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In the present paper, karyotypes of 7 Japanese Podismini species, Anapodisma beybienkoi, Fruhstorferiola okinawaensis, Parapodisma caelestis, P. mikado, P. setouchiensis, P. tenryuensis, and Sinopodisma punctata (2nâ = 21, all acrocentric), are described and compared on the basis of conventional (C-banding, DAPI/CMA3-staining, Ag-NOR) and molecular (FISH with 18S rDNA and telomeric probes) cytogenetic staining methods. This is the first study to report karyotypes of A. beybienkoi and P. caelestis. Differential staining techniques showed karyotypic diversity in these species. The number of 18S rDNA signals ranged from 2 to 6, and the signals were located on the autosomes or sex chromosomes. In all species, clusters of rDNA coincided with Ag-NORs. Telomeric signals occurred at the chromosome ends at the pachytene stage and seldom at other stages of meiosis. Paracentromeric and some distal and interstitial blocks of constitutive heterochromatin were detected in the chromosomes of Anapodisma, Fruhstorferiola, and Parapodisma species. Staining with DAPI and CMA3 revealed 2 groups of heterochromatin composition. In addition, intraspecific differences in the number of rDNA clusters and C-bands were observed within Parapodisma species. Based on the evidence of cytogenetic characteristics, the monophyly of Tonkinacridina cannot be supported.
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Mapeamento Cromossômico/métodos , Gafanhotos/genética , Cariotipagem/métodos , Animais , Bandeamento Cromossômico , DNA Ribossômico/genética , Variação Genética , Gafanhotos/classificação , Hibridização in Situ Fluorescente , Masculino , Filogenia , RNA Ribossômico 16S/genéticaRESUMO
BACKGROUND: Poecilimon and Isophya are the largest genera of the tribe Barbitistini and among the most systematically complicated and evolutionarily intriguing groups of Palearctic tettigoniids. We examined the genomic organization of 79 taxa with a stable chromosome number using classical (C-banding, silver and fluorochrome staining) and molecular (fluorescence in situ hybridization with 18S rDNA and (TTAGG)n telomeric probes) cytogenetic techniques. These tools were employed to establish genetic organization and differences or similarities between genera or species within the same genus and determine if cytogenetic markers can be used for identifying some taxonomic groups of species. RESULTS: Differences between the karyotypes of the studied genera include some general changes in the morphology of the X chromosome in Isophya (in contrast to Poecilimon). The number of major rDNA clusters per haploid genome divided Poecilimon into two main almost equal groups (with either one or two clusters), while two rDNA clusters predominated in Isophya. In both genera, rDNA loci were preferentially located in the paracentromeric region of the autosomes and rarely in the sex chromosomes. Our results demonstrate a coincidence between the location of rDNA loci and active NORs and GC-rich heterochromatin regions. The C/DAPI/CMA3 bands observed in most Poecilimon chromosomes suggest the presence of more families of repetitive DNA sequences as compared to the heterochromatin patterns in Isophya. CONCLUSIONS: The results show both differences and similarities in genome organization among species of the same genus and between genera. Previous views on the systematics and phylogenetic grouping of certain lineages are discussed in light of the present cytogenetic results. In some cases, variation of chromosome markers was observed to correspond with variation in other evolutionary traits, which is related to the processes of ongoing speciation and hybridization in zones of secondary contact. It was concluded that the physical mapping of rDNA sequences and heterochromatin may be used as an additional marker for understanding interspecific relationships in these groups and their routes of speciation.
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Gryllidae/classificação , Gryllidae/genética , Animais , Mapeamento Cromossômico , Cromossomos de Insetos , DNA Ribossômico/genética , Feminino , Heterocromatina , Hibridização in Situ Fluorescente , Masculino , FilogeniaRESUMO
A critical review of the taxonomy and systematics of the genus Isophya from the Balkan Peninsula, together with a revision of the I. modesta group, including its representatives outside the Balkans, has been made using morphological, bioacoustic and karyological data. As a result, the following taxonomic considerations have been proposed: (1) the status of two taxa has been reconsidered: Isophya rhodopensis leonorae Kaltenbach, stat.n., I. rhodopensis petkovi Peshev, stat.n.; (2) five synonymies have been established: I. hospodar (Saussure) = I. hospodar medimontana Nedelkov, syn.n.; I. plevnensis Peshev, sensu novo = I. pravdini pravdini Peshev, syn.n.; I. rhodopensis leonorae Kaltenbach = I. kisi Peshev, syn.n.; I. obtusa = I. pravdini bazyluki Peshev, syn.n.; I. modesta Frivaldszky = I. modesta intermedia Kis syn.n. The descriptions of the taxa under consideration are supplemented with unpublished morphological and/or bioacoustic data. An updated list of the taxa occurring on the Balkans includes 24 taxa (21 species, including the doubtful data on I. camptoxypha). A dichotomic and tabulated key for recognition and maps of distribution of the established taxa are presented.
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Ortópteros/classificação , Ortópteros/fisiologia , Animais , Feminino , Masculino , Ortópteros/anatomia & histologia , Vocalização AnimalRESUMO
Genetic variability between populations of the orthopteran insect Tetrix tenuicornis, collected from six locations in Poland, was assayed by using the random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) method. The results show that insects in a population from metal polluted areas in Boleslaw have reduced genetic variability in contrast to five other populations located in unpolluted areas. The insects from polluted sites also showed significant changes in elemental concentrations in nerve and muscle cells, measured by X-ray spectroscopy, when compared to insects of the same species collected from unpolluted sites.
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Poluentes Ambientais/toxicidade , Variação Genética , Ortópteros/genética , Animais , Sequência de Bases , Primers do DNA , Microanálise por Sonda Eletrônica , Reação em Cadeia da Polimerase , Polimorfismo Genético , Técnica de Amplificação ao Acaso de DNA PolimórficoRESUMO
COVID-19 expanded rapidly throughout the world, with enormous health, social, and economic consequences. Mental health is the most affected by extreme negative emotions and stress, but it has been an underestimated part of human life during the pandemic. We hypothesized that people may have responded to the pandemic spontaneously with increased interest in and creation of funny internet memes. Using Google and Google Trends, we revealed that the number of and interest in funny internet memes related to COVID-19 exploded during the spring 2020 lockdown. The interest in coronavirus memes was positively correlated with interest in mortality due to COVID-19 on a global scale, and positively associated with the real number of deaths and cases reported in different countries. We compared content of a random sample of 200 coronavirus memes with a random sample of 200 non-coronavirus memes found on the Internet. The sentiment analysis showed that coronavirus memes had a similar proportion of positive and negative words compared to non-coronavirus memes. However, an internet questionnaire revealed that coronavirus memes gained higher funniness scores than a random sample of non-coronavirus memes. Our results confirm that societies may have turned to humor to cope with the threat of SARS-CoV-2.
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COVID-19 , Pandemias , COVID-19/epidemiologia , Controle de Doenças Transmissíveis , Humanos , Saúde Mental , SARS-CoV-2RESUMO
Why do some species occur in small, restricted areas, while others are distributed globally? Environmental heterogeneity increases with area and so does the number of species. Hence, diverse biotic and abiotic conditions across large ranges may lead to specific adaptations that are often linked to a species' genome size and chromosome number. Therefore, a positive association between genome size and geographic range is anticipated. Moreover, high cognitive ability in organisms would be favored by natural selection to cope with the dynamic conditions within large geographic ranges. Here, we tested these hypotheses in birds-the most mobile terrestrial vertebrates-and accounted for the effects of various confounding variables, such as body mass, relative brain mass, and geographic latitude. Using phylogenetic generalized least squares and phylogenetic confirmatory path analysis, we demonstrated that range size is positively associated with bird genome size but probably not with chromosome number. Moreover, relative brain mass had no effect on range size, whereas body mass had a possible weak and negative effect, and range size was larger at higher geographic latitudes. However, our models did not fully explain the overall variation in range size. Hence, natural selection may impose larger genomes in birds with larger geographic ranges, although there may be additional explanations for this phenomenon.
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The genus Poecilimon contains 145 species, widely distributed in the Palaearctic, among which the Poecilimon ornatus group has the greatest diversity in the Balkans. Despite several revisions of the genus, the systematics of the species group, and in particular, of the taxa associated with the species Poecilimon affinis, is still unsolved. Due to morphological similarity, P. affinis with its subspecies, P. nonveilleri and P. pseudornatus form the Poecilimon affinis complex. The aim of this study is to test the hypotheses of an outlined species complex, namely the P. affinis complex, within the P. ornatus group using morphological data. Geometric analysis was conducted to explore variation in the structure of the male tegmen, ovipositor, male cercus, and male pronotum. The number of teeth and stridulatory file measurements provided additional information on morphological variation within the complex. A phylogenetic tree based on the cytochrome c oxidase subunit I gene (COI) was used for comparison with the morphological data. Canonical variate analysis showed that male tegmen and male cercus are good morphostructures to distinguish the taxa belonging to the P. affinis complex from other species in the P. ornatus group. This may confirm our assumption for the designation of the P. affinis complex. The results of the principal component analysis of stridulatory file measurements, molecular data, and CVA of the ovipositor suggest adding two additional species to the complex: P. ornatus and P. hoelzeli.
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Ophiocordyceps fungi are commonly known as virulent, specialized entomopathogens; however, recent studies indicate that fungi belonging to the Ophiocordycypitaceae family may also reside in symbiotic interaction with their host insect. In this paper, we demonstrate that Ophiocordyceps fungi may be obligatory symbionts of sap-sucking hemipterans. We investigated the symbiotic systems of eight Polish species of scale insects of Coccidae family: Parthenolecanium corni, Parthenolecanium fletcheri, Parthenolecanium pomeranicum, Psilococcus ruber, Sphaerolecanium prunasti, Eriopeltis festucae, Lecanopsis formicarum and Eulecanium tiliae. Our histological, ultrastructural and molecular analyses showed that all these species host fungal symbionts in the fat body cells. Analyses of ITS2 and Beta-tubulin gene sequences, as well as fluorescence in situ hybridization, confirmed that they should all be classified to the genus Ophiocordyceps. The essential role of the fungal symbionts observed in the biology of the soft scale insects examined was confirmed by their transovarial transmission between generations. In this paper, the consecutive stages of fungal symbiont transmission were analyzed under TEM for the first time.
Assuntos
Hemípteros/anatomia & histologia , Hypocreales/fisiologia , Simbiose , Animais , Hemípteros/metabolismo , Hemípteros/fisiologia , Hemípteros/ultraestrutura , Hypocreales/genética , FilogeniaRESUMO
East African mountains constitute a network of isolated habitat islands among dry savannah and are thus ideal for studying species diversification processes. This study elucidated the phylogenetic and phylogeographic relationships of all bushcricket species comprising the genus Aerotegmina. Our analysis indicated that large-scale climatic and topographic processes in Africa are likely to have driven speciation in this group, and revealed the cytogenetic traits of the species. Molecular phylogeny supported the monophyly of Aerotegmina and showed that the genus probably originated in the old Eastern Arc Mountains of Tanzania and Kenya. Two lineages were distinguished: small- and large-sized species with geographically distinct habitats. The underlying processes are thought to be eight dispersals, ten vicariance events, and one extinction event linked to repeated fragmentation of the African rainforest. Those processes, in conjunction with habitat change, probably also led to the spatial separation of the species into a northern clade with a diploid number of chromosomes 2n = 32 + X0 or 2n = 30 + neo-XY and a southern clade with a reduced number of chromosomes (2n = 28 + X0 or 24 + neo-X1X2Y). Karyotype analysis suggests that Aerotegmina is currently in the process of speciation.
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East Africa is a hotspot of biodiversity of many orthopteran taxa, including bushcrickets. Gonatoxia Karsch, 1889 species are fully alate Phaneropterinae, which are perfectly adapted to the foliage of forests. We examined five species using combined cytogenetic and molecular data to determine the inter- and intraspecific genetic diversity. The variation in the diploid number of chromosomes in males ranged from 2n = 28 + X0 and 26 + X0 to 2n = 6 + X0. Fluorescence in situ hybridization showed from one to many 18S rDNA loci as well as interstitial sequences, especially in G. helleri. 18S rDNA loci coincided with active NOR and C-banding patterns. The isolation of populations of the species explains differences in the number of chromosomes (G. maculata), chromosomal polymorphism and chromosomal heterozygosity (G. helleri). Our molecular phylogeny based on the COI locus supported the monophyly of the genus Gonatoxia and separateness of the five examined species in accordance with their morphological features and chromosome numbers as well as the species' distribution.
Assuntos
Aberrações Cromossômicas , Código de Barras de DNA Taxonômico/métodos , Variação Genética , Cariotipagem/métodos , Ortópteros/genética , Filogenia , África Oriental , Animais , Ortópteros/classificação , Especificidade da EspécieRESUMO
Severe acute respiratory syndrome coronavirus 2, the virus that causes coronavirus disease 2019 (COVID-19), has expanded rapidly throughout the world. Thus, it is important to understand how global factors linked with the functioning of the Anthropocene are responsible for the COVID-19 outbreak. We tested hypotheses that the number of COVID-19 cases, number of deaths and growth rate of recorded infections: (1) are positively associated with population density as well as (2) proportion of the human population living in urban areas as a proxies of interpersonal contact rate, (3) age of the population in a given country as an indication of that population's susceptibility to COVID-19; (4) net migration rate and (5) number of tourists as proxies of infection pressure, and negatively associated with (5) gross domestic product which is a proxy of health care quality. Data at the country level were compiled from publicly available databases and analysed with gradient boosting regression trees after controlling for confounding factors (e.g. geographic location). We found a positive association between the number of COVID-19 cases in a given country and gross domestic product, number of tourists, and geographic longitude. The number of deaths was positively associated with gross domestic product, number of tourists in a country, and geographic longitude. The effects of gross domestic product and number of tourists were non-linear, with clear thresholds above which the number of COVID-19 cases and deaths increased rapidly. The growth rate of COVID-19 cases was positively linked to the number of tourists and gross domestic product. The growth rate of COVID-19 cases was negatively associated with the mean age of the population and geographic longitude. Growth was slower in less urbanised countries. This study demonstrates that the characteristics of the human population and high mobility, but not population density, may help explain the global spread of the virus. In addition, geography, possibly via climate, may play a role in the pandemic. The unexpected positive and strong association between gross domestic product and number of cases, deaths, and growth rate suggests that COVID-19 may be a new civilisation disease affecting rich economies.
Assuntos
Betacoronavirus , Infecções por Coronavirus/etiologia , Infecções por Coronavirus/transmissão , Pneumonia Viral/etiologia , Pneumonia Viral/transmissão , Fatores Etários , COVID-19 , Clima , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/virologia , Emigração e Imigração , Produto Interno Bruto , Humanos , Modelos Teóricos , Pandemias , Pneumonia Viral/mortalidade , Pneumonia Viral/virologia , Densidade Demográfica , SARS-CoV-2 , Fatores de Tempo , Viagem , UrbanizaçãoRESUMO
Gonatoxia helleri Hemp, 2016 is one of the most widespread bush-crickets of the genus Gonatoxia Karsch, 1889 in East Africa. This species with seven large chromosomes (2nâ = 7) differs from other representatives of the genus Gonatoxia drastically by its reduced chromosome number, the asymmetrical karyotype including karyomorphs rarely found in tettigoniids, as well as in irregularities in the course of meiosis. To better understand the origin of such an exceptional karyotype, chromosomes of 29 specimens from four populations/localities were studied using classical techniques, such as C-banding, silver impregnation, fluorochrome double staining and fluorescence in situ hybridization (FISH) technique with 18S rDNA and (TTAGG) n telomeric probes. FISH showed many 18S rDNA loci as well as interstitial telomeric sequences, where chromosome morphology varied in these components in terms of quantity and distribution. The 18S rDNA loci coincided with active NORs and C-banding patterns. We suggest that a combination of Robertsonian rearrangements and/or multiple common tandem fusions involving the same chromosomes contributed to the formation of this karyotype/karyomorphs. The results are the first step towards a better understanding of chromosomal reorganization and evolution within the genus Gonatoxia. Low chromosome number, together with the incidence of chromosomal polymorphism that is higher in G. helleri than previously reported in bush-crickets, implies that this species can be a valuable new model for cytogenetic and speciation studies. Our findings suggest that chromosomal translocations lead to diversification and speciation in this species and could be the driving force of adaptive radiation.
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The cytogenetic characteristics of the grasshopper Podisma sapporensis (two races 2n = 23â X0/XX and 2n = 22â neo-XY/neo-XX) were analysed through fluorescence in situ hybridization with rDNA and telomeric DNA probes, C-banding, fluorochrome and silver staining. For the first time, samples from the neighbourhood of a hybrid population (i.e., Mikuni Pass population) were studied. Our results indicated a significant degree of chromosomal differentiation between P. sapporensis races when comparing the number and position of the rDNA sites, as well as the heterochromatin composition and distribution obtained by C-banding and DAPI/CMA3 staining. Telomeric signals were usually detected at the distal and/or subdistal position of the autosomes; however, some chromosome ends lacked signals, probably due to a low number of telomeric repeats. On the other hand, telomeric DNA sequences were found as interstitial telomeric repeats in some autosomes, which can trigger a variety of genome instability. B chromosomes were found in specimens belonging to both main races from nine out of 22 localities. Four types of X chromosomes in the X0/XX race were identified. It was concluded that the physical mapping of rDNA sequences and heterochromatin are useful as additional markers for understanding the phylogeographic patterns of cytogenetic differentiation in P. sapporensis populations.
Assuntos
Cromossomos de Insetos/química , DNA Ribossômico/genética , Especiação Genética , Gafanhotos/genética , Filogenia , Telômero/química , Animais , Bandeamento Cromossômico , Marcadores Genéticos , Instabilidade Genômica , Gafanhotos/classificação , Heterocromatina/química , Hibridização in Situ Fluorescente , Japão , Cariotipagem , Masculino , FilogeografiaRESUMO
Mealybugs (Hemiptera, Coccomorpha: Pseudococcidae) are plant sap-sucking insects which require close association with nutritional microorganisms for their proper development and reproduction. Here, we present the results of histological, ultrastructural, and molecular analyses of symbiotic systems of six mealybugs belonging to the Phenacoccinae subfamily: Phenacoccus aceris, Rhodania porifera, Coccura comari, Mirococcus clarus, Peliococcus calluneti, and Ceroputo pilosellae. Molecular analyses based on bacterial 16S rRNA genes have revealed that all the investigated species of Phenacoccinae are host to only one type of symbiotic bacteria-a large pleomorphic betaproteobacteria-Tremblaya phenacola. In all the species examined, bacteria are localized in the specialized cells of the host-insect termed bacteriocytes and are transovarially transmitted between generations. The mode of transovarial transmission is similar in all of the species investigated. Infection takes place in the neck region of the ovariole, between the tropharium and vitellarium. The co-phylogeny between mealybugs and bacteria Tremblaya has been also analyzed.
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Hemípteros/química , Hemípteros/ultraestrutura , Insetos/química , Insetos/ultraestrutura , AnimaisRESUMO
The random amplified polymorphic DNA (RAPD-PCR) method was used to study the genetic polymorphism of 20 species of the genus Isophya. Each primer amplified a different set of DNA fragments, all oligonucleotides failed to generate any specific diagnostic band that could lead to the identification of Isophya species, and none of the amplified fragments were present in all species. RAPD markers detected a high level of polymorphism in all species. The data were in most cases not congruent with morphological subdivision to the species group and cytotaxonomic studies. The genetic lineages of Isophya seem to be in discordance with relationships proposed by systematists.
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Ortópteros/classificação , Ortópteros/genética , Filogenia , Polimorfismo Genético , Animais , Análise por Conglomerados , Primers do DNA/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Especificidade da EspécieRESUMO
The genus Isophya represents one of the largest orthopteran genera with about 45 species occurring in Europe. All over its range the genus includes groups of sibling species, the recognition of which is hampered by their morphological similarity. In part, some species were grouped according to their morphology: the Isophya straubei-group, the I. amplipennis-group and the I. major-group. Nevertheless, many species have not been studied using new methods. This is particularly true for 15 taxa described from the Balkans, more or less resembling I. modesta, known mostly from old, unsatisfactorily informative descriptions. Chromosomal analysis of 25 species/subspecies of the genus Isophya showed the karyotypic evolution among species. The karyotype of 18 species/subspecies was investigated for the first time. The most remarkable changes in the sex chromosomes were the ancient acrocentric X chromosome inversions in 19 species and an X chromosome/autosome mutual tandem translocation, from which the sex determination system neo-XY originated in I. hemiptera. Karyotype differentiation has been less rapid in autosomes than in sex chromosomes, in this case interspecific autosomal differentiation has involved the distribution and quantity of C-heterochromatin as well as the number of NORs. Cytogenetic analysis revealed some changes reflecting the level of genomic organization, and the results suggest some association of related taxa from biogeographic regions.
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Evolução Biológica , Cromossomos/genética , Ortópteros/anatomia & histologia , Ortópteros/classificação , Ortópteros/genética , Animais , Europa Oriental , Cariotipagem , Especificidade da EspécieRESUMO
Five species belonging to the genus Gampsocleis Fieber, 1852 were analyzed using fluorescence in situ hybridization (FISH) with 18S rDNA and telomeric probes, as well as C-banding, DAPI/CMA3 staining and silver impregnation. The studied species showed two distinct karyotypes, with 2n = 31 (male) and 2n = 23 (male) chromosomes. The drastic reduction in chromosome number observed in the latter case suggests multiple translocations and fusions as the main responsible that occurred during chromosome evolution. Two groups of rDNA distribution were found in Gampsocleis representatives analyzed. Group 1, with a single large rDNA cluster on the medium-sized autosome found in four species, carried in the haploid karyotype. Group 2, represented only by G.abbreviata, was characterized by the presence of two rDNA signals. TTAGG telomeric repeats were found at the ends of chromosome arms as expected. The rDNA clusters coincided with active NORs and GC-rich segments.
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The present study focused on the evolution of the karyotype in four genera of the tribe Pholidopterini: Eupholidoptera Maran, 1953, Parapholidoptera Maran, 1953, Pholidoptera Wesmaël, 1838, Uvarovistia Maran, 1953. Chromosomes were analyzed using fluorescence in situ hybridization (FISH) with 18S rDNA and (TTAGG) n telomeric probes, and classical techniques, such as C-banding, silver impregnation and fluorochrome DAPI/CMA3 staining. Most species retained the ancestral diploid chromosome number 2n = 31 (male) or 32 (female), while some of the taxa, especially a group of species within genus Pholidoptera, evolved a reduced chromosome number 2n = 29. All species show the same sex determination system X0/XX. In some taxa, a pericentric inversion has changed the morphology of the ancestral acrocentric X chromosome to the biarmed X. The rDNA loci coincided with active NORs and C-band/CG-rich segments. A comparison of the location of the single rDNA/NOR in the genus Pholidoptera suggests that reduced chromosome number results from Robertsonian translocation between two pairs of autosomes, one carrying the rDNA/NOR. The results constitute a step towards better understanding of the chromosomal reorganization and evolution within the tribe Phaneropterini and the whole subfamily Tettigoniinae.
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Plant sap-feeding hemipterans harbor obligate symbiotic microorganisms which are responsible for the synthesis of amino acids missing in their diet. In this study, we characterized the obligate symbionts hosted in the body of the xylem-feeding leafhopper Evacanthus interruptus (Cicadellidae: Evacanthinae: Evacanthini) by means of histological, ultrastructural and molecular methods. We observed that E. interruptus is associated with two types of symbiotic microorganisms: bacterium 'Candidatus Sulcia muelleri' (Bacteroidetes) and betaproteobacterium that is closely related to symbionts which reside in two other Cicadellidae representatives: Pagaronia tredecimpunctata (Evacanthinae: Pagaronini) and Hylaius oregonensis (Bathysmatophorinae: Bathysmatophorini). Both symbionts are harbored in their own bacteriocytes which are localized between the body wall and ovaries. In E. interruptus, both Sulcia and betaproteobacterial symbionts are transovarially transmitted from one generation to the next. In the mature female, symbionts leave the bacteriocytes and gather around the posterior pole of the terminal oocytes. Then, they gradually pass through the cytoplasm of follicular cells surrounding the posterior pole of the oocyte and enter the space between them and the oocyte. The bacteria accumulate in the deep depression of the oolemma and form a characteristic 'symbiont ball'. In the light of the results obtained, the phylogenetic relationships within modern Cicadomorpha and some Cicadellidae subfamilies are discussed.