Circadian clocks are timekeeping mechanisms that help organisms anticipate periodic alterations of day and night. These clocks are widespread, and in the case of animals, they rely on genetically related components. At the molecular level, the animal circadian clock consists of several interconnected transcription-translation feedback loops. Although the clock setup is generally conserved, some important differences exist even among various insect groups. Therefore, we decided to identify in silico all major clock components and closely related genes in Hemiptera. Our analyses indicate several lineage-specific alterations of the clock setup in Hemiptera, derived from gene losses observed in the complete gene set identified in the outgroup, Thysanoptera, which thus presents the insect lineage with a complete clock setup. Nilaparvata and Fulgoroidea, in general, lost the (6-4)-photolyase, while all Hemiptera lost FBXL3, and several lineage-specific losses of dCRY and jetlag were identified. Importantly, we identified non-canonical splicing variants of period and m-cry genes, which might provide another regulatory mechanism for clock functioning. Lastly, we performed a detailed reconstruction of Hemiptera's light input pathway genetic repertoire and explored the horizontal gene transfer of cryptochrome-DASH from plant to Bemisia. Altogether, this inventory reveals important trends in clock gene evolution and provides a reference for clock research in Hemiptera, including several lineages of important pest species.
- Klíčová slova
- Circadian clock, Cryptochrome, Evolution, Gene loss, Horizontal gene transfer, Photolyase,
- MeSH
- cirkadiánní hodiny * genetika MeSH
- fylogeneze MeSH
- Hemiptera * genetika fyziologie MeSH
- hmyzí proteiny genetika metabolismus MeSH
- molekulární evoluce * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- hmyzí proteiny MeSH
Cicadidae is one of the most species-rich insect families today. However, compared to the number of extant species, fossil records of Cicadidae are extremely limited. Among singing cicadas, the tribe Platypleurini within the Cicadinae subfamily is notable for its broad geographic distribution, high species diversity, and distinctive features, but no reliable fossil records have been discovered to date. In this study, we report the first fossil record of the Platypleurini from the Eocene Messel Pit: a new genus and species, Eoplatypleura messelensis. This species not only represents one of the earliest known fossil crown-group Cicadidae from the Eurasian continent but also the oldest confirmed record of the subfamily Cicadinae worldwide to date. As the first described fossil singing cicada from the Eocene Messel Pit, this discovery enriches the species diversity of the Messel biota and fills a significant gap in the Eocene cicada fossil record. The discovery of E. messelensis gen. et sp. nov. will serve as a fossil calibration point for future molecular phylogenetic studies and provides new insights into the origins and dispersal patterns of Platypleurini. Based on the analysis of existing records, Cicadidae was once widely distributed in Germany and across Europe during the Cenozoic.
- MeSH
- fylogeneze MeSH
- Hemiptera * fyziologie klasifikace anatomie a histologie MeSH
- vokalizace zvířat * fyziologie MeSH
- zkameněliny * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Německo MeSH
Psyllids, or jumping plant lice (Hemiptera: Sternorrhyncha: Psylloidea), are a group of small phytophagous insects that include some important pests of crops worldwide. Sexual communication of psyllids occurs via vibrations transmitted through host plants, which play an important role in mate recognition and localization. The signals are species-specific and can be used to aid in psyllid taxonomy and pest control. Several hypotheses have been proposed for the mechanism that generates these vibrations, of which stridulation, that is, friction between parts of the forewing and thorax, has received the most attention. We have investigated vibrational communication in the European pear psyllid species Cacopsylla pyrisuga (Foerster, 1848) using laser vibrometry and high-speed video recording, to directly observe the movements associated with signal production. We describe for the first time the basic characteristics of the signals and signal emission of this species. Based on observations and analysis of the video recordings using a point-tracking algorithm, and their comparison with laser vibrometer recordings, we argue that males of C. pyrisuga produce the vibrations primarily by wing buzzing, that is, tremulation that does not involve friction between the wings and thorax. Comparing observed signal properties with previously published data, we predict that wing buzzing is the main mechanism of signal production in all vibrating psyllids.
- Klíčová slova
- Cacopsylla pyrisuga, high‐speed video recording, jumping plant lice, sexual communication, substrate‐borne vibrational signals, vibrational communication,
- MeSH
- audiovizuální záznam MeSH
- Hemiptera * fyziologie MeSH
- komunikace zvířat * MeSH
- křídla zvířecí * fyziologie MeSH
- vibrace * MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Cassava (Manihot esculenta) is among the most important staple crops globally, with an imperative role in supporting the Sustainable Development Goal of 'Zero hunger'. In sub-Saharan Africa, it is cultivated mainly by millions of subsistence farmers who depend directly on it for their socio-economic welfare. However, its yield in some regions has been threatened by several diseases, especially the cassava brown streak disease (CBSD). Changes in climatic conditions enhance the risk of the disease spreading to other planting regions. Here, we characterise the current and future distribution of cassava, CBSD and whitefly Bemisia tabaci species complex in Africa, using an ensemble of four species distribution models (SDMs): boosted regression trees, maximum entropy, generalised additive model, and multivariate adaptive regression splines, together with 28 environmental covariates. We collected 1,422 and 1,169 occurrence records for cassava and Bemisia tabaci species complex from the Global Biodiversity Information Facility and 750 CBSD occurrence records from published literature and systematic surveys in East Africa. Our results identified isothermality as having the highest contribution to the current distribution of cassava, while elevation was the top predictor of the current distribution of Bemisia tabaci species complex. Cassava harvested area and precipitation of the driest month contributed the most to explain the current distribution of CBSD outbreaks. The geographic distributions of these target species are also expected to shift under climate projection scenarios for two mid-century periods (2041-2060 and 2061-2080). Our results indicate that major cassava producers, like Cameron, Ivory Coast, Ghana, and Nigeria, are at greater risk of invasion of CBSD. These results highlight the need for firmer agricultural management and climate-change mitigation actions in Africa to combat new outbreaks and to contain the spread of CBSD.
- Klíčová slova
- Bemisia tabaci, Cassava, Cassava brown streak disease, Climate change, Food security, Zero hunger,
- MeSH
- Hemiptera * fyziologie MeSH
- maniok * parazitologie MeSH
- nemoci rostlin * parazitologie statistika a číselné údaje MeSH
- zemědělské plodiny růst a vývoj parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Afrika epidemiologie MeSH
Cicadas and many of their relatives (Hemiptera: Cicadomorpha) generate vibroacoustic signals using tymbal organs located on their first two abdominal segments. Although tymbals are well-studied in Cicadidae, their systematic distribution in other Cicadomorpha and their possible homologies to the vibroacoustic mechanisms of other Hemiptera have been debated for more than a century. In the present study, we re-examine the morphology of the musculoskeletal system of cicadomorphan vibroacoustic organs, and we document their systematic distribution in 78 species drawn from across the phylogeny of Cicadomorpha. We also compare their morphology to the recently-described snapping organ of planthoppers (Fulgoromorpha). Based on the structure and innervation of the metathoracic and abdominal musculoskeletal system, we find that several key elements of cicadomorphan vibroacoustic organs that have previously been assigned to the first abdominal segment in fact belong to the second. We find that tymbal organs are nearly ubiquitous in Cicadomorpha, and conclude based on their phylogenetic distribution, that they are likely to be synapomorphic. The unusual tymbal-like organs of the Deltocephalinae and Typhlocybinae, represent derived modifications. Finally, we propose a standardised terminology for sternal components of the cicadomorphan vibrational organs, which can be used in future taxonomic descriptions.
- Klíčová slova
- Auchenorrhyncha, Bioacoustics, Biotremology, Snapping organ, Tymbal, Tymbalia,
- MeSH
- biologická evoluce MeSH
- fylogeneze MeSH
- Hemiptera anatomie a histologie fyziologie MeSH
- vokalizace zvířat * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The smallest reported bacterial genome belongs to Tremblaya princeps, a symbiont of Planococcus citri mealybugs (PCIT). Tremblaya PCIT not only has a 139 kb genome, but possesses its own bacterial endosymbiont, Moranella endobia. Genome and transcriptome sequencing, including genome sequencing from a Tremblaya lineage lacking intracellular bacteria, reveals that the extreme genomic degeneracy of Tremblaya PCIT likely resulted from acquiring Moranella as an endosymbiont. In addition, at least 22 expressed horizontally transferred genes from multiple diverse bacteria to the mealybug genome likely complement missing symbiont genes. However, none of these horizontally transferred genes are from Tremblaya, showing that genome reduction in this symbiont has not been enabled by gene transfer to the host nucleus. Our results thus indicate that the functioning of this three-way symbiosis is dependent on genes from at least six lineages of organisms and reveal a path to intimate endosymbiosis distinct from that followed by organelles.
- MeSH
- aminokyseliny biosyntéza MeSH
- Bacteria klasifikace genetika MeSH
- Betaproteobacteria genetika MeSH
- fylogeneze MeSH
- Hemiptera genetika mikrobiologie fyziologie MeSH
- molekulární sekvence - údaje MeSH
- přenos genů horizontální * MeSH
- stanovení celkové genové exprese MeSH
- symbióza * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- Názvy látek
- aminokyseliny MeSH
The most representative sample of molecular data, especially 16S and 12S rDNAs, is used to study the phylogeny and evolution of 57 species of three tribes, Rhodniini, Linshcosteini, and Triatomini, of the subfamily Triatominae. For the first time both New World and Old World species are brought together in a single phylogenetic analysis. Maximum-parsimony and distance estimation place both the Asiatic representatives, Linshcosteus and Triatoma rubrofasciata, as sister groups. The Linshcosteus-T. rubrofasciata clade nests firmly within Triatomini, in most analyses branching as a basalmost lineage, thus supporting a monophyletic origin of Triatominae. A paraphyly of "Triatoma" with respect to Linshcosteus, Dipetalogaster, Eratyrus, and Panstrongylus and the paraphyly of "Rhodnius" with respect to Psammolestes is observed in most of the analyses. Reinterpretation of triatomine biogeography points to the origin of Triatominae in northern areas of South America, in Central America, or in the southern region of North America. A few taxonomic changes are proposed: (1) reinclusion of Linshcosteus in Triatomini, (2) inclusion of Psammolestes in Rhodnius, (3) elevation of the "T. flavida complex" to the full genus Nesotriatoma (including N. flavida, N. bruneri, and N. obscura), (4) inclusion of the "T. spinolai complex" in Mepraia (including M. spinolai, M. gajardoi, M. eratyrusiformis, and M. breyeri), and (5) inclusion of "T." dimidiata in Meccus (M. dimidiatus).
- MeSH
- fylogeneze * MeSH
- Hemiptera fyziologie MeSH
- molekulární evoluce MeSH
- ribozomální DNA MeSH
- RNA ribozomální 16S MeSH
- Triatominae fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Amerika MeSH
- Asie MeSH
- Názvy látek
- ribozomální DNA MeSH
- RNA ribozomální 16S MeSH