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opencc-zeroNov 2023View details →

Eggshell colour differences in a classic example of coevolved eggshell mimicry

Avian brood parasitism is a model system for understanding coevolutionary arms races, and the great reed warbler (Acrocephalus arundinaceus, hereafter 'warbler') and its parasite the common cuckoo (Cuculus canorus, hereafter 'cuckoo') are prime examples of this coevolutionary struggle. Here, warblers select for egg colour mimicry by rejecting poorly matched cuckoo eggs. Contrary to long-held assumptions, recent work showed that warblers tend to reject lighter and browner eggs but tended to accept darker and bluer eggs rather than basing rejection decisions solely on perceived colour differences (i.e., the degree of mimicry). This counter-intuitive, colour-biased rejection behaviour would select for bluer and darker cuckoo eggs, but would only be adaptive if cuckoos were consistently lighter and browner than warbler eggs. Therefore, we tested whether warbler eggs were consistently bluer and darker than the cuckoo eggs. To do so, we re-analysed eggshell reflectance spectra of warblers and the cuckoos that parasitized them in the Czech Republic. As expected, we found that warbler eggs were significantly bluer and darker than the cuckoo eggs at the population level. Thus, we demonstrate imperfect mimicry in a long-coevolved cuckoo host-race and provide insights for exploring the coevolutionary interactions among hosts and their brood parasites.

opencc-zeroDec 2023View details →

Selection for evasive mimicry imposed by an arthropod predator

It has long been hypothesized that a species that is relatively easy to catch by predators may face selection to resemble a species that is harder to catch. Several experiments using avian predators have since supported this "evasive mimicry" hypothesis. However, the sudden movement of artificial evasive prey in each of the above experiments may have startled the predators, generating an avoidance response unrelated to difficulty of capture. Additionally, in the above experiments, the catchability of prey was all or nothing, while in nature predators may occasionally catch evasive prey or fail to catch slower species, which might inhibit learning. Here, using mantids as predators, we conducted an experimental test of the evasive mimicry hypothesis that circumvents these limitations, using live painted calyptrate flies with modified evasive capabilities as prey. We found that mantids readily learned to avoid pursuing the more evasive prey types. Warning signals based on evasiveness and their associated mimicry may be widespread phenomena in nature. These findings not only further support its plausibility but demonstrate that even arthropod predators can select for it.

opencc-zeroFeb 2022View details →

Predator-based selection and the impact of edge sympatry on components of coral snake mimicry

Mimicry is a vivid example of how predator-driven selection can impact phenotypic diversity, which itself can be influenced by the presence (sympatry) or absence (allopatry) of a dangerous model. However, the impact of sympatry and allopatry on predation on mimicry systems at fine spatial scales (e.g., edge sympatry, allopatry) is not well understood. We used a clay model study in a montane tropical site in Honduras to test the impact of edge sympatry on 1) overall attack rates, 2) the fitness benefit of mimetic coloration, 3) predation on specific mimetic signal components, and 4) temporal variation in predator-based selection on mimicry components. Unlike previous research, we found that mimetic phenotypes received significantly more attacks than cryptic replicas in edge sympatry, suggesting that mimetic phenotypes might not confer a fitness benefit in areas of edge sympatry. Additionally, we documented temporal variation in predator-based selection, as the impacts of allopatry on predatory attacks varied among years. Our results imply that the effect of sympatry and allopatry on predator-based selection in mimicry systems may be more complex than previously thought for species-rich assemblies of coral snakes and their mimics in the montane tropics.

opencc-by-4.0Feb 2022View details →

Full Datasets for the "Molecular Mimicry Map of SARS-CoV-2" Web Application

A Full Dataset for the "Molecular Mimicry Map of SARS-CoV-2" Web Application This TAR archive file contains the minimally filtered list of potentially cross-reactive epitopes of SARS-CoV-2 and human proteins predicted by the CRESSP analysis pipeline (<a href="https://pypi.org/project/cressp/">https://pypi.org/project/cressp/</a>). Our web application, "Molecular Mimicry Map of SARS-CoV-2" (<a href="https://ahs2202.github.io/3M/">https://ahs2202.github.io/3M/</a>), only visualizes the high-scoring potential cross-reactive epitope pairs (40,000 epitope pairs maximum). However, for the researchers who want to access the complete list of potentially cross-reactive epitope pairs for further analysis, these full datasets can be used.

opencc-zeroApr 2022View details →

Uncovering the effects of Müllerian mimicry on the evolution of conspicuousness in colour patterns

Variation in the conspicuousness of colour patterns is observed within and among defended prey species. The evolution of conspicuous colour pattern in defended species can be strongly impaired because of increased detectability by predators. Nevertheless, such evolution of the colour pattern can be favoured if changes in conspicuousness result in Müllerian mimicry with other defended prey. Here, we develop a model describing the population dynamics of a conspicuous defended prey species, and we assess the invasion conditions of derived phenotypes that differ from the ancestral phenotype by their conspicuousness. Such change in conspicuousness may then modify their level of mimicry with the local community of defended species. Derived colour pattern displayed in this focal population can therefore be either exactly similar, partially resembling or completely dissimilar to the local mimicry ring displaying the ancestral colour pattern. We assume that predation risk depends (1) on the number of individuals sharing a given colour pattern within the population, (2) on the occurrence of co-mimetic defended species, and (3) on the availability of alternative edible prey. Using a combination of analytical derivations and numerical simulations, we show that colour patterns that are less conspicuous than the ancestral one are generally favoured within mimicry rings, unless reduced conspicuousness impairs mimicry. By contrast, when a mutation affecting the colour pattern leads to a shift toward a better protected mimicry ring, a more conspicuous colour pattern can be favoured. The selected aposematic pattern then depends on the local communities of defended and edible prey, as well as on the detectability, memorability and level of mimicry of the colour patterns.

opencc-by-4.0Jun 2022View details →

MOLECULAR MIMICRY BETWEEN TUMOR ASSOCIATED ANTIGENS AND MICROBIOTA-DERIVED EPITOPES.

Background: The gut microbiota profile is unique for each individual and are composed by different bacteria species according to individual birth-to-infant transitions. In the last years, the local and systemic effects of microbiota on cancer onset, progression and response to treatments, such as immunotherapies, have been extensively described. Here we offer a new perspective, proposing a role for the microbiota based on the molecular mimicry of tumor-associated antigens by microbiome-associated antigens. Methods: In the present study we looked for homology between published TAAs and non-self microbiota-derived epitopes. Blast search for sequence homology was combined with extensive bioinformatics analyses. Results: Several evidences for homology between TAAs and microbiota-derived antigens have been found. Strikingly, three cases of 100% homology between the paired sequences has been identified. The predicted average affinity to HLA molecules of microbiota-derived antigens is very high (<100nM). The structural conformation of the microbiota-derived epitopes is, in general, highly similar to the corresponding TAA. In some cases, it is identical and contact areas with both HLA and TCR chains are indistinguishable. Moreover, the spatial conformation of TCR-facing residues can be identical in paired TAA and microbiota-derived epitopes, with exactly the same values of planar as well as dihedral angles. Conclusions: The data reported in the present study show for the first time the high homology in the linear sequence as well as in structure and conformation between TAAs and peptides derived from microbiota species of the Firmicutes and the Bacteroidetes phyla, which together account for 90% of gut microbiota. Cross-reacting CD8+ T cell responses are very likely induced. Therefore, the anti-microbiota T cell memory may turn out to be an anti-cancer T cell memory, able to control the growth of cancer developed during the lifetime if the expressed TAA is similar to the microbiota epitope. This may ultimately represent a relevant selective advantage for cancer patients and may lead to a novel preventive anti-cancer vaccine strategy.

opencc-by-4.0May 2024View details →

Structural Homology of Epitope Pair Candidates for Molecular Mimicry Trigger of Type 1 Diabetes Mellitus

Background: Molecular mimicry, where foreign and self-peptides contain similar epitopes, can induce autoimmune responses. Identifying potential molecular mimics and studying their properties is key to understanding the onset of autoimmune diseases such as type 1 diabetes mellitus (T1DM). Previous work identified pairs of infectious epitopes (EINF) and T1DM epitopes (ET1D) that demonstrated sequence homology; however, structural homology was not considered. Correlating sequence homology with structural properties is important for streamlining translational investigation of potential molecular mimics. Therefore, the purpose of this work is to compare sequence homology with structural homology by calculating the structures and electrostatic potential surfaces of the epitope pairs identified in previous work from our laboratory.   Results:  For each epitope pair the root mean square deviation (RMSD) was calculated between their predicted structures and their electrostatic potentials were compared. Structures were predicted using the AlphaFold software program. Of the 52 epitope pairs considered here only 10 do not exhibit any matching (i.e. less than 3 residues overlap). When considering all residues the RMSD ranges from 0.33 Å to 11.66 Å with an average of 2.68 Å. Twenty-two pairs (42%) have RMSD of less than 1.5 Å and 30 (58%) less than 3 Å. Even some of the matching pairs show some electrostatic similarities that need to be considered. In general there is good agreement between the folding predicted for the isolated EINF and ET1D epitopes and the folding of the corresponding amino acid sequence in the parent antigen, but in some cases there are deviation that need to be considered, even when the RMDS is small.  Conclusions: Despite differences, most of the EINF/ET1D pairs selected by sequence homology show similar structural and electrostatic distributions, indicating that the EINF may bind to the same protein targets, the major histocompatibility complex molecules, for T1DM, leading to molecular mimicry onset of the disease. These findings suggest that searching for epitope pairs using sequence homology, a much less computationally demanding approach, leads to strong candidates for molecular mimicry that should be considered for further study. Still structure and full docking calculations will be necessary to advance the in-silico molecular mimicry predictions.  Here we presnt the following files: ·         Fasta files of all epitopes studied. ·         Alphafold calculated Structures of all epitopes. ·         Antigen structures. ·         Epitope pair structure comparison and their electrostatics.

opencc-by-4.0Dec 2017View details →

Fig. 2c. Tillomorphites otiliae n in Two new fossil species of Tillomorphites Vitali (Coleoptera: Cerambycidae) and remarks on the morphological evolution, mimicry, biogeography and phylogeny of the tribe Tillomorphini

Fig. 2c. Tillomorphites otiliae n. sp., habitus, Fig. 2 e. Tillomorphites otiliae n. sp., reconstruction. Paratype, colour reconstruction.

Fig. 11 in Five new species of the genus Polycatus Heller, 1912 (Coleoptera: Curculionidae: Polycatini) from the Mindanao Island (Philippines), and new examples of mimicry among weevil genera

Fig. 11: 1 – P. jaegeri sp. nov.; 2 – Pachyrhynchus zamboanganus Yoshitake, 2012; 3 – Metapocyrtus sp.; 4 – Calidiopsis speciosa Heller, 1913; 5 – P. mimicus sp. nov.; 6 – Pachyrhynchus tikoi Rukmane, 2016; 7 – P. bramanti sp. nov.; 8 – Pachyrhynchus subamabilis Yoshitake, 2012

Fig. 9. P in Five new species of the genus Polycatus Heller, 1912 (Coleoptera: Curculionidae: Polycatini) from the Mindanao Island (Philippines), and new examples of mimicry among weevil genera

Fig. 9. P. waoensis sp. nov. (BRAA). 1-5 male; 6-10 female; 11-13 aedegal body; 11 – sternite IX; 15 – sternite VIII; 16-17 spermatheca

Fig. 7. P in Five new species of the genus Polycatus Heller, 1912 (Coleoptera: Curculionidae: Polycatini) from the Mindanao Island (Philippines), and new examples of mimicry among weevil genera

Fig. 7. P. mimicus sp. nov. (DUBC). 1-5 male; 6-10 female; 11 – aedegal body in lateral view; 12 – aedegal body in dorsal view; 13 – sternite IX; 14 – aedegal body in ventral view; 15 – spermatheca; 16 – sternite VIII

Fig. 6 in Five new species of the genus Polycatus Heller, 1912 (Coleoptera: Curculionidae: Polycatini) from the Mindanao Island (Philippines), and new examples of mimicry among weevil genera

Fig. 6. TYPE of P. eupholoides (MTD). 1-5 male; 6 – aedegal body in ventral view; 7 – aedegal body in lateral view; 8 – aedegal body in dorsal view; 9 – sternite IX; 10 – drawing of P. eupholoides from it's original description

Fig. 1 in Five new species of the genus Polycatus Heller, 1912 (Coleoptera: Curculionidae: Polycatini) from the Mindanao Island (Philippines), and new examples of mimicry among weevil genera

Fig. 1. TYPE specimens of P. aurofasciatus (MTD). 1-5 male; 6-10 female; 11 – aedegal body in ventral view; 12- aedegal body in lateral view; 13 - aedegal body in dorsal view; 14 – sternite IX; 15 – sternite VIII; 16 – spermatheca

Fig. 5. P in Five new species of the genus Polycatus Heller, 1912 (Coleoptera: Curculionidae: Polycatini) from the Mindanao Island (Philippines), and new examples of mimicry among weevil genera

Fig. 5. P. vivesi sp. nov. (BRAA). 1-5 male; 6-10 female; 11- aedegal body in lateral view; 12 – aedegal body in dorsal view; 13 – sternite IX; 14 – aedegal body in ventral view; 15 – spermatheca; 16 – ovipositor; 17 – ventrite VIII

Fig. 2 in Five new species of the genus Polycatus Heller, 1912 (Coleoptera: Curculionidae: Polycatini) from the Mindanao Island (Philippines), and new examples of mimicry among weevil genera

Fig. 2. TYPE specimens of P. aurofasciatus dilatisignatus (MTD). 1-5 male; 6 – 10, 17 female; 11 – aedegal body in ventral view; 12- aedegal body in lateral view; 13 - aedegal body in dorsal view; 14 – sternite IX; 15 – sternite VIII; 16 – spermatheca

opencc-by-4.0Dec 2013View details →

Fig. 1 in Wasp mimicry among Palaeocene reduviid bug from Svalbard

Fig. 1. Representative assassin bugs of the subfamily Saicinae (Reduviidae), Recent (A–D) and fossil (E) specimens. A. Tagalis inornata Stål, 1860. B. Polytoxus wahlbergi Stål, 1855. C. Saica tibialis Stål, 1862. D. Uncoated ESEM on the wings of Tagalis sp. (det. Christiane Weirauch). E. Hymenopterites Heer, 1870, coll. No. Ar 46. Holotype specimen with orginal labeling from Alfred Erik Nordenskiöld (E1). Specimen photographed un− der normal light conditions (E2) and under alcohol (E3). F. Line drawing of forewing. Scale bars 1 mm.

opencc-zeroJul 2024View details →

Linked collectors and determiners for: Diversity of terrestrial arthropods exhibiting mimicry from Hazaribagh Plateau region.

Natural history specimen data linked to collectors and determiners held within, "Diversity of terrestrial arthropods exhibiting mimicry from Hazaribagh Plateau region". Claims or attributions were made on Bionomia by volunteer Scribes, <a href="https://bionomia.net/dataset/a79e719e-b5b7-4e4a-b963-af3a7ca408d9">https://bionomia.net/dataset/a79e719e-b5b7-4e4a-b963-af3a7ca408d9</a> using specimen data from the dataset aggregated by the Global Biodiversity Information Facility, <a href="https://gbif.org/dataset/a79e719e-b5b7-4e4a-b963-af3a7ca408d9">https://gbif.org/dataset/a79e719e-b5b7-4e4a-b963-af3a7ca408d9</a>. Formatted as a Frictionless Data package.