Wing Spot Research Articles

The Study of Genetics of Flower Color in Faba Bean Reveals Generous Diversity to Be Used in the Horticulture Industry

The horticulturally valuable traits of faba bean are poorly explored, including the available information on the genetics of flower color and pattern. This lack of understanding has reduced the inclusion of unique flower color into the horticultural-type faba bean market. The modes of inheritance of two flower colors (red petals and yellow spot on wing petals) were examined through the development of multiple F2 segregating populations. The inheritance of red flower was confirmed for two recessive genes and yellow wing spot inheritance was confirmed for a single recessive gene. These populations led to the discovery of combinations of red and yellow flower color that have not been previously reported. The solid wing petal color gene was confirmed as a single recessive gene. Understanding the inheritance of flower color in faba bean can lead to improvement of current vegetable types and opens up possibilities for ornamental markets.

Genotoxic analysis of nickel–iron oxide in Drosophila

It is known that nickel-iron oxide nanocomposite (NiFe2O4NP) is used in many important areas such as modern industry, biomedical applications, magnetic resonance imaging, construction of sensors, targeted drug treatment, and photoelectric devices in our life. In this study, we have carried out a genotoxic evaluation of NiFe2O4NP (30 nm) in Drosophila melanogaster by using the wing somatic mutation and recombination assay. For this purpose, third instar larvae carrying the recessive genes (flr3) and multiple wing hairs (mwh) in their third chromosomes were used. The larvae were fed at concentrations ranging from 25 µg/mL to 200 µg/mL. The genotoxic effects of NiFe2O4NPs were evaluated according to mutant trichomes resulting from genetic changes (mitotic recombination, deletion, point mutation, nondisjunction) on development of the wing imaginal discs. Mutant clone evaluations were performed based on small single spots, large single spots, and twin spots classifications. The results showed that significant increases were observed in the frequency of all spots, indicating that the highest concentration of nanoparticles was able to induce genotoxic activity in the wing spot assay of D. melanogaster.

Sperm Morphology and Male Age in Black-Throated Blue Warblers, an Ecological Model System.

Simple SummarySperm cell characteristics can impact the number of offspring a male sires, particularly when females copulate with more than one male in a reproductive cycle. Females copulate with multiple males in many songbird species, but for many of these species, little is known about sperm characteristics. In this paper, we examine the shape of sperm cells in black-throated blue warblers, a species where multiple copulations are common but where sperm morphology was previously unknown. Sperm shape did not correlate with plumage characteristics that may make males more successful at gaining copulation partners. However, older males tended to have longer sperm cells. Previous work shows that older males sire more offspring, and work in other species indicates that longer sperm cells are more effective at fertilizing eggs. Thus, sperm shape may help explain the higher success of older males in this species. Extra-pair paternity may drive selection on spermatozoa and ejaculate characteristics through sperm competition and cryptic female choice. Here, we examine sperm morphology in the black-throated blue warbler (Setophaga caerulescens), an ecological model species where extra-pair paternity is frequent and is linked with male age. We test whether sperm morphology relates to several aspects of male phenotype known or suspected to affect extra-pair paternity success. Sperm morphology did not correlate with the size of the white wing spot, a social status signal, nor with the volume of the cloacal protuberance. However, older males tended to have longer sperm cells. Although the sample size was limited, this pattern is intriguing, as longer cells may be advantageous in post-copulatory sexual selection and older males have larger testes and higher extra-pair paternity success in this species. Changes in sperm morphology with age are not observed in other birds, though they have been observed in insects and fishes. More research on sperm morphology is needed to clarify its role in extra-pair fertilizations in this well-studied species.

Hydroxyapatite nanoparticle causes sensory organ defects by targeting the retromer complex in Drosophila melanogaster

Hydroxyapatite nanoparticles are utilized extensively in the era of nanotechnology to deliver various drugs to the right area. However, the molecular mechanism behind the transportation of these nanoparticles and its effect on the development and maintenance of sensory organs is not known. The current study aims to check the effect of hydroxyapatite nanoparticle (HApNP) on sensory organs of Drosophila. Various concentrations of HApNP (10 mg·L−1, 20 mg·L−1, 40 mg·L−1 and 80 mg·L−1) were mixed with fly food and the developmental defects were monitored. Sensory organs like the eye and the mechanosensory organs were studied in a developmental time window. The larval eye-antennae and wing imaginal discs were checked for apoptotic cell death. In pupae, the damage becomes more prominent and it persists till adult. In the adult fly, the eye with a fused facet, defective cone and rhabdomere appear. Similarly, the wing with wing spots, macrochaetae, and defective alignment of hairs were also observed. All these phenotypic defects suggest the mistargeting of various proteins involved in the development. The current study correlates the phenotypic defects observed in the eye and wing is due to the down-regulation of the genes associated with the retromer complex.

Co-evolving wing spots and mating displays are genetically separable traits in Drosophila.

The evolution of sexual traits often involves correlated changes in morphology and behavior. For example, in Drosophila, divergent mating displays are often accompanied by divergent pigment patterns. To better understand how such traits co-evolve, we investigated the genetic basis of correlated divergence in wing pigmentation and mating display between the sibling species Drosophila elegans and Drosophila gunungcola. Drosophila elegans males have an area of black pigment on their wings known as a wing spot and appear to display this spot to females by extending their wings laterally during courtship. By contrast, D. gunungcola lost both of these traits. Using Multiplexed Shotgun Genotyping (MSG), we identified a ∼440 kb region on the X chromosome that behaves like a genetic switch controlling the presence or absence of male-specific wing spots. This region includes the candidate gene optomotor-blind (omb), which plays a critical role in patterning the Drosophila wing. The genetic basis of divergent wing display is more complex, with at least two loci on the X chromosome and two loci on autosomes contributing to its evolution. Introgressing the X-linked region affecting wing spot development from D. gunungcola into D. elegans reduced pigmentation in the wing spots but did not affect the wing display, indicating that these are genetically separable traits. Consistent with this observation, broader sampling of wild D. gunungcola populations confirmed that the wing spot and wing display are evolving independently: some D. gunungcola males performed wing displays similar to D. elegans despite lacking wing spots. These data suggest that correlated selection pressures rather than physical linkage or pleiotropy are responsible for the coevolution of these morphological and behavioral traits. They also suggest that the change in morphology evolved prior to the change in behavior.

Hetaerina calverti (Odonata: Zygoptera: Calopterygidae) sp. nov., a new cryptic species of the American Rubyspot complex.

Hetaerina americana Fabricius, 1798 has a long and irresolute taxonomic history. Several synonyms have been suggested (H. californica Hagen in Selys-Longchamps, 1859, H. basalis Hagen in Selys-Longchamps, 1859, H. texana Walsh, 1863, H. scelerata Walsh, 1863, etc.), related to the variation in the size of the wing spots as well as to the morphology of the male cerci. However, Calvert (1901) suggested that H. americana represents one variable species. Nevertheless, Vega-Sánchez et al. (2019) through a genetic and morphological analysis presented evidence to propose that H. americana represents a species complex. In the present work, we describe a new species that belongs to this complex: H. calverti sp. nov. The morphological characteristics by which males and females of H. calverti differ from H. americana are highlighted. The most important character for the differentiation of males is the shape of the cerci and the size of the individuals (when the two species are in sympatry). In females, the main differences are in the shape of the intersternites and the medio-dorsal carina of the last segment of the abdomen. Some generalities about the biology of the species are presented, including geographical distribution patterns and genetic divergence data. [urn:lsid:zoobank.org:act:F5C329AE-7A00-4979-8A0D-A13D869E54B1].

Drosophila suzukii wing spot size is robust to developmental temperature.

Phenotypic plasticity is an important mechanism allowing adaptation to new environments and as such it has been suggested to facilitate biological invasions. Under this assumption, invasive populations are predicted to exhibit stronger plastic responses than native populations. Drosophila suzukii is an invasive species whose males harbor a spot on the wing tip. In this study, by manipulating developmental temperature, we compare the phenotypic plasticity of wing spot size of two invasive populations with that of a native population. We then compare the results with data obtained from wild‐caught flies from different natural populations. While both wing size and spot size are plastic to temperature, no difference in plasticity was detected between native and invasive populations, rejecting the hypothesis of a role of the wing‐spot plasticity in the invasion success. In contrast, we observed a remarkable stability in the spot‐to‐wing ratio across temperatures, as well as among geographic populations. This stability suggests either that the spot relative size is under stabilizing selection, or that its variation might be constrained by a tight developmental correlation between spot size and wing size. Our data show that this correlation was lost at high temperature, leading to an increased variation in the relative spot size, particularly marked in the two invasive populations. This suggests: (a) that D. suzukii's development is impaired by hot temperatures, in agreement with the cold‐adapted status of this species; (b) that the spot size can be decoupled from wing size, rejecting the hypothesis of an absolute constraint and suggesting that the wing color pattern might be under stabilizing (sexual) selection; and (c) that such sexual selection might be relaxed in the invasive populations. Finally, a subtle but consistent directional asymmetry in spot size was detected in favor of the right side in all populations and temperatures, possibly indicative of a lateralized sexual behavior.

Reuse of voucher specimens provides insights into the genomic associations and taxonomic value of wing colour and genitalic differences in a pest group (Lepidoptera: Tortricidae: Choristoneura)

AbstractSubtle morphological differences can be essential to diagnosing closely related species, and an understanding of the genetic basis of these characters can contribute to understanding their divergences. We used voucher specimens from previous genetic analyses of population structure to subsequently analyse genome‐wide associations linking morphology to genetic variation in spruce budworms, a group of economically important and morphologically similar forest pests. In particular, we assessed the taxonomic value and genetic architecture of two morphological traits (wing pattern and genitalic spicule abundance) that have been reported to differ among spruce budworm species. Our results suggest that phallic spicule number has greater taxonomic utility than wing pattern for distinguishing Choristoneura fumiferana (Clemens) from Choristoneura occidentalis occidentalis Freeman and Choristoneura occidentalis biennis Freeman. However, there was considerable overlap among taxa for all phenotypic characters analysed. In a genome‐wide association study, wing pattern variation was significantly associated with four single nucleotide polymorphism (SNP) loci, including two adjacent SNPs. One SNP was flanked by sequence resembling RNA‐directed DNA polymerase from mobile element jockey‐like. This locus is a promising candidate for the study of wing pattern development in spruce budworms, as jockey‐like transposable elements and polymerases have documented roles in wing spot production in other Lepidoptera. Our study links classical taxonomic characters and genomic data to provide insights into the potential genetic architecture of species differences. It also demonstrates previously untapped morphological and taxonomic value in voucher specimens from earlier molecular genetic analyses.

Evolution of Reproductive Behavior.

Behaviors associated with reproduction are major contributors to the evolutionary success of organisms and are subject to many evolutionary forces, including natural and sexual selection, and sexual conflict. Successful reproduction involves a range of behaviors, from finding an appropriate mate, courting, and copulation, to the successful production and (in oviparous animals) deposition of eggs following mating. As a consequence, behaviors and genes associated with reproduction are often under strong selection and evolve rapidly. Courtship rituals in flies follow a multimodal pattern, mediated through visual, chemical, tactile, and auditory signals. Premating behaviors allow males and females to assess the species identity, reproductive state, and condition of their partners. Conflicts between the “interests” of individual males, and/or between the reproductive strategies of males and females, often drive the evolution of reproductive behaviors. For example, seminal proteins transmitted by males often show evidence of rapid evolution, mediated by positive selection. Postmating behaviors, including the selection of oviposition sites, are highly variable and Drosophila species span the spectrum from generalists to obligate specialists. Chemical recognition features prominently in adaptation to host plants for feeding and oviposition. Selection acting on variation in pre-, peri-, and postmating behaviors can lead to reproductive isolation and incipient speciation. Response to selection at the genetic level can include the expansion of gene families, such as those for detecting pheromonal cues for mating, or changes in the expression of genes leading to visual cues such as wing spots that are assessed during mating. Here, we consider the evolution of reproductive behavior in Drosophila at two distinct, yet complementary, scales. Some studies take a microevolutionary approach, identifying genes and networks involved in reproduction, and then dissecting the genetics underlying complex behaviors in D. melanogaster. Other studies take a macroevolutionary approach, comparing reproductive behaviors across the genus Drosophila and how these might correlate with environmental cues. A full synthesis of this field will require unification across these levels.

Body mass and territorial defence strategy affect the territory size of odonate species.

The territory is a distinct mating place that a male defends against intruding conspecific males. The size of a territory varies between species and most of the variation between species has been found to scale allometrically with body mass. The variation that could not be explained by body mass has been explained with several variables such as habitat productivity, trophic level, locomotion strategy and thermoregulation. All previous interspecific comparative studies have been done on vertebrate species such as birds, mammals, reptiles and fishes, meaning that studies using invertebrate species are missing. Here, we studied the relationship of a species's territory size with its fresh body mass (FBM) in addition to other ecologically relevant traits using 86 damselfly and dragonfly (Odonata) species. We found that territory size is strongly affected by species FBM, following an allometric relationship similar to vertebrates. We also found that the territory size of a species was affected by its territorial defence strategy, constantly flying species having larger territories than species that mostly perch. Breeding habitat or the presence of sexual characters did not affect territory sizes, but lotic species and species without wing spots had steeper allometric slopes. It seems that an increase in a species's body mass increases its territory size and may force the species to shift its territory defence strategy from a percher to a flier.

Oral administration of graphene oxide nano-sheets induces oxidative stress, genotoxicity, and behavioral teratogenicity in Drosophila melanogaster.

The current study checks the effect of various concentrations of dietary graphene oxide (GO) nano-sheets on the development of Drosophila melanogaster. GO was synthesized and characterized by XRD, FTIR, FESEM, and TEM analytical techniques. Various concentrations of GO were mixed with the fly food and flies were transferred to the vial. Various behavioral and morphological as well as genetic defects were checked on the different developmental stages of the offspring. In the larval stage of development, the crawling speed and trailing path change significantly than the control. GO induces the generation of oxygen radicals within the larval hemolymph as evidenced by nitroblue tetrazolium assay. GO induces DNA damage within the gut cell, which was detected by Hoechst staining and within hemolymph by comet assay. Adult flies hatched after GO treatment show defective phototaxis and geotaxis behavior. Besides behavior, phenotypic defects were observed in the wing, eye, thorax bristles, and mouth parts. At 300 mg/L concentration, wing spots were observed. Altogether, the current study finds oral administration of GO which acts as a mutagen and causes various behavioral and developmental defects in the offspring. Here for the first time, we are reporting GO, which acts as a teratogen in Drosophila, besides its extensive medical applications.

HERBICIDE GENOTOXICITY REVEALED WITH THE SOMATIC WING SPOT ASSAY OF Drosophila melanogaster

The genotoxicity of the herbicides clomazone, linuron and simazine was detected using the somatic wing spot assay of Drosophila melanogaster . For the evaluation of the mutagenic and recombinogenic activities induced by the herbicides two crosses were used: the standard cross (ST) which expresses basal levels of cytochrome P450 enzymes and the high bioactivation cross (HB) with overexpression of P450 genes conferring increased sensitivity to promutagens and procarcinogens. Third-instar larvae were exposed by chronic feeding (48 h) to three different concentrations of each herbicide. The frequencies of spots per individual in the treated series were compared to the negative concurrent control series (water or 5 % ethanol solution depending on the herbicide). Clomazone showed positive results for small and total spots in both the ST and the HB crosses. Linuron was positive at all concentrations tested for small and total spots in the ST cross while only positive for small and total spots at the highest concentration assayed in the HB cross. Simazine did not produce positive results in the ST cross while it was positive in the HB cross. The bifunctional cross-linking agent mitomycin C (MMC – 0.15 mM) was used as positive control and produced as expected a significant increase of all types of spots in both crosses. In conclusion, the positive results were due to induced mutations and not by recombinogenic activity, furthermore the significant increase in the frequency of total spots was mainly due to the induction of small single spots.

DDC plays vital roles in the wing spot formation, egg production, and chorion tanning in the brown planthopper.

The gene dopa decarboxylase (Nlddc) of the brown planthopper (BPH, Nilaparvata lugens) was identified in the genome and transcriptome of the insect. The open reading frame of Nlddc is 1,434 bp in length and, it has the potential to encode a protein of 477 amino acid with a conserved pyridoxal-dependent decarboxylase domain and a typical motif, NFNPHKW. Real-time quantification polymerase chain reaction analyses revealed that this gene was highly expressed in the integument and brain, and transcript level peaked in the late stages of egg period and each nymph instar with periodicity. RNA interference results revealed that Nlddc played essential roles in pigment synthesis, formation of wing spot, egg production, and tanning of the chorion. A rapid accumulation of Nlddc transcripts was detected, and it coincided with the injection of the hormone 20-hydroxyecdysone (20E), suggesting that Nlddc transcription was regulated by 20E.

Continent‐scale phenotype mapping using citizen scientists’ photographs

Field investigations of phenotypic variation in free‐living organisms are often limited in scope owing to time and funding constraints. By collaborating with online communities of amateur naturalists, investigators can greatly increase the amount and diversity of phenotypic data in their analyses while simultaneously engaging with a public audience. Here, we present a method for quantifying phenotypes of individual organisms in citizen scientists’ photographs. We then show that our protocol for measuring wing phenotypes from photographs yields accurate measurements in two species of Calopterygid damselflies. Next, we show that, while most observations of our target species were made by members of the large and established community of amateur naturalists at iNaturalist.org, our efforts to increase recruitment through various outreach initiatives were successful. Finally, we present results from two case studies: 1) an analysis of wing pigmentation in male smoky rubyspots Hetaerina titia showing previously undocumented geographical variation in a seasonal polyphenism, and 2) an analysis of variation in the relative size of the wing spots of male banded demoiselles Calopteryx splendens in Great Britain questioning previously documented evidence for character displacement. Our results demonstrate that our protocol can be used to create high quality phenotypic datasets using citizen scientists’ photographs, and, when combined with metadata (e.g. date and location), can greatly broaden the scope of studies of geographical and temporal variation in phenotypes. Our analyses of the recruitment and engagement process also demonstrate that collaborating with an online community of amateur naturalists can be a powerful way to conduct hypothesis‐driven research aiming to elucidate the processes that impact trait evolution at landscape scales.

Mutagenic and recombinogenic assessment of widely used pesticides on Drosophila melanogaster

The mutagenic potential of selected widely used pesticides: p,p'-dichlorodiphenyltrichloroethane (DDT); fenitrothion; propoxur; deltamethrin, bifenthrin; imidacloprid and thiametoxam was assessed using the wing spot test. Third-instar larvae of standard Drosophila melanogaster cross (ST), trans-heterozygous for the third chromosome recessive markers, multiple wing hairs (mwh) and flare (flr3) were chronically exposed to test compounds. Feeding ended with pupation of the surviving larvae. Genetic changes induced in somatic cells of the wing’s imaginal discs, mutant spots observed in marker-heterozygous (MH) and balancer-heterozygous (BH) flies were compared using the wing spot test, to estimate the genotoxic effects of these pesticides. In conclusion, exposure to 30 mg/mL deltamethrin, 40 mg/mL imidacloprid, 100 µg/mL DDT showed mutagenic and recombinagenic effects in the Drosophila wing spot test. In addition the results of chronic treatments performed at high doses showed mutagenic and recombinagenic effects in both genotypes

Evidence for adaptive constraints on size of marginal wing spots in the grayling butterfly,Hipparchia semele

Evidence for adaptive constraints on size of marginal wing spots in the grayling butterfly,<i>Hipparchia semele</i>

Assessing the use of wing ornamentation and visual display in female choice sexual selection

Conspicuous sexual dimorphism is often ascribed to sexual selection. When the differences between the sexes are ornamental, this is thought to indicate a role for female choice. In spotted winged Drosophila species courtship, a male positioned in front of a female waves his wings, which have a patch of melanization on the exterior margin. In this study, we examine both female preference for wing spots and the role of vision in mating success in three species of the suzukii group: Drosophila biarmipes, D. suzukii, and D. subpulchrella. To assess female preference for wing spot, we removed the spot with a novel, non-invasive method, and competed spotless males with males with two spots. Phenotype did not affect mating success in any species. To eliminate the potential effect of competitive behavior on male mating success, we also ran a no-choice analysis. Mating frequency and timing was not different between phenotypes within these species. The effect of vision on mating success was assessed by comparing mating success of spotted males between light and dark conditions, both for frequency of mating, as well as timing of multiple courtship parameters. Species varied in the extent that lack of vision negatively affected mating success. Though vision is important for mating success, the spot itself may not be providing the signal that females use to make mating decisions.

In vitro and in vivo evaluation of the genotoxic and antigenotoxic potential of the major Chios mastic water constituents

Chios mastic products are well-known for their broad applications in food industry, cosmetics, and healthcare since the antiquity. Given our recent finding that Chios mastic water (CMW) exerts antigenotoxic action, in the present study, we evaluated the genotoxic as well as the antigenotoxic potential of the four major compounds of CMW, namely, verbenone, α-terpineol, linalool, and trans-pinocarveol. The cytokinesis block micronucleus (CBMN) assay in cultured human lymphocytes and the Drosophila Somatic Mutation And Recombination Test (SMART), also known as the wing spot test, were employed. None of the four major CMW’s constituents or their mixtures showed genotoxic or recombinogenic activity in either of the assays used. Co-treatment of each of the constituents with MMC revealed that all except trans-pinocarveol exerted antigenotoxic potential. Moreover, co-administration of verbenone with linalool or α-terpineol presented statistically significant reduction of MMC-induced mutagenicity. In conclusion, the major CMW constituents were shown to be free of genotoxic effects, while some exerted antigenotoxic activity either alone or in combinations, suggesting synergistic phenomena. Our results provide evidence on the key antigenotoxicity effectors of the plant extract CMW.

Anti/genotoxic, longevity inductive, cytotoxic, and clastogenic-related bioactivities of tomato and lycopene.

The aim of this study was to evaluate some biological activities of tomato as well as lycopene and to consider a new nutraceutic value for this fruit regarding to the protection against genetic damage and as a chemopreventive agent. Genotoxicity, DNA-protection against hydrogen peroxide, and lifespan properties of tomato and lycopene were assessed through wing spot test and longevity assay using the Drosophila in vivo model. Additionally, chemopreventive activity was investigated through cytotoxicity, DNA-fragmentation comet and annexin V FITC/PI assays using HL60 in vitro model. Results showed that: (i) tomato and lycopene are not genotoxic and protect against H2 O2 -induced damage; (ii) with respect to the lifespan, tomato and lycopene are harmless at the lowest concentration; (iii) tomato is cytotoxic in a dose-dependent manner, but not lycopene; (iv) tomato and lycopene do not induce internucleosomal DNA-fragmentation although they induce significant clastogenic activity at low level in the leukemia cells. To sum up, tomato is a good candidate to be considered as a nutraceutical substance. Furthermore, synergistic action among other components within tomato matrix could be the cause of the health effects observed in this vegetable, which are not fully explained by lycopene. Environ. Mol. Mutagen. 59:427-437, 2018. © 2018 Wiley Periodicals, Inc.

Sexual signals reveal males’ oxidative stress defences: Testing this hypothesis in an invertebrate

Abstract The hypothesis that sexual traits reveal the oxidative stress resistance of their bearers has been widely tested in vertebrates but remains unexplored in invertebrates. Here, Hetaerina americana was used to test whether oxidative stress defences are advertised by male wing spot size and colour (a male sexual trait). To this end, we investigated (1) whether oxidative stress reduced survival, (2) whether wing spot size revealed males’ antioxidant defences and (3) how wing spot size and colour were affected by oxidative stress. We elevated oxidative stress by injecting adult males with paraquat (PQ, a compound that favours the production of free radicals) and then examined how this affected male survival and wing spot size. We then related the expression of wing spot size to indicators of oxidative stress—hydrogen peroxide (H2O2) and total antioxidant capacity (TAC), super oxide dismutase (SOD) and catalase (CAT)—in adult males (whose wing spot is fixed) injected with PQ. In teneral males, whose wing spots are still forming, we compared wing spot size, colour (red and yellow chroma) and brightness in individuals injected with PQ or water as a control. Oxidative stress reduced the survival of adult and teneral males. While the H2O2 and TAC markers of antioxidant defences were positively correlated with wing spot size, there was no correlation with CAT and a negative correlation with SOD. In teneral males, PQ increased the yellow chroma and brightness of wing spots, but did not affect spot size or red chroma. Our results highlight the importance of measuring different markers as indicators of male oxidative stress defences, and that the sexual signals of invertebrates may reveal the oxidative stress status of their bearers. A plain language summary is available for this article.