40 µg/L) over 8 days on activity and habitat choice in the freshwater snail Radix balthica, on snails’ boldness in response to mechanical stimulation (simulating predator attack), and their activity/habitat choice in response to chemical cues from predatory fish. We hypothesised that sertraline exposure would detrimentally impact NCEs elicited by predator cues, increasing predation risk. Although there were no effects of sertraline on NCEs, there were observed effects of chemical cue from predatory fish on snail behaviour independent of sertraline exposure. Snails reduced their activity in which the percentage of active snails decreased by almost 50% after exposure to fish cue. Additionally, snails changed their habitat use by moving away from open (exposed) areas. The general lack of effects of sertraline on snails’ activity and other behaviours in this study is interesting considering that other SSRIs have been shown to induce changes in gastropod behaviour. This raises questions on the modes of action of various SSRIs in gastropods, as well as the potential for a trophic “mismatch” of effects between fish predators and snail prey in aquatic systems.

scholarly journals Contrasting patterns of coding and flanking region evolution in mammalian keratin associated protein-1 genes

2018 ◽  
Author(s):  
Huitong Zhou ◽  
Tina Visnovska ◽  
Hua Gong ◽  
Sebastian Schmeier ◽  
Jon Hickford ◽  
...  
Keyword(s):  
Concerted Evolution ◽  
Purifying Selection ◽  
Gene Families ◽  
Specific Protein ◽  
Common Mechanism ◽  
Dna Repeats ◽  
Coding Region ◽  
Evolutionary Patterns ◽  
Evolutionary Pattern ◽  
Species Specific

AbstractDNA repeats are common elements in eukaryotic genomes, and their multi-copy nature provides the opportunity for genetic exchange. This exchange can produce altered evolutionary patterns, including concerted evolution where within genome repeat copies are more similar to each other than to orthologous repeats in related species. Here we investigated the genetic architecture of the keratin-associated protein (KAP) gene family, KRTAP1. This family encodes proteins that are important components of hair and wool in mammals, and the genes are present in tandem copies. Comparison of KRTAP1 gene repeats from species across the mammalian phylogeny shows strongly contrasting evolutionary patterns between the coding regions, which have a concerted evolution pattern, and the flanking regions, which have a normal, radiating pattern of evolution. This dichotomy in evolutionary pattern transitions abruptly at the start and stop codons, and we show it is not the result of purifying selection acting to maintain species-specific protein sequences, nor of codon adaptation or reverse transcription of KRTAP1-n mRNA. Instead, the results are consistent with short-tract gene conversion events coupled with selection for these events in the coding region driving the contrasting evolutionary patterns found in the KRTAP1 repeats. Our work shows the power that repeat recombination has to complement selection and finely tune the sequences of repetitive genes. Interplay between selection and recombination may be a more common mechanism than currently appreciated for achieving specific adaptive outcomes in the many eukaryotic multi-gene families, and our work argues for greater emphasis on exploring the sequence structures of these families.

scholarly journals Parent–offspring similarity in the timing of developmental events: an origin of heterochrony?

2013 ◽  
Vol 280 (1769) ◽  
pp. 20131479 ◽  
Author(s):  
Oliver Tills ◽  
Simon D. Rundle ◽  
John I. Spicer
Keyword(s):  
High Resolution ◽  
Embryonic Development ◽  
Intraspecific Variation ◽  
Genetic Basis ◽  
Raw Material ◽  
Pond Snail ◽  
Developmental Event ◽  
Event Timing ◽  
Radix Balthica ◽  
Temporal And Spatial

Understanding the link between ontogeny (development) and phylogeny (evolution) remains a key aim of biology. Heterochrony, the altered timing of developmental events between ancestors and descendants, could be such a link although the processes responsible for producing heterochrony, widely viewed as an interspecific phenomenon, are still unclear. However, intraspecific variation in developmental event timing, if heritable, could provide the raw material from which heterochronies originate. To date, however, heritable developmental event timing has not been demonstrated, although recent work did suggest a genetic basis for intraspecific differences in event timing in the embryonic development of the pond snail, Radix balthica . Consequently, here we used high-resolution (temporal and spatial) imaging of the entire embryonic development of R. balthica to perform a parent–offspring comparison of the timing of twelve, physiological and morphological developmental events. Between-parent differences in the timing of all events were good predictors of such timing differences between their offspring, and heritability was demonstrated for two of these events (foot attachment and crawling). Such heritable intraspecific variation in developmental event timing could be the raw material for speciation events, providing a fundamental link between ontogeny and phylogeny, via heterochrony.

scholarly journals Temperature sensitivity of Notch signaling underlies species-specific developmental plasticity and robustness in amniote brains

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Tadashi Nomura ◽  
Kohjiro Nagao ◽  
Ryo Shirai ◽  
Hitoshi Gotoh ◽  
Masato Umeda ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Temperature Sensitivity ◽  
Developmental Plasticity ◽  
Molecular Mechanisms ◽  
Thermal Sensitivity ◽  
Neural Progenitors ◽  
Temperature Dependent ◽  
Ambient Temperatures ◽  
Species Specific ◽  
Notch Activation

AbstractAmbient temperature significantly affects developmental timing in animals. The temperature sensitivity of embryogenesis is generally believed to be a consequence of the thermal dependency of cellular metabolism. However, the adaptive molecular mechanisms that respond to variations in temperature remain unclear. Here, we report species-specific thermal sensitivity of Notch signaling in the developing amniote brain. Transient hypothermic conditions increase canonical Notch activity and reduce neurogenesis in chick neural progenitors. Increased biosynthesis of phosphatidylethanolamine, a major glycerophospholipid components of the plasma membrane, mediates hypothermia-induced Notch activation. Furthermore, the species-specific thermal dependency of Notch signaling is associated with developmental robustness to altered Notch signaling. Our results reveal unique regulatory mechanisms for temperature-dependent neurogenic potentials that underlie developmental and evolutionary adaptations to a range of ambient temperatures in amniotes.

scholarly journals The partitioning of symbionts effects on host resource acquisition and developmental plasticity

2020 ◽  
Author(s):  
Robin Guilhot ◽  
Anne Xuéreb ◽  
Simon Fellous
Keyword(s):  
Larval Development ◽  
Developmental Plasticity ◽  
Resource Acquisition ◽  
Adult Size ◽  
Specific Effects ◽  
Symbiosis Evolution ◽  
Species Specific ◽  
Shed Light ◽  
Host Resource ◽  
New Framework

AbstractMany symbionts provide nutrients to their host and/or affect its phenotypic plasticity. Such symbiont effects on host resource acquisition and allocation are often simultaneous and difficult to disentangle. Here we partitioned symbiont effects on host resource acquisition and allocation using a new framework based on the analysis of a well-established trade-off between host fitness components. This framework was used to analyze the effect of symbiotic yeast on the larval development of Drosophila larvae in field-realistic conditions. The screening of eighteen yeast fresh isolates showed they had similar effects on the resource acquisition in Drosophila melanogaster, D. simulans and D. suzukii but species-specific effects on resource allocation between either larval development speed or adult size. These differences shed light on the ecology of Drosophila flies and illustrate why distinguishing between these qualitatively different effects of microorganisms on hosts is essential to understand and predict symbiosis evolution.

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