Panaxia Dominula Research Articles

The genome sequence of the Scarlet Tiger moth, Callimorpha dominula (Linnaeus, 1758).

We present a genome assembly from an individual male Callimorpha dominula (the Scarlet Tiger moth; Arthropoda; Insecta; Lepidoptera; Erebidae). The genome sequence is 658.1 megabases in span. Most of the assembly is scaffolded into 31 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 15.45 kilobases in length. Gene annotation of this assembly on Ensembl identified 20,234 protein coding genes.

Detecting and Quantifying Changing Selection Intensities from Time-Sampled Polymorphism Data.

During his well-known debate with Fisher regarding the phenotypic dataset of Panaxia dominula, Wright suggested fluctuating selection as a potential explanation for the observed change in allele frequencies. This model has since been invoked in a number of analyses, with the focus of discussion centering mainly on random or oscillatory fluctuations of selection intensities. Here, we present a novel method to consider nonrandom changes in selection intensities using Wright-Fisher approximate Bayesian (ABC)-based approaches, in order to detect and evaluate a change in selection strength from time-sampled data. This novel method jointly estimates the position of a change point as well as the strength of both corresponding selection coefficients (and dominance for diploid cases) from the allele trajectory. The simulation studies of this method reveal the combinations of parameter ranges and input values that optimize performance, thus indicating optimal experimental design strategies. We apply this approach to both the historical dataset of P. dominula in order to shed light on this historical debate, as well as to whole-genome time-serial data from influenza virus in order to identify sites with changing selection intensities in response to drug treatment.

Characterization of the complete mitochondrial genome of the Scarlet Tiger moth Callimorpha dominula (Insecta: Lepidoptera: Arctiidae)

The complete mitochondrial genome of the Scarlet Tiger moth Callimorpha dominula (Insecta: Lepidoptera: Arctiidae) has been reconstructed from the whole-genome Illumina sequencing data. This circular genome is 15 496 bp in size, and contains 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs), and one A + T-rich D-loop or control region. Most PCGs are initiated with the ATN codons, except for COX1 with the unusual CGA as its initiation codon. Four PCGs (COX1, COX2, ND3, and ND4) are terminated with incomplete codon T, ND4L uses TAG as its termination codon, while all the other eight PCGs employ the usual ATN codons. The nucleotide composition is highly asymmetric (40.1% A, 40.9% T, 7.6% G, and 11.4% C) with an overall A + T content of 81.0%. The phylogenetic analysis based on the neighbor-joining (NJ) method suggests that C. dominula is more phylogenetically related to its confamilial counterparts than to those from other families.

THE PROTECTED SPECIES OF LEPIDOPTERA IN THE LANDSCAPE RESERVE ‘ZVANETS’ (BELARUS)

The article contains the data on distribution, population, habitats and phenology of 16 species of lepidopteran insects (Insecta: Lepidoptera), inhabiting the landscape reserve “Zvanets” (Belarus, Brest region) and listed in the Red Book of the Republic of Belarus: Rhyparioides metelkana, Pericallia matronula, Callimorpha dominula, Arytrura musculus, Diachrysia zosimi, Chariaspilates formosaria, Scopula caricaria, Gagitodes sagittata, Lycaena dispar, Euphydryas aurinia, Eu. maturna, Melitaea phoebe, M. diamina, M. aurelia, M. britomartis, Coenonympha oedippus. The data conserning the habitat of Parnassius mnemosyne in the reserve are proposed to be considered unreliable. The study also provides the information on Polyommatus daphnis which had previously been a protected species.It was found that the preferred habitat for C. oedippus, Ch. formosaria, Rh. metelkana, A. musculus, D. zosimi is fen mire. It is possible that for Rh. metelkana and A. musculus the reserve “Zvanets” is the key area concerning their preservation in Europe. On the background of the ongoing extinction of these two species in Europe and in connection with burning of vegetation practised in “Zvanets”, the further study of Rh. metelkana and A. musculus, it is particularly relevant for the development and implementation of action plans for their saving.The widespread burning of vegetation on swamps affecting mineral islands (especially small ones) has negative impact on the Papilionoidea species. In larger forest areas which burn only fragmentary the Lepidoptera population is quickly restored in burnt places due to the resettlement from the areas not affected by fire. It requires the development of special protection measures for the Papilionoidea in the reserve area.With the legalization of target burnings in the reserve “Zvanets” the best way out of this situation is the differentiation of ways to fight the bush encroachment and overgrowth of reeds. It is expedient to split the reserve into a number of areas which will be subject to burning alternately in different years. To localize the fire they must be separated by pre-cutting of the low dividing strips. To prevent any further damage by fire to the mineral islands and margins of swamps and dams the unwanted vegetation along the margins of swamps, near the channels and on the borders of swamps with mineral islands should be removed by mowing and cutting out where possible.Key words: Lepidoptera, protection, Red Data Book, wildlife area, burning of vegetation, Belarus.

Ancient expansion of the hox cluster in lepidoptera generated four homeobox genes implicated in extra-embryonic tissue formation.

Gene duplications within the conserved Hox cluster are rare in animal evolution, but in Lepidoptera an array of divergent Hox-related genes (Shx genes) has been reported between pb and zen. Here, we use genome sequencing of five lepidopteran species (Polygonia c-album, Pararge aegeria, Callimorpha dominula, Cameraria ohridella, Hepialus sylvina) plus a caddisfly outgroup (Glyphotaelius pellucidus) to trace the evolution of the lepidopteran Shx genes. We demonstrate that Shx genes originated by tandem duplication of zen early in the evolution of large clade Ditrysia; Shx are not found in a caddisfly and a member of the basally diverging Hepialidae (swift moths). Four distinct Shx genes were generated early in ditrysian evolution, and were stably retained in all descendent Lepidoptera except the silkmoth which has additional duplications. Despite extensive sequence divergence, molecular modelling indicates that all four Shx genes have the potential to encode stable homeodomains. The four Shx genes have distinct spatiotemporal expression patterns in early development of the Speckled Wood butterfly (Pararge aegeria), with ShxC demarcating the future sites of extraembryonic tissue formation via strikingly localised maternal RNA in the oocyte. All four genes are also expressed in presumptive serosal cells, prior to the onset of zen expression. Lepidopteran Shx genes represent an unusual example of Hox cluster expansion and integration of novel genes into ancient developmental regulatory networks.

WFABC: a Wright-Fisher ABC-based approach for inferring effective population sizes and selection coefficients from time-sampled data.

With novel developments in sequencing technologies, time-sampled data are becoming more available and accessible. Naturally, there have been efforts in parallel to infer population genetic parameters from these data sets. Here, we compare and analyse four recent approaches based on the Wright-Fisher model for inferring selection coefficients (s) given effective population size (N(e)), with simulated temporal data sets. Furthermore, we demonstrate the advantage of a recently proposed approximate Bayesian computation (ABC)-based method that is able to correctly infer genomewide average N(e) from time-serial data, which is then set as a prior for inferring per-site selection coefficients accurately and precisely. We implement this ABC method in a new software and apply it to a classical time-serial data set of the medionigra genotype in the moth Panaxia dominula. We show that a recessive lethal model is the best explanation for the observed variation in allele frequency by implementing an estimator of the dominance ratio (h).

Comparing the effects of genetic drift and fluctuating selection on genotype frequency changes in the scarlet tiger moth

One of the recurring arguments in evolutionary biology is whether evolution occurs principally through natural selection or through neutral processes such as genetic drift. A 60-year-long time series of changes in the genotype frequency of a colour polymorphism of the scarlet tiger moth, Callimorpha dominula, was used to compare the relative effects of genetic drift and variable natural selection. The analysis showed that most of the variation in frequency was the result of genetic drift. In addition, although selection was acting, mean fitness barely increased. This supports the 'Red Queen's hypothesis' that long-term improvements in fitness may not occur, because populations have to keep pace with changes in the environment.

Temperatures in the cothill habitat of Panaxia (Callimorpha) dominula L. (the scarlet tiger moth).

Temperatures were monitored in precisely the places in Cothill Fen in which larvae of Panaxia dominula pupate. At the critical time in June, the temperatures in the litter layer are diurnally often much higher than those used in previous constant temperature experiments. Moreover, the daily mean temperature in the shaded litter layer is also higher than the shaded air temperature at 0.4 m, both temperatures being higher than the estimate of 12 degrees C used as baseline by others. The effects of fluctuating temperatures in the natural habitat on the phenotypic expression of wing patterns of the moth appear to be minimal and do not parallel the results of laboratory experiments.

Dietary mixing in three generalist herbivores: nutrient complementation or toxin dilution?

We reared larvae of three generalist insect species on plants occurring in their habitats. Individuals of each species were kept either on mixed diets, or on each plant species separately. We measured food plant preference in the mixed-diet group and compared insect performance on single plants to the performance on the mixed diet. For all three insect species, food choice within the mixed-diet groups was non-random and delivered the best overall performance, thus fulfilling the criteria for self-selected diets. When a single diet was as good as the mixed diet for one particular aspect of performance (Adenostyles alliariae and Petasites albus for Miramella alpina; A. alliariae for Callimorpha dominula), it was never the most preferred food plant in the mixed-diet treatment. Whether the benefit achieved by mixing diets is due to nutrient complementation or toxin dilution, we argue that there is no easy way to distinguish between the two hypotheses on the basis of consumption and performance measurements, as has previously been proposed. From the interpretation of utilisation plots, the ANCOVA equivalent of nutritional indices, we were able to gain insight into where in the sequence from ingestion to growth (preingestive, predigestive or postdigestive) single diets caused differences from mixed diets. The elements of this control system which were influenced by single diets varied considerably, both within and between insect species. No food plant was toxic or deterrent to all experimental insect species; a food plant that caused consumption effects (preingestive) for one insect species could be dealt with metabolically (postdigestive) by another; different food plants could cause behavioural effects (preingestive), metabolic effects (postdigestive), or a combination of both effects, all within the same insect species. However, one generality did emerge: once a food was ingested, further growth-relevant effects occurred metabolically (postdigestive) rather than via differential egestion (digestibility).

Long-Term Studies of the medionigra Polymorphism in the Moth Panaxia dominula: A Critique

Monitoring of the medionigra polymorphism in the moth, Panaxia dominula, at Cothill, Oxfordshire, UK, provides one of the longest and most complete data series in ecological genetics, and has provided a cornerstone in the development of this discipline. Changes in frequency between generations were used as proof of the overriding importance of selection in the prolonged and often heated selection/drift debate between R. A. Fisher, E. B. Ford and Sewall Wright. Recently evidence has emerged which suggests that the study may be flawed, particularly since phenotype appears to be influenced by environment. We offer what we regard as a proof of the inadequacy of this polymorphism for demonstrating selection, since phenotype is largely determined by temperature during the late larval or pupal phase. Hence workers at Cothill were not recording genetic processes. Assumptions that the medionigra form occurred only at Cothill, and that gene flow never occurred between Cothill and neighbouring populations, also appear to be untrue. The long-term study at Cothill may remain as a landmark in the history of ecological genetics only by virtue of the cautionary lessons it may teach future workers in this field.

Mating attempts between the Scarlet Tiger Moth,Callimorpha dominula L., and the Cinnabar Moth,Tyria jacobaeae L. (Lepidoptera: Arctiidae), involve a common sex pheromone composition

It has been suggested that a common sex pheromone composition may account for interspecific sexual interactions observed with certain moths in the Arctiidae. In this study, it is demonstrated that the sex pheromones released by females of the Scarlet Tiger Moth,Callimorpha dominula L., and the Cinnabar Moth,Tyria jacobaeae L., have similar activities and elute at the same retention time on analysis by coupled gas chromatography (GC)-electrophysiology with males from each species. Peak enhancement on GC, chiral GC and coupled GC-mass spectrometry using authentic compounds show that the sex pheromone for bothC. dominula andT. jacobaeae is (3Z,6Z,9S,10R)-9,10-epoxyheneicosa-3,6-diene.

Effect of Temperature on the Expression of the Medionigra Phenotype of the Moth Panaxia dominula (Lepidoptera: Arctiidae)

The well-known medionigra polymorphism in the scarlet tiger moth, Panaxia dominula, occupies an unique position in the history of ecological genetics. Year to year changes in phenotype frequency at the Cothill (Oxfordshire) colony were too great to be explained by random genetic drift, and were used as evidence for selection in a prolonged and heated debate between, on one side, E. B. Ford and R. A. Fisher, and on the other, Sewall Wright. Here we report experiments which clearly demonstrate that expression at the medionigra locus is largely determined by temperature. Since the genotype is not necessarily recognizable from the phenotype, the long series of field scored samples from Cothill do not accurately record changes in the medionigra allele frequency from year to year. Hence interpretation of the data as evidence for selection is invalid.

The Medionigra Polymorphism in the Moth, Panaxia dominula (Lepidoptera: Arctiidae): A Critical Re-Assessment

In 1939, E. B. Ford and R. A. Fisher commenced a long-term study of the moth, Panaxia dominula, at Cothill, Oxfordshire, England. Each year the population size was estimated and the frequency of the phenotypically recognisable medionigra allele monitored; the work has continued for 54 years (54 breeding generations). Two artificial colonies were established, one in 1951, monitored irregularly until 1961, the other in 1961 which was apparently not examined again until re-discovered by us in 1989 (...) Here we present evidence that the primary data on P.dominula may be faulty. We argue that field scoring of the medionigra phenotype was inconsistant and that environmental effects (temperature variations and movement between colonies) could alter the expression of phenotypes to an extent that errors in scoring might have been considerable. Our re-assessment does not settle the selection/drift issue, but suggests (in retrospect) that the moth was a poor choice upon which to base what at times was a heated argument

Sequestration of pyrrolizidine alkaloids in several arctiid moths (Lepidoptera: Arctiidae)

Sequestration of dietary pyrrolizidine alkaloids (PA) by larvae and adults of six European arctiid moth species (Spilosoma lubricipeda, Arctia caja, Phragmatobia fuliginosa, Callimorpha dominula, Diacrisia sannio, andTyria jacobaeae) was investigated for comparison with the well-studied Asian arctiidCreatonotos transiens. Larvae of all species metabolized free PA bases into the respectiveN-oxides. Only adults ofA. caja, P. fuliginosa, andS. lubricipeda, but not their larvae, converted dietary 7(S)-heliotrine to 7(R)-heliotrine, a direct precursor of a male pheromone in some arctiids, 7(R)-hydroxydanaidal. The larval integument figures as the main storage site for resorbed alkaloids; only minor amounts were found in other tissues. In addition, a significant amount of alkaloid is deposited in the cocoon ofArctia caja; only traces of alkaloids could be found in the meconium and the exuviae of this species. A substantial part of the alkaloids fed was degraded to unknown, nonalkaloidal products.

The phenotype and frequency of f. medionigra of Panaxia dominula L. (Lepidoptera: Arctiidae) at Cothill, Oxfordshire, England, 1988-1991

New research at Cothill Fen and examination of E. B. Ford's field note-books have revealed much evidence of great variation in the expression of the medionigra form of Panaxia dominula L. Over the years there is a high probability that individual insects have been misclassified. While this casts doubts on the accuracy of the published frequencies of the medionigra form and hence of the medionigra allele, it seems unlikely that the errors will have any serious effect on the interpretations and principles of ecological genetics that the long-term study has revealed. It is clear that both the fore- and hindwings must be examined before a judgement can be made about the phenotype of any individual moth. The new work shows that the medionigra form remains at a low frequency at Cothill. The colony is flourishing, the population size in 1991 being the largest ever recorded.

The phenotype and frequency of f. medionigra of Panaxia dominula L. (Lepidoptera: Arctiidae) at Cothill, Oxfordshire, England, 1988-1991

New research at Cothill Fen and examination of E. B. Ford's field note-books have revealed much evidence of great variation in the expression of the medionigra form of Panaxia dominula L. Over the years there is a high probability that individual insects have been misclassified. While this casts doubts on the accuracy of the published frequencies of the medionigra form and hence of the medionigra allele, it seems unlikely that the errors will have any serious effect on the interpretations and principles of ecological genetics that the long-term study has revealed. It is clear that both the fore- and hindwings must be examined before a judgement can be made about the phenotype of any individual moth. The new work shows that the medionigra form remains at a low frequency at Cothill. The colony is flourishing, the population size in 1991 being the largest ever recorded.

Natural selection and the scarlet tiger moth, Panaxia dominula : inconsistencies in the scoring of the heterozygote, f. medionigra

In 1989 we rediscovered an artificial colony of the scarlet tiger moth Panaxia dominula , started in 1961 by Philip Sheppard at West Kirby in the Wirral (well outside the normal range of the moth) and it had been undisturbed for many years (Clarke et al . 1990). The founding stock of 13000 back cross caterpillars came from Cothill, near Oxford, and in 1989 at West Kirby the proportions of the three phenotypes (typical, medionigra and bimacula , figure 1) were in the same Hardy-Weinberg equilibrium as they would have been had there been random mating and no selection (see table 1). This was in marked contrast to what had been reported at Cothill, a much bigger colony, researched for fifty years and characterized by great fluctuations in gene frequency and usually strong selection against medionigra (summarized by Jones (1989)). In the present paper we suggest that one factor contributing to the Cothill findings may have been variability in the scoring of medionigra by different observers over many years. The evidence for this comes first from two Cothill experts, and second from our own test matings using Wirral Way material.

50 years of studying the scarlet tiger moth

A growing number of long-term studies in plant and animal ecological genetics is now rewarding the patience, perseverance and perspicacity of those involved. A handful have involved work spanning 30 years and more, with an initial major impact on the way the study of population biology has developed. It is 50 years since investigation of the medionigra form of the scarlet tiger moth began, and in spite of very low allele frequencies and population numbers the medionigra allele persists in the original population. It is only by such long-term studies that we will be able to obtain more than just a cursory understanding of what really happens in natural populations of plants and animals.

The effects of random selection on gene frequency

The equations satisfied by the gene frequwncy for various cases of dominance are converted to the type of stochastic differential equation associated with a diffusion process. Using the physical approach to stochastic integrals, the solutions of the corresponding Fokker-Planck equations are obtained. Conditions for quasifixation are investigated and observed frequencies of the gene medionigra of Panaxia dominula are considered in relation to the model of random selection without dominance.

ASSORTATIVE POLLINATION FOR STATURE IN LYTHRUM SALICARIA.

Several traits in animals, especially color and size, are known to induce some form of preference for mating between similar organisms (assortment) or between dissimilar organisms (disassortment). Assortative mating has been demonstrated in laboratory populations of Drosophila (Merrell, 1949; Rendel, 1944, 1951; Parsons, 1965) and natural populations of the BlueSnow Goose (Cooch and Beardmore, 1959; Cook and Cooch, 1968), Arctic Skua (O'Donald, 1959; Berry and Davis, 1970), and man (Spuhler, 1968). A tendency for disassortative mating has been observed in the moths Panaxia dominula (Kettlewell, 1942; Sheppard, 1952), Biston betularia (Kettlewell, 1956), and Amanthes glareosa (Kettlewell and Berry, 1961), and the white throated sparrow Zonotrichia albicollis (Lowther, 1961). Assortative pollination or mating in bior polymorphic populations of plants has not been reported. This void ostensibly is due to the lack of interest and observations in assortment by pollination biologists, rather than the absence of the practice. Assortative pollination for qualitative floral characters is a distinct possibility in zoophilous plants. It is well known that pollinators, especially bees, butterflies and hummingbirds, can discriminate between alternative floral signals such as color, scent and corolla configuration (cf., Faegri and van der Pijl, 1966). In addition, these pollinators often remain constant to a single food image in spite of the presence of alternative and suitable images which may be closely related species. If pollinators were to apply the same foraging tactics within a polymorphic population as they do in an as-