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Stichting International Foundation for Animal Genetics Missense variants are associated with various phenotypic traits and disorders in dogs. The canine P2RX7 gene, coding the ATP-gated P2X7 receptor ion channel, contains four known missense variants. The current study aimed to examine the presence of these variants in a random sample of pedigree and mixed-pedigree dogs. Exons 3, 8, 11 and 13 of the P2RX7 gene, encoding these four respective variants, in 65 dogs were assessed by Sanger sequencing and combined with existing sequencing data from another 69 dogs. The distribution of these variants was then evaluated in all 134 dogs combined and separately within individual breeds including 35 different pure breeds. The rs23314713 (p.Phe103Leu) and rs23315462 (p.Pro452Ser) variants were present in 47 and 40% of all dogs studied respectively, with the rs23314713 variant associated with brachycephalic breeds. Among pedigree dogs, the rs23314713 and rs23315462 variants were associated with brachycephalic and non-brachycephalic breeds respectively. The rs851148233 (p.Arg270Cys) and rs850760787 (p.Arg365Gln) variants were present only in dogs of Cocker Spaniel and Labrador Retriever pedigrees respectively. No other missense variants were found in exons 3, 8, 11 and 13 of the P2RX7 gene within the dogs. In conclusion, the rs23314713 and rs23315462 missense variants of the P2RX7 gene are present in a large proportion of dogs, with the rs23314713 variant associated with a number of brachycephalic breeds. However, the association of this variant with dogs of bulldog ancestry, not brachycephaly per se, cannot be excluded.

Biogeographic patterns of globally widespread species are expected to reflect regional structure, as well as connectivity caused by occasional long-distance dispersal. We assessed the level and drivers of population structure, connectivity, and timescales of population isolation in one of the most widespread and ruderal plants in the world — the common moss Ceratodon purpureus. We applied phylogenetic, population genetic, and molecular dating analyses to a global (n = 147) sampling data set, using three chloroplast loci and one nuclear locus. The plastid data revealed several distinct and geographically structured lineages, with connectivity patterns associated with worldwide, latitudinal “bands.” These imply that connectivity is strongly influenced by global atmospheric circulation patterns, with dispersal and establishment beyond these latitudinal bands less common. Biogeographic patterns were less clear within the nuclear marker, with gene duplication likely hindering the detection of these. Divergence time analyses indicated that the current matrilineal population structure in C. purpureus has developed over the past six million years, with lineages diverging during the late Miocene, Pliocene, and Quaternary. Several colonization events in the Antarctic were apparent, as well as one old and distinct Antarctic clade, possibly isolated on the continent since the Pliocene. As C. purpureus is considered a model organism, the matrilineal biogeographic structure identified here provides a useful framework for future genetic and developmental studies on bryophytes. Our general findings may also be relevant to understanding global environmental influences on the biogeography of other organisms with microscopic propagules (e.g., spores) dispersed by wind.

© 2020 The British Pharmacological Society Background and Purpose: P2X4 receptors are emerging therapeutic targets for treating chronic pain and cardiovascular disease. Dogs are well-recognised natural models of human disease, but information regarding P2X4 receptors in dogs is lacking. To aid the development and validation of P2X4 receptor ligands, we have characterised and compared canine and human P2X4 receptors. Experimental Approach: Genomic DNA was extracted from whole blood samples from 101 randomly selected dogs and sequenced across the P2RX4 gene to identify potential missense variants. Recombinant canine and human P2X4 receptors tagged with Emerald GFP were expressed in 1321N1 and HEK293 cells and analysed by immunoblotting and confocal microscopy. In these cells, receptor pharmacology was characterised using nucleotide-induced Fura-2 AM measurements of intracellular Ca2+ and known P2X4 receptor antagonists. P2X4 receptor-mediated inward currents in HEK293 cells were assessed by automated patch clamp. Key Results: No P2RX4 missense variants were identified in any canine samples. Canine and human P2X4 receptors were localised primarily to lysosomal compartments. ATP was the primary agonist of canine P2X4 receptors with near identical efficacy and potency at human receptors. 2′(3′)-O-(4-benzoylbenzoyl)-ATP, but not ADP, was a partial agonist with reduced potency for canine P2X4 receptors compared to the human orthologues. Five antagonists inhibited canine P2X4 receptors, with 1-(2,6-dibromo-4-isopropyl-phenyl)-3-(3-pyridyl)urea displaying reduced sensitivity and potency at canine P2X4 receptors. Conclusion and Implications: P2X4 receptors are highly conserved across dog pedigrees and display expression patterns and pharmacological profiles similar to human receptors, supporting validation and use of therapeutic agents for P2X4 receptor-related disease onset and management in dogs and humans.

What drives the evolution of sociality in animals? Many robust studies in terrestrial organisms have pointed toward various kinship-based, ecological and life-history traits or phylogenetic constraint which have played a role in the evolution of sociality. These traits are not mutually exclusive and the exact combination of traits is likely taxon-specific. Phylogenetic comparative analyses have been instrumental in identifying social lineages and comparing various traits with non-social lineages to give broad evolutionary perspectives on the development of sociality. Few studies have attempted this approach in marine vertebrate systems. Social marine fishes are particularly interesting because many have a pelagic larval phase and non-conventional life-history strategies (e.g. bi-directional sex-change) not often observed in terrestrial animals. Such strategies provide novel insights into terrestrially-derived theories of social evolution. Here, we assess the strength of the phylogenetic signal of sociality in the Gobiodon genus with Pagel's lambda and Blomberg's K parameters. We found some evidence of a phylogenetic signal of sociality, but factors other than phylogenetic constraint also have a strong influence on the extant social state of each species. We then use phylogenetic generalized least squares analyses to examine several ecological and life-history traits that may have influenced the evolution of sociality in the genus. We found an interaction of habitat size and fish length was the strongest predictor of sociality. Sociality in larger species was more dependent on coral size than in smaller species, but smaller species were more social overall, regardless of coral size. Finally, we comment on findings regarding the validity of the species G. spilophthalmus which arose during the course of our research. These findings in a group of marine fishes add a unique perspective on the evolution of sociality to the excellent terrestrial work conducted in this fiel

Social organization is a key factor influencing a species' foraging and reproduction, which may ultimately affect their survival and ability to recover from catastrophic disturbance. Severe weather events such as cyclones can have devastating impacts to the physical structure of coral reefs and on the abundance and distribution of its faunal communities. Despite the importance of social organization to a species' survival, relatively little is known about how major disturbances such as tropical cyclones may affect social structures or how different social strategies affect a species' ability to cope with disturbance. We sampled group sizes and coral sizes of group-forming and pair-forming species of the Gobiid genus Gobiodon at Lizard Island, Great Barrier Reef, Australia, before and after two successive category 4 tropical cyclones. Group sizes of group-forming species decreased after each cyclone, but showed signs of recovery four months after the first cyclone. A similar increase in group sizes was not evident in group-forming species after the second cyclone. There was no change in mean pair-forming group size after either cyclone. Coral sizes inhabited by both group- and pair-forming species decreased throughout the study, meaning that group-forming species were forced to occupy smaller corals on average than before cyclone activity. This may reduce their capacity to maintain larger group sizes through multiple processes. We discuss these patterns in light of two non-exclusive hypotheses regarding the drivers of sociality in Gobiodon, suggesting that benefits of philopatry with regards to habitat quality may underpin the formation of social groups in this genus.

Why do we observe so many examples in nature in which individuals routinely delay or completely forgo their own reproductive opportunities in order to join and remain within a group? Cooperative breeding theory provides a rich framework with which to study the factors that may influence the costs and benefits of remaining philopatric as a non-breeder. This is often viewed as an initial step in the development of costly helping behavior provided by non-breeding subordinates. Despite many excellent empirical studies testing key concepts of the theory, there is still debate regarding the relative importance of various evolutionary forces, suggesting that there may not be a general explanation but rather a dynamic and taxonomically varied combination of factors influencing the evolution and maintenance of sociality. Here, we explore two potential improvements in t he study of sociality that could aid in the progress of this field. The first addresses the fact that empirical studies of social evolution are typically conducted using either comparative, observational or manipulative methodologies. Instead, we suggest a holistic approach, whereby observational and experimental studies are designed with the explicit view of advancing comparative analyses of sociality for the taxon, and in tandem, where comparative work informs targeted research effort on specific (usually understudied) species within the lineage. A second improvement relates to the broadening of tests of cooperative breeding theory to include taxa where subordinates do not necessarily provide active cooperation within the group. The original bias toward "helpful subordinates" arose from a focus on terrestrial taxa. However, recent consideration of other taxa, especially marine taxa, is slowly revealing that the theory can and should encompass a continuum of cooperative social systems, including those where subordinates do not actively help. This review summarizes the major hypotheses of cooperative breeding

Higher-level hymenopteran relationships remain unresolved in both morphological and molecular analyses. In this study, we present the most comprehensive analyses of hymenopteran relationships based on 48 mitochondrial (mt) genomes. One complete and two nearly complete mt genomes representing three hymenopteran superfamilies were newly sequenced. We assessed the influence of inclusion/exclusion of 3rd codon positions, alignment approaches, partition schemes and phylogenetic approaches on topology and nodal support within the Hymenoptera. The results showed that the topologies were sensitive to the variation of dataset and analytical approach. However, some robust and highly supported relationships were recovered: the Ichneumonomorpha was monophyletic; the Trigonalyoidea + Megalyroidea and the Diaprioidea + Chalcidoidea were consistently recovered; the Cynipoidea was generally recovered as the sister group to the Diaprioidea + Chalcidoidea. In addition, the monophyletic Aculeata and Proctotrupomorpha were recovered in some analyses. Several gene rearrangements were detected in each of the three newly sequenced mt genomes. Specifically, the Ibalia leucospoides mt genome harbors a large inversion of a gene block from trnE to trnS2. Inverted, duplicated A + T rich regions were detected in the Ibalia leucospoides mt genome, which probably played an important role during the formation of the large gene block inversion via recombination.

Members of the Calliphoridae (blowflies) are significant for medical and veterinary management, due to the ability of some species to consume living flesh as larvae, and for forensic investigations due to the ability of others to develop in corpses. Due to the difficulty of accurately identifying larval blowflies to species there is a need for DNA-based diagnostics for this family, however the widely used DNA-barcoding marker, cox1, has been shown to fail for several groups within this family. Additionally, many phylogenetic relationships within the Calliphoridae are still unresolved, particularly deeper level relationships. Sequencing whole mt genomes has been demonstrated both as an effective method for identifying the most informative diagnostic markers and for resolving phylogenetic relationships. Twenty-seven complete, or nearly so, mt genomes were sequenced representing 13 species, seven genera and four calliphorid subfamilies and a member of the related family Tachinidae. PCR and sequencing primers developed for sequencing one calliphorid species could be reused to sequence related species within the same superfamily with success rates ranging from 61% to 100%, demonstrating the speed and efficiency with which an mt genome dataset can be assembled. Comparison of molecular divergences for each of the 13 protein-coding genes and 2 ribosomal RNA genes, at a range of taxonomic scales identified novel targets for developing as diagnostic markers which were 117-200% more variable than the markers which have been used previously in calliphorids. Phylogenetic analysis of whole mt genome sequences resulted in much stronger support for family and subfamily-level relationships. The Calliphoridae are polyphyletic, with the Polleninae more closely related to the Tachinidae, and the Sarcophagidae are the sister group of the remaining calliphorids. Within the Calliphoridae, there was strong support for the monophyly of the Chrysomyinae and Luciliinae and for the sister-grou

We assessed the rate of in vitro polymerase errors at polythymidine [poly(T)] tracts in the mitochondrial DNA (mtDNA) of a heteroderid nematode (Heterodera cajani). The mtDNA of these nematodes contain unusually high numbers of poly(T) tracts, and have previously been suggested to contain biological poly(T) length variation. However, using a cloned molecule, we observed that poly(T) variation was generated in vitro at regions containing more than six consecutive Ts. This artefactual error rate was estimated at 7.3 × 10−5 indels/poly(T) tract >6 Ts/cycle. This rate was then compared to the rate of poly(T) variation detected after the amplification of a biological sample, in order to estimate the ‘biological + artefactual’ rate of poly(T) variation. There was no significant difference between the artefactual and the artefactual + biological rates, suggesting that the majority of poly(T) variation in the biological sample was artefactual. We then examined the generation of poly(T) variation in a range of templates with tracts up to 16 Ts long, utilizing a range of Heteroderidae species. We observed that T deletions occurred five times more frequently than insertions, and a trend towards increasing error rates with increasing poly(T) tract length. These findings have significant implications for studies involving genomes with many homopolymer tracts.

We sequenced the entire coding region of the mitochondrial genome of Heterodera glycines. The sequence obtained comprised 14.9kb, with PCR evidence indicating that the entire genome comprised a single, circular molecule of approximately 21-22kb. The genome is the most T-rich nematode mitochondrial genome reported to date, with T representing over half of all nucleotides on the coding strand. The genome also contains the highest number of poly(T) tracts so far reported (to our knowledge), with 60 poly(T) tracts ¿ 12 Ts. All genes are transcribed from the same mitochondrial strand. The organization of the mitochondrial genome of H. glycines shows a number of similarities compared with Radopholus similis, but fewer similarities when compared with Meloidogyne javanica. Very few gene boundaries are shared with Globodera pallida or Globodera rostochiensis. Partial mitochondrial genome sequences were also obtained for Heterodera cardiolata (5.3kb) and Punctodera chalcoensis (6.8kb), and these had identical organizations compared with H. glycines. We found PCR evidence of a minicircular mitochondrial genome in P. chalcoensis, but at low levels and lacking a noncoding region. Such circularised genome fragments may be present at low levels in a range of nematodes, with multipartite mitochondrial genomes representing a shift to a condition in which these subgenomic circles predominate. C 2011 Published by NRC Research Press.

The utility of the forensically important Sarcophagidae (Diptera) for time since death estimates has been severely limited, as morphological identification is difficult and thermobiological histories are inadequately documented. A molecular identification method involving the sequencing of a 658-bp barcode fragment of the mitochondrial cytochrome oxidase subunit I (COI) gene from 85 specimens, representing 16 Australian species from varying populations, was evaluated. Nucleotide sequence divergences were calculated using the Kimura-two-parameter distance model and a neighbour-joining phylogenetic tree generated. All species were resolved as reciprocally monophyletic, except Sarcophaga dux. Intraspecific and interspecific variation ranged from 0.000% to 1.499% (SE = 0.044%) and 6.658% to 8.983% (SE = 0.653%), respectively. The COI barcode sequence was found to be suitable for the molecular identification of the studied Australian Sarcophagidae: 96.5% of the examined specimens were assigned to the correct species. Given that the sarcophagid fauna is poorly described, it is feasible that the few incorrectly assigned specimens represent cryptic species. The results of this research will be instrumental for implementation of the Australian Sarcophagidae in forensic entomology.

Chrysomya rufifacies is an ecologically and forensically important blowfly, widespread in Australasia, the Orient and the Americas. The recent molecular studies of Wallman et al.(2005) showed significant levels of nucleotide divergence between Australian populations of this species based on the cytochrome oxidase subunit two (COII) gene, suggesting that Ch. rufifacies is in fact two species. The present study used COII to verify the existence of these two putative species. A 642-bp fragment of COII was sequenced from 37 specimens sampled from 35 diverse Australian geographical locations and analysed using the Kimura-two-parameter distance model and Bayesian methods. Surprisingly, all Ch. rufifacies sequences demonstrated typical levels of mean intraspecific variation (mean = 0.042%, range = 0.000-0.315%, standard error = 0.003) and were resolved as a monophyletic group on the Bayesian tree. Reassessment of the original COII data of Wallman et al. (2005) showed that the high nucleotide divergence within Ch. rufifacies was attributed to two COII sequences actually derived from specimens of Lucilia porphyrina. Ultimately, this study does not support the hypothesis that Australian Ch. rufifacies comprises two cryptic species but instead confirms its existing status as a single taxon.

The correct identification of forensically important arthropods for post-mortem interval estimation is crucial, as the rate of larval development can vary substantially between species. The identification of forensically important blowflies of the genus Chrysomya (Diptera: Calliphoridae) may be hampered by their close morphological similarities, especially as immatures. The aim of this study was to establish whether genetically closely related blowfly species would share similar developmental profiles. This could permit the application of developmental data to a number of closely related species, including those for which thermodevelopmental studies are lacking. If Australian Chrysomya were found to share developmental profiles, identification of the blowfly specimen to a level beyond genus may not be necessary, or at least it may not be necessary to distinguish morphologically similar sister species. The three Chrysomya species studied were collected from the same geographical location (Cairns, Australia), reducing the effects of acclimation and population-level genetic variation. The experimental conditions in this study were virtually identical, which enabled direct comparisons to be made among the species. Blowfly larval lengths were obtained for 24-hourly intervals at constant temperatures of 25, 30, and 35 degrees C. The thermal preferences of newly-hatched feeding larvae were determined by their positions on a temperature gradient apparatus. This study established that all three species investigated differed significantly in their developmental profiles, despite the genetic closeness of the sister species Chrysomya megacephala (Fabricius) and Chrysomya saffranea (Bigot). Because of this, genetic distance was not considered to be a useful factor for predicting thermodevelopment profiles of closely related species within a genus, and highlights the necessity for correct species identification.