Micro- and macroevolutionary change of colony-level traits in bryozoans

The evolution of trait variation among populations of animals is difficult to study due to the many overlapping genetic and environmental influences that control phenotypic expression. In a group of animals, bryozoans, it is possible to isolate genetic contributions to phenotypic variation, due to the modular nature of bryozoan colonies. Each bryozoan colony represents a snapshot of the phenotypes that correspond to a single genotype, which can be summarized as a phenotypic distribution. We test whether these phenotypic distributions are heritable across generations of colonies in two sister species of the bryozoan Stylopoma, grown and bred in a common garden breeding experiment. We find that components of phenotypic distributions, specifically median trait values of colony members, are heritable between generations of colonies. Furthermore, this heredity has macroevolutionary importance because it correlates with the morphological distance between these two species. Because parts of phenotypic distributions are heritable, and this heritability corresponds to evolutionary divergence between species, we infer that these distributions have the potential to evolve. The evolutionary potential of these phenotypic distributions may underpin the emergence of colony-level traits, like division of labor in colonies.

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How colonial animals evolve

Science Advances ◽

10.1126/sciadv.aaw9530 ◽

2020 ◽

Vol 6 (2) ◽

pp. eaaw9530 ◽

Cited By ~ 2

Author(s):

Carl Simpson ◽

Amalia Herrera-Cubilla ◽

Jeremy B. C. Jackson

Keyword(s):

Common Garden ◽

Evolutionary Change ◽

Common Garden Experiment ◽

Evolutionary Potential ◽

Reef Corals ◽

Evolutionary Conflict ◽

Individual Traits ◽

Colony Level

The evolution of modular colonial animals such as reef corals and bryozoans is enigmatic because of the ability for modules to proliferate asexually as whole colonies reproduce sexually. This reproductive duality creates an evolutionary tension between modules and colonies because selection operates at both levels. To understand how this evolutionary conflict is resolved, we compared the evolutionary potential of module- and colony-level traits in two species of the bryozoan Stylopoma, grown and bred in a common garden experiment. We find quantitatively distinct differences in the evolutionary potential of modular and colony traits. Contrary to solitary organisms, individual traits are not heritable from mother to daughter modules, but colony traits are strongly heritable from parent to offspring colonies. Colony-level evolution therefore dominates because no evolutionary change can accumulate among its modules.

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Genetic specificity of a plant–insect food web: Implications for linking genetic variation to network complexity

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1513633113 ◽

2016 ◽

Vol 113 (8) ◽

pp. 2128-2133 ◽

Cited By ~ 37

Author(s):

Matthew A. Barbour ◽

Miguel A. Fortuna ◽

Jordi Bascompte ◽

Joshua R. Nicholson ◽

Riitta Julkunen-Tiitto ◽

...

Keyword(s):

Genetic Variation ◽

Food Web ◽

Host Plant ◽

Trophic Interactions ◽

Common Garden ◽

Ecological Networks ◽

Experimental Population ◽

Trait Variation ◽

Intraspecific Genetic Variation ◽

Food Web Complexity

Theory predicts that intraspecific genetic variation can increase the complexity of an ecological network. To date, however, we are lacking empirical knowledge of the extent to which genetic variation determines the assembly of ecological networks, as well as how the gain or loss of genetic variation will affect network structure. To address this knowledge gap, we used a common garden experiment to quantify the extent to which heritable trait variation in a host plant determines the assembly of its associated insect food web (network of trophic interactions). We then used a resampling procedure to simulate the additive effects of genetic variation on overall food-web complexity. We found that trait variation among host-plant genotypes was associated with resistance to insect herbivores, which indirectly affected interactions between herbivores and their insect parasitoids. Direct and indirect genetic effects resulted in distinct compositions of trophic interactions associated with each host-plant genotype. Moreover, our simulations suggest that food-web complexity would increase by 20% over the range of genetic variation in the experimental population of host plants. Taken together, our results indicate that intraspecific genetic variation can play a key role in structuring ecological networks, which may in turn affect network persistence.

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AnEimeriavaccine candidate appears to be lactate dehydrogenase; characterization and comparative analysis

Parasitology ◽

10.1017/s0031182004005104 ◽

2004 ◽

Vol 128 (6) ◽

pp. 603-616 ◽

Cited By ~ 17

Author(s):

D. SCHAAP ◽

G. ARTS ◽

J. KROEZE ◽

R. NIESSEN ◽

S. V. ROOSMALEN-VOS ◽

...

Keyword(s):

Amino Acid ◽

Lactate Dehydrogenase ◽

3D Model ◽

Amino Acid Sequences ◽

Evolutionary Divergence ◽

Model Structure ◽

Partial Protection ◽

Primary Amino ◽

The Many ◽

Intracellular Stage

AnEimeria acervulinaprotein fraction was identified which conferred partial protection against anE. acervulinachallenge infection. From this fraction a 37 kDa protein was purified and its corresponding cDNA was cloned and shown to encode a lactate dehydrogenase (LDH). Full length cDNAs encoding LDH from two related species,E. tenellaandE. maxima, were also cloned. The homology between the primary amino acid sequences of these threeEimeriaLDH enzymes was rather low (66–80%), demonstrating an evolutionary divergence. ThePlasmodiumLDH crystal structure was used to generate a 3D-model structure ofE. tenellaLDH, which demonstrated that the many variations in the primary amino acid sequences (P. falciparumLDH andE. tenellaLDH show only 47% identity) had not resulted in altered 3D-structures. Only a single LDH gene was identified inEimeria, which was active as a homotetramer. The protein was present at similar levels throughout different parasitic stages (oocysts, sporozoites, schizonts and merozoites), but its corresponding RNA was only observed in the schizont stage, suggesting that its synthesis is restricted to the intracellular stage.

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Water warming increases aggression in a tropical fish

Scientific Reports ◽

10.1038/s41598-020-76780-1 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Zi Xun Kua ◽

Ian M. Hamilton ◽

Allison L. McLaughlin ◽

Reed M. Brodnik ◽

S. Conor Keitzer ◽

...

Keyword(s):

Lake Tanganyika ◽

Phenotypic Expression ◽

Tropical Fish ◽

Eastern Africa ◽

Negative Effects ◽

Stable Conditions ◽

Future Warming ◽

The Many ◽

The Tropics ◽

Average Individual

AbstractOur understanding of how projected climatic warming will influence the world’s biota remains largely speculative, owing to the many ways in which it can directly and indirectly affect individual phenotypes. Its impact is expected to be especially severe in the tropics, where organisms have evolved in more physically stable conditions relative to temperate ecosystems. Lake Tanganyika (eastern Africa) is one ecosystem experiencing rapid warming, yet our understanding of how its diverse assemblage of endemic species will respond is incomplete. Herein, we conducted a laboratory experiment to assess how anticipated future warming would affect the mirror-elicited aggressive behaviour of Julidochromis ornatus, a common endemic cichlid in Lake Tanganyika. Given linkages that have been established between temperature and individual behaviour in fish and other animals, we hypothesized that water warming would heighten average individual aggression. Our findings support this hypothesis, suggesting the potential for water warming to mediate behavioural phenotypic expression through negative effects associated with individual health (body condition). We ultimately discuss the implications of our findings for efforts aimed at understanding how continued climate warming will affect the ecology of Lake Tanganyika fishes and other tropical ectotherms.

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The many nuanced evolutionary consequences of duplicated genes

10.1101/366971 ◽

2018 ◽

Author(s):

Ashley I. Teufel ◽

Mackenzie M. Johnson ◽

Jon M. Laurent ◽

Aashiq H. Kachroo ◽

Edward M. Marcotte ◽

...

Keyword(s):

Functional Divergence ◽

Protein Structures ◽

Evolutionary Divergence ◽

Functional Changes ◽

Binding Interface ◽

Evolutionary Trajectories ◽

Conventional Models ◽

The Many ◽

Evolutionary Consequences ◽

Dosage Imbalance

AbstractGene duplication is seen as a major source of structural and functional divergence in genome evolution. Under the conventional models of sub- or neofunctionalizaton, functional changes arise in one of the duplicates after duplication. However, we suggest here that the presence of a duplicated gene can result in functional changes to its interacting partners. We explore this hypothesis by in-silico evolution of a heterodimer when one member of the interacting pair is duplicated. We examine how a range of selection pressures and protein structures leads to differential patterns of evolutionary divergence. We find that a surprising number of distinct evolutionary trajectories can be observed even in a simple three member system. Further, we observe that selection to correct dosage imbalance can affect the evolution of the initial function in several unexpected ways. For example, if a duplicate is under selective pressure to avoid binding its original binding partner, this can lead to changes in the binding interface of a non-duplicated interacting partner to exclude the duplicate. Hence, independent of the fate of the duplicate, its presence can impact how the original function operates. Additionally, we introduce a conceptual framework to describe how interacting partners cope with dosage imbalance after duplication. Contextualizing our results within this framework reveals that the evolutionary path taken by a duplicate’s interacting partners is highly stochastic in nature. Consequently, the fate of duplicate genes may not only be controlled by their own ability to accumulate mutations but also by how interacting partners cope with them.

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Transposon-mediated insertional mutagenesis unmasks recessive insecticide resistance in the aphid Myzus persicae

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2100559118 ◽

2021 ◽

Vol 118 (23) ◽

pp. e2100559118

Author(s):

Michela Panini ◽

Olga Chiesa ◽

Bartlomiej J. Troczka ◽

Mark Mallott ◽

Gian Carlo Manicardi ◽

...

Keyword(s):

Insecticide Resistance ◽

Myzus Persicae ◽

Genetic Variants ◽

Insertional Mutagenesis ◽

Phenotypic Expression ◽

Monoallelic Expression ◽

Resistance Mutations ◽

Evolutionary Potential ◽

Resistant Allele ◽

Susceptible Allele

The evolution of resistance to insecticides threatens the sustainable control of many of the world’s most damaging insect crop pests and disease vectors. To effectively combat resistance, it is important to understand its underlying genetic architecture, including the type and number of genetic variants affecting resistance and their interactions with each other and the environment. While significant progress has been made in characterizing the individual genes or mutations leading to resistance, our understanding of how genetic variants interact to influence its phenotypic expression remains poor. Here, we uncover a mechanism of insecticide resistance resulting from transposon-mediated insertional mutagenesis of a genetically dominant but insecticide-susceptible allele that enables the adaptive potential of a previously unavailable recessive resistance allele to be unlocked. Specifically, we identify clones of the aphid pest Myzus persicae that carry a resistant allele of the essential voltage-gated sodium channel (VGSC) gene with the recessive M918T and L1014F resistance mutations, in combination with an allele lacking these mutations but carrying a Mutator-like element transposon insertion that disrupts the coding sequence of the VGSC. This results in the down-regulation of the dominant susceptible allele and monoallelic expression of the recessive resistant allele, rendering the clones resistant to the insecticide bifenthrin. These findings are a powerful example of how transposable elements can provide a source of evolutionary potential that can be revealed by environmental and genetic perturbation, with applied implications for the control of highly damaging insect pests.

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Heritability estimation via molecular pedigree reconstruction in a wild fish population reveals substantial evolutionary potential for sea age at maturity, but not size within age classes

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2018-0123 ◽

2019 ◽

Vol 76 (5) ◽

pp. 790-805 ◽

Cited By ~ 3

Author(s):

Thomas E. Reed ◽

Paulo Prodöhl ◽

Caroline Bradley ◽

John Gilbey ◽

Philip McGinnity ◽

...

Keyword(s):

Body Size ◽

Fish Population ◽

Wild Fish ◽

Phenotypic Traits ◽

Evolutionary Potential ◽

Heritable Variation ◽

Heritability Estimation ◽

Scottish Population ◽

Rapid Changes ◽

Genetic Contributions

While evolutionary responses require heritable variation, estimates of heritability (h2) from wild fish populations remain rare. A 20-year molecular pedigree for a wild Scottish population of Atlantic salmon (Salmo salar) was used to investigate genetic contributions to (co)variation in two important, correlated, phenotypic traits: “sea age” (number of winters spent at sea prior to spawning) and size-at-maturity (body length just prior to spawning). Sea age was strongly heritable (h2 = 0.51) and size exhibited moderate heritability (h2 = 0.27). A very strong genetic correlation (rG = 0.96) between these traits implied the same functional loci must underpin variation in each. Indeed, body size within sea ages had much lower heritability that did not differ significantly from zero. Thus, within wild S. salar populations, temporal changes in sea age composition could reflect evolutionary responses, whereas rapid changes of body size within sea ages are more likely due to phenotypic plasticity. These inheritance patterns will influence the scope of evolutionary responses to factors such as harvest or climate change and, hence, have management implications for salmonid populations comprising a mix of sea ages.

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Thermal physiology and thermoregulatory behaviour exhibit low heritability despite genetic divergence between lizard populations

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2018.0697 ◽

2018 ◽

Vol 285 (1878) ◽

pp. 20180697 ◽

Cited By ~ 20

Author(s):

Michael L. Logan ◽

John David Curlis ◽

Anthony L. Gilbert ◽

Donald B. Miles ◽

Albert K. Chung ◽

...

Keyword(s):

Thermal Performance ◽

Genetic Divergence ◽

Common Garden ◽

Response To Selection ◽

Thermal Physiology ◽

Evolutionary Potential ◽

Thermal Environments ◽

Performance Curves ◽

Brown Anole ◽

Thermoregulatory Behaviour

Ectothermic species are particularly sensitive to changes in temperature and may adapt to changes in thermal environments through evolutionary shifts in thermal physiology or thermoregulatory behaviour. Nevertheless, the heritability of thermal traits, which sets a limit on evolutionary potential, remains largely unexplored. In this study, we captured brown anole lizards ( Anolis sagrei ) from two populations that occur in contrasting thermal environments. We raised offspring from these populations in a laboratory common garden and compared the shape of their thermal performance curves to test for genetic divergence in thermal physiology. Thermal performance curves differed between populations in a common garden in ways partially consistent with divergent patterns of natural selection experienced by the source populations, implying that they had evolved in response to selection. Next, we estimated the heritability of thermal performance curves and of several traits related to thermoregulatory behaviour. We did not detect significant heritability in most components of the thermal performance curve or in several aspects of thermoregulatory behaviour, suggesting that contemporary selection is unlikely to result in rapid evolution. Our results indicate that the response to selection may be slow in the brown anole and that evolutionary change is unlikely to keep pace with current rates of environmental change.

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The Many Nuanced Evolutionary Consequences of Duplicated Genes

Molecular Biology and Evolution ◽

10.1093/molbev/msy210 ◽

2018 ◽

Vol 36 (2) ◽

pp. 304-314 ◽

Cited By ~ 10

Author(s):

Ashley I Teufel ◽

Mackenzie M Johnson ◽

Jon M Laurent ◽

Aashiq H Kachroo ◽

Edward M Marcotte ◽

...

Keyword(s):

Functional Divergence ◽

Protein Structures ◽

Evolutionary Divergence ◽

Functional Changes ◽

Binding Interface ◽

Evolutionary Trajectories ◽

Conventional Models ◽

The Many ◽

Evolutionary Consequences ◽

Dosage Imbalance

Abstract Gene duplication is seen as a major source of structural and functional divergence in genome evolution. Under the conventional models of sub or neofunctionalization, functional changes arise in one of the duplicates after duplication. However, we suggest here that the presence of a duplicated gene can result in functional changes to its interacting partners. We explore this hypothesis by in silico evolution of a heterodimer when one member of the interacting pair is duplicated. We examine how a range of selection pressures and protein structures leads to differential patterns of evolutionary divergence. We find that a surprising number of distinct evolutionary trajectories can be observed even in a simple three member system. Further, we observe that selection to correct dosage imbalance can affect the evolution of the initial function in several unexpected ways. For example, if a duplicate is under selective pressure to avoid binding its original binding partner, this can lead to changes in the binding interface of a nonduplicated interacting partner to exclude the duplicate. Hence, independent of the fate of the duplicate, its presence can impact how the original function operates. Additionally, we introduce a conceptual framework to describe how interacting partners cope with dosage imbalance after duplication. Contextualizing our results within this framework reveals that the evolutionary path taken by a duplicate’s interacting partners is highly stochastic in nature. Consequently, the fate of duplicate genes may not only be controlled by their own ability to accumulate mutations but also by how interacting partners cope with them.

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Insights into speciation and species delimitation of closely related eucalypts using an interdisciplinary approach

Australian Systematic Botany ◽

10.1071/sb18042 ◽

2020 ◽

Vol 33 (1) ◽

pp. 110

Author(s):

Susan Rutherford

Keyword(s):

Species Delimitation ◽

Evolutionary Biology ◽

Population Genomics ◽

Interdisciplinary Approach ◽

Common Garden ◽

Green Ash ◽

Central Process ◽

Seedling Traits ◽

The Many ◽

Life On Earth

Speciation is a central process in evolutionary biology and is responsible for the diversity of life on Earth. Although there has been much progress in evolutionary research over the past 150 years, understanding the many facets of speciation remains a challenge. In this synthesis, I focus on the use of an interdisciplinary approach to examine speciation and species delimitation in a group of closely related eucalypts called the green ashes (Eucalyptus subgenus Eucalyptus section Eucalyptus). The green ashes comprise tall trees on fertile soils (e.g. the tallest angiosperm in the world, E. regnans), as well as medium trees and mallees on low-nutrient soils. Previous phylogenetic and population-genetics analyses based on genome-wide scans showed that species boundaries in the green ashes are not always consistent with classifications based on morphology and there was evidence of gene flow across lineages. Genomic analyses also suggested that the green ashes were at varying stages of speciation, with some species being highly genetically differentiated, whereas others were at earlier stages on the speciation continuum. A previous common garden study showed that inter-specific differences in seedling traits were significant, with traits such as leaf width being highly plastic across resource treatments for most species. Overall, this synthesis demonstrated that an interdisciplinary approach incorporating phylogenomics, population genomics and a common garden experiment can provide insights into speciation and species delimitation in the green ash eucalypts. Such an approach may be useful in understanding the evolutionary history of other closely related species in Eucalyptus, as well as other groups of organisms.

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