RESUMO
The Mormon cricket, Anabrus simplex, is a flightless katydid, one of the major devastating rangeland pests in several states of the western United States. During the past few years, their sudden and periodic outbreaks into massive migratory bands caused significant economic losses to the rangeland forage and agricultural crops, particularly grain crops. Current population management methods rely heavily on broad-spectrum chemical insecticides, which could be toxic to nontargets, and even the targeted species might develop resistance in the long run. Therefore, we assessed the potential of RNA interference (RNAi)-based alternative management strategies that could supplement the current methods. In insects, RNAi efficiency varies with the method of double-stranded RNA (dsRNA) delivery. We tested 2 different methods of dsRNA delivery: injection and oral feeding of dsRNA. The results showed that Mormon crickets are sensitive to injection of dsRNA in a dose-dependent manner, but refractory to the oral feeding of dsRNA. Further, we confirmed the high nuclease activity in the insect midgut. In order to protect the dsRNA from the dsRNase activity and facilitate its uptake in the midgut, we encapsulated dsRNA inside poly lactic-co-glycolic acid (PLGA) nanoparticles and studied its release kinetics and RNAi efficiency by oral feeding. The release kinetics clearly suggested that the PLGA nanoparticle permeates from the insect digestive system to the hemolymph; however, it failed to induce an efficient RNAi response of the targeted genes. In conclusion, our findings suggest the different responses to dsRNA delivery methods in Mormon crickets, and further investigations involving dsRNA stability and its uptake mechanism are required to use RNAi as an alternative Mormon cricket population management strategy.
Assuntos
Gryllidae , Animais , Gryllidae/genética , RNA de Cadeia Dupla , Insetos/genética , Interferência de RNARESUMO
Background and Objective: The tongue mucosa often changes due to various local and systemic diseases or conditions. This study aimed to investigate whether deep learning can help detect abnormal regions on the dorsal tongue surface in patients and healthy adults. Materials and Methods: The study collected 175 clinical photographic images of the dorsal tongue surface, which were divided into 7782 cropped images classified into normal, abnormal, and non-tongue regions and trained using the VGG16 deep learning model. The 80 photographic images of the entire dorsal tongue surface were used for the segmentation of abnormal regions using point mapping segmentation. Results: The F1-scores of the abnormal and normal classes were 0.960 (precision: 0.935, recall: 0.986) and 0.968 (precision: 0.987, recall: 0.950), respectively, in the prediction of the VGG16 model. As a result of evaluation using point mapping segmentation, the average F1-scores were 0.727 (precision: 0.717, recall: 0.737) and 0.645 (precision: 0.650, recall: 0.641), the average intersection of union was 0.695 and 0.590, and the average precision was 0.940 and 0.890, respectively, for abnormal and normal classes. Conclusions: The deep learning algorithm used in this study can accurately determine abnormal areas on the dorsal tongue surface, which can assist in diagnosing specific diseases or conditions of the tongue mucosa.
Assuntos
Aprendizado Profundo , Adulto , Humanos , Algoritmos , Rememoração Mental , Mucosa BucalRESUMO
Ensiferan orthopterans offer a key study system for acoustic communication and the process of insect hearing. Cyphoderris monstrosa (Hagloidea) belongs to a relict ensiferan family and is often used for evolutionary comparisons between bushcrickets (Tettigoniidae) and their ancestors. Understanding how this species processes sound is therefore vital to reconstructing the evolutionary history of ensiferan hearing. Previous investigations have found a mismatch in the ear of this species, whereby neurophysiological and tympanal tuning does not match the conspecific communication frequency. However, the role of the whole tympanum in signal reception remains unknown. Using laser Doppler vibrometry, we show that the tympana are tonotopic, with higher frequencies being received more distally. The tympana use two key modalities to mechanically separate sounds into two auditory receptor populations. Frequencies below approximately 8 kHz generate a basic resonant mode in the proximal end of the tympanum, whereas frequencies above approximately 8 kHz generate travelling waves in the distal region. Micro-CT imaging of the ear and the presented data suggest that this tonotopy of the tympana drive the tonotopic mechanotransduction of the crista acustica (CA). This mechanism represents a functional intermediate between simple tuned tympana and the complex tonotopy of the bushcricket CA.
Assuntos
Orelha Interna , Gryllidae , Animais , Orelha Média , Gryllidae/fisiologia , Mecanotransdução Celular , VibraçãoRESUMO
Locusts exhibit an extreme form of phenotypic plasticity and can exist as two alternative phenotypes, known as solitarious and gregarious phases. These phases, which can transform from one to another depending on local population density, show distinctly different behavioural characteristics. The proximate mechanisms of behavioural phase polyphenism have been well studied in the desert locust Schistocerca gregaria and the migratory locust Locusta migratoria, and what is known in these species is often treated as a general feature of locusts. However, this approach might be flawed, given that there are approximately 20 locust species that have independently evolved phase polyphenism. Using the Central American locust Schistocerca piceifrons as a study system, we characterised the time course of behavioural phase change using standard locust behavioural assays, using both a logistic regression-based model and analyses of separate behavioural variables. We found that for nymphs of S. piceifrons, solitarisation was a relatively fast, two-step process, but that gregarisation was a much slower process. Additionally, the density of the gregarisation treatment seemed to have no effect on the rate of phase change. These data are at odds with what we know about the time course of behavioural phase change in S. gregaria, suggesting that the mechanisms of locust phase polyphenism in these two species are different and may not be phylogenetically constrained. Our study represents the most in-depth study of behavioural gregarisation and solitarisation in locusts to date.
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Gafanhotos , Animais , Humanos , População da América CentralRESUMO
(1) Background: Insects, which serve as model systems for many disciplines with their unique advantages, have not been extensively studied in gait research because of the lack of appropriate tools and insect models to properly study the insect gaits. (2) Methods: In this study, we present a gait analysis of grasshoppers with a closed-loop custom-designed motorized insect treadmill with an optical recording system for quantitative gait analysis. We used the eastern lubber grasshopper, a flightless and large-bodied species, as our insect model. Gait kinematics were recorded and analyzed by making three grasshoppers walk on the treadmill with various speeds from 0.1 to 1.5 m/s. (3) Results: Stance duty factor was measured as 70-95% and decreased as walking speed increased. As the walking speed increased, the number of contact legs decreased, and diagonal arrangement of contact was observed at walking speed of 1.1 cm/s. (4) Conclusions: This pilot study of gait analysis of grasshoppers using the custom-designed motorized insect treadmill with the optical recording system demonstrates the feasibility of quantitative, repeatable, and real-time insect gait analysis.
Assuntos
Análise da Marcha , Gafanhotos , Animais , Fenômenos Biomecânicos , Teste de Esforço , Marcha , Projetos Piloto , CaminhadaRESUMO
Voltage-gated sodium (NaV) channels, encoded by the gene para, play a critical role in the rapid processing and propagation of visual information related to collision avoidance behaviors. We investigated their localization by immunostaining the optic lobes and central brain of the grasshopper Schistocerca americana and the vinegar fly Drosophila melanogaster with an antibody that recognizes the channel peptide domain responsible for fast inactivation gating. NaV channels were detected at high density at all stages of development. In the optic lobe, they revealed stereotypically repeating fascicles consistent with the regular structure of the eye. In the central brain, major axonal tracts were strongly labeled, particularly in the grasshopper olfactory system. We used the NaV channel sequence of Drosophila to identify an ortholog in the transcriptome of Schistocerca. The grasshopper, vinegar fly, and human NaV channels exhibit a high degree of conservation at gating and ion selectivity domains. Comparison with three species evolutionarily close to Schistocerca identified splice variants of Para and their relation to those of Drosophila. The anatomical distribution of NaV channels molecularly analogous to those of humans in grasshoppers and vinegar flies provides a substrate for rapid signal propagation and visual processing in the context of visually-guided collision avoidance.
Assuntos
Encéfalo/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Gafanhotos/metabolismo , Lobo Óptico de Animais não Mamíferos/patologia , Canais de Sódio/metabolismo , Visão Ocular , Animais , Animais Geneticamente Modificados , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Evolução Molecular , Gafanhotos/genética , Humanos , Ativação do Canal Iônico , Estimulação Luminosa , Canais de Sódio/genética , Especificidade da Espécie , Percepção VisualRESUMO
Eugregarines are understudied apicomplexan parasites of invertebrates inhabiting marine, freshwater, and terrestrial environments. Most currently known terrestrial eugregarines have been described parasitizing the gut from less than 1% of total insect diversity, with a high likelihood that the remaining insect species are infected. Eugregarine diversity in orthopterans (grasshoppers, locusts, katydids, and crickets) is still little known. We carried out a survey of the eugregarines parasitizing the Mexican lubber grasshopper, Taeniopoda centurio, an endemic species to the northwest of Mexico. We described two new eugregarine species from the gut of the host: Amoebogregarina taeniopoda n. sp. and Quadruspinospora mexicana n. sp. Both species are morphologically dissimilar in their life-cycle stages. Our SSU rDNA phylogenetic analysis showed that both species are phylogenetically distant to each other, even though they parasitize the same host. Amoebogregarina taeniopoda n. sp. clustered within the clade Gregarinoidea, being closely related to Amoebogregarina nigra from the grasshopper Melanoplus differentialis. Quadruspinospora mexicana n. sp. clustered within the clade Actinocephaloidea and grouped with Prismatospora evansi, a parasite from dragonfly naiads. Amoebogregarina taeniopoda n. sp. and Q. mexicana n. sp. represent the first record of eugregarines found to infect a species of the family Romaleidae.
Assuntos
Apicomplexa/classificação , Apicomplexa/citologia , Gafanhotos/parasitologia , Interações Hospedeiro-Parasita , Filogenia , Animais , Apicomplexa/ultraestrutura , DNA de Protozoário/análise , DNA Ribossômico/análise , México , Microscopia , Microscopia Eletrônica de Varredura , Análise de Sequência de DNARESUMO
The gaudy grasshopper family Pyrgomorphidae (Orthoptera: Caelifera) shows a peculiar geographical distribution. Of the 487 described species, less than 10% of the diversity is found in the New World, while the rest occur throughout Africa, Asia, and Australia. Only 41 species belonging to four tribes are found in Central and South America and Dominican Republic, and the phylogenetic positions of these taxa within the large phylogeny of Pyrgomorphidae and the relationships among them have never been investigated. Regarding the biogeography, three different hypotheses about the origin of the New World Pyrgomorphidae have been proposed, but these have not been empirically tested. In this study, we present the first molecular phylogeny of Pyrgomorphidae that includes the members of all four New World tribes and representative genera from the Old World based on entire mitochondrial genome and four nuclear genes to investigate the biogeography of this fascinating lineage. Our results recover Pyrgomorphidae as monophyletic and the New World Pyrgomorphidae as a paraphyletic group comprising three clades, consisting of: (1) The Caribbean Jaraguaâ¯+â¯the South American Algete; (2) The Mexican and Central American Sphenariumâ¯+â¯Prosphena; and (3) The Mexican lineages Ichthiacridiniâ¯+â¯Ichthyotettigini. The divergence time estimation analysis suggested that the Pyrgomorphidae diverged from its relatives in the Early Cretaceous (139-104â¯mya). The biogeographic analysis using BioGeoBEARS showed that after diversifying in the Old World, the first New World Pyrgomorphidae clade (Algeteâ¯+â¯Jaragua) diverged 96â¯mya (Late Cretaceous, Cenomanian) and that their current distribution in the New World is explained by two possible events, a transatlantic colonization from Africa to Northern South America or a vicariance event between these two landmasses, followed by a subsequent dispersal to the Caribbean. The second wave of colonization occurred about 69â¯mya towards the end of the Late Cretaceous (Maastrichtian) with dispersal from Africa to South America and then to North America with a subsequent diversification in Mexico including Baja California.
Assuntos
Gafanhotos/genética , Animais , Núcleo Celular/genética , Genoma Mitocondrial , Gafanhotos/classificação , Funções Verossimilhança , Filogenia , Filogeografia , Fatores de TempoRESUMO
The surface characteristics and osteoconductivity were evaluated for the micro/nanoporous surfaces of titanium (Ti) alloys prepared by micro-arc oxidation (MAO) and hydrothermal treatment (HT) of binary Ti-5 wt% A alloys (A = Au, Mn, Nb, and Pd). Surface properties were analyzed using X-ray diffractometry, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The osteoconductivity was evaluated by measuring the total protein, ALPase activity, and osteocalcin production. The surface morphologies of MAO/HT specimens mainly affected on their osteoconductivity. Total proteins on Ti alloys (MAO/HT) were slightly lower than that on commercially pure Ti (MAO/HT) after incubation of MG-63 osteoblast-like cells for 14 days. However, better ALPase activity and osteocalcin production were observed on MAO/HT-treated Ti5Mn, Ti5Nb, and Ti5Pd than that on cp-Ti (MAO/HT) after 14 days. Especially, Ti5Mn (MAO/HT) showed a significant increase of ALPase activity due to its well grown micro/nano structure. Meanwhile, very small nanorods on Ti5Au (MAO/HT) affected negatively to ALPase activity and osteocalcin production.
RESUMO
Orthoptera is the most diverse order among the polyneopteran groups and includes familiar insects, such as grasshoppers, crickets, katydids, and their kin. Due to a long history of conflicting classification schemes based on different interpretations of morphological characters, the phylogenetic relationships within Orthoptera are poorly understood and its higher classification has remained unstable. In this study, we establish a robust phylogeny of Orthoptera including 36 of 40 families representing all 15 currently recognized superfamilies and based on complete mitochondrial genomes and four nuclear loci, in order to test previous phylogenetic hypotheses and to provide a framework for a natural classification and a reference for studying the pattern of divergence and diversification. We find strong support for monophyletic suborders (Ensifera and Caelifera) as well as major superfamilies. Our results corroborate most of the higher-level relationships previously proposed for Caelifera, but suggest some novel relationships for Ensifera. Using fossil calibrations, we provide divergence time estimates for major orthopteran lineages and show that the current diversity has been shaped by dynamic shifts of diversification rates at different geological times across different lineages. We also show that mitochondrial tRNA gene orders have been relatively stable throughout the evolutionary history of Orthoptera, but a major tRNA gene rearrangement occurred in the common ancestor of Tetrigoidea and Acridomorpha, thereby representing a robust molecular synapomorphy, which has persisted for 250 Myr.
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Management practices can disturb ecological communities in grazing lands, which represent one-quarter of land surface. But three knowledge gaps exist regarding disturbances: disturbances potentially interact but are most often studied singly; experiments with multiple ecosystems as treatment units are rare; and relatively new metrics of phylogenetic community structure have not been widely applied. We addressed all three of these needs with a factorial experiment; 40 seasonal wetlands embedded in a Florida ranch were treated with pasture intensification, cattle exclosure, and prescribed fire. Treatment responses were evaluated through four years for aquatic beetle (Coleoptera: Adephaga) assemblages using classic ecological metrics (species richness, diversity) and phylogenetic community structure (PCS) metrics. Adephagan assemblages consisted of 23 genera representing three families in a well-resolved phylogeny. Prescribed fire significantly reduced diversity one year post-fire, followed by a delayed pasture X fire interaction. Cattle exclosure significantly reduced one PCS metric after one year and a delayed pasture x fence x fire interaction was detected with another PCs metric. Overall, effects of long-term pasture intensification were modified by cattle exclosure and prescribed fire. Also, PCS metrics revealed effects otherwise undetected by classic ecological metrics. Management strategies (e.g., "flash grazing," prescribed fires) in seasonal wetlands may successfully balance economic gains from high forage quality with ecological benefits of high wetland diversity in otherwise simplified grazing lands. Effects are likely taxon specific; multiple taxa should be similarly evaluated.
Assuntos
Besouros/genética , Besouros/fisiologia , Filogenia , Áreas Alagadas , Agroquímicos , Animais , Bovinos , Fatores de TempoRESUMO
The objective of this study is to fabricate bone-like apatite (BLAp) powder using the modified simulated body fluid (SBF). The SBF2X and SBF4X groups were prepared by increasing the concentration of inorganic ions by two and four times, respectively, to that of the standard SBF. The mSBF4X group was prepared by particularly increasing the concentrations of calcium and phosphate ions in SBF. Bovine serum albumin (BSA) was added for SBF2X-BSA, SBF4X-BSA, and mSBF4X-BSA groups. BLAp powders were precipitated in these SBFs while being kept at 60 °C. Micro-morphology of BLAp powders showed tens of micrometers-sized rounded clusters which composed with sheet-like nano crystallites. The radius of BLAp clusters were decreased by increasing the concentration of inorganic ions and by incorporating the BSA. The hydroxyapatite crystalline structure was dominant for all sample groups. Further, octacalcium phosphate structure was detected in the mSBF4X group. However, these peaks were decreased in mSBF4X-BSA. FT-IR spectra demonstrated that BSA was co-precipitated in BLAp crystallites, and the amount of BSA was higher in the mSBF4X-BSA group than in the SBF4X-BSA group.
Assuntos
Apatitas/química , Materiais Biomiméticos/química , Líquidos Corporais/química , Substitutos Ósseos/química , Nanopartículas/química , Nanopartículas/ultraestrutura , Teste de Materiais/métodos , Tamanho da Partícula , Pós , Soroalbumina Bovina , Propriedades de SuperfícieRESUMO
Surface characteristics and osteoblast cell functions were investigated for the nano-structured oxide layer on commercially pure titanium (CP-Ti) fabricated using microarc oxidation (MAO) and hydrothermal treatment (HT) methods. Ti-MAO-135HT, Ti-MAO-150HT, and Ti-MAO-175HT groups were fabricated by hydrothermally treating the MAO-treated specimens (Ti-MAO) in phosphorus-containing alkaline solution at temperatures of 135, 150, or 175 °C, respectively. After hydrothermal treatment, a nanosheet-shaped morphology, nano-needles and nanorods were observed on the porous surface of the Ti-MAO-135HT, Ti-MAO-150HT and Ti-MAO-175HT groups, respectively. The roughness was not significantly different for all groups. However the contact angle decreased dramatically as the hydrothermal temperature increased. The osteoblastic cell adhesion and viability of the Ti-MAO-150HT and Ti-MAO-175HT groups were significantly lower compared to those of the Ti-MAO group. This study showed that nano-topology formed on micro porous oxide layer was more important than hydrophilicity in its effect upon initial osteoblastic cell functions.
Assuntos
Adesão Celular , Nanoestruturas , Osteoblastos/citologia , Titânio/química , Humanos , Microscopia Eletrônica de Varredura , Difração de Raios XRESUMO
Liladownsia fraile gen. nov. sp. nov. Fontana, Mariño-Pérez, Woller & Song (Lila Downs' friar grasshopper) of the tribe Dactylotini (Orthoptera: Acrididae: Melanoplinae) is described from the pine-oak forest of the Sierra Madre del Sur Mountain Range in Oaxaca, Mexico. Taxonomic placement of this new genus is justified based on morphological characters as well as a molecular phylogeny. Information about the probable host plant, phenology, and known localities is also presented. We also present an updated molecular phylogeny of Melanoplinae, which includes representatives of five of the seven recognized tribes. The monophyly of the subfamily and the included tribes is tested and we find Dactylotini to be paraphyletic because of the placement of Hesperotettix Scudder, 1876. We also recover strong close relationships between the new genus and Perixerus Gerstaecker, 1873 and Dactylotum Charpentier, 1845.
Assuntos
Gafanhotos/classificação , Gafanhotos/fisiologia , Filogenia , Animais , Demografia , Feminino , Gafanhotos/genética , Masculino , México , Especificidade da EspécieRESUMO
Cave crickets (Rhaphidophoridae) are insects of an ancient and wingless lineage within Orthoptera that are distributed worldwide except in Antarctica, and each subfamily has a high level of endemicity. Here, we show the comprehensive phylogeny of cave crickets using multi-gene datasets from mitochondrial and nuclear loci, including all extant subfamilies for the first time. We reveal phylogenetic relationships between subfamilies, including the sister relationship between Anoplophilinae and Gammarotettiginae, based on which we suggest new synapomorphies. Through biogeographic analyses based on divergence time estimations and ancestral range reconstruction, we propose novel hypotheses regarding the biogeographic history of cave crickets. We suggest that Gammarotettiginae in California originated from the Asian lineage when Asia and the Americas were connected by the Bering land bridge, and the opening of the western interior seaway affected the division of Ceuthophilinae from Tropidischiinae in North America. We estimate that Rhaphidophoridae originated at 138 Mya throughout Pangea. We further hypothesize that the loss of wings in Rhaphidophoridae could be the result of their adaptation to low temperatures in the Mesozoic era.
Assuntos
Ortópteros , Animais , Filogenia , Ásia , América do Norte , Regiões AntárticasRESUMO
In many animal species, larger body size is positively correlated with male mating success and female fecundity. However, in the case of insects, in high seasonality environments, natural selection favors a faster maturation that decreases the risk of pre-reproductive death. However, this advantageous adaptation comes at a tradeoff, resulting in a reduction in body size. Maturation time is influenced by environmental factors, such as temperature, season length, and food availability during the rains. The geographic variation in these parameters provides an opportunity to study their impact on the adaptive evolution of body size in Pyrgomorphidae grasshoppers. These grasshoppers exhibit remarkable variation in body size and wing development and can be found in diverse plant communities across Africa, Asia, Australia, and tropical America. In this study, we utilized a phylogenetic approach to examine the evolution of body size, considering climatic factors, and the influence of sexual selection on size differences between males and females. We found a positive correlation between mean annual temperature and sexual size dimorphism (SSD). Remarkably, species exhibiting a strong bias toward larger females were found to be adapted to regions with higher temperatures. In the Pyrgomorphidae family, an intermediate body size was identified as the ancestral trait. Additionally, winged male and female grasshoppers were observed to be larger than their wingless counterparts. Despite the potential conflicting pressures on body size in males and females, these grasshoppers adhere to Rench's Rule, suggesting that sexual selection on males' body size may explain the evolution of SSD.
RESUMO
The phylogenetic relationships of Tettigoniidae (katydids and bush-crickets) were inferred using molecular sequence data. Six genes (18S rDNA, 28S rDNA, Cytochrome Oxidase II, Histone 3, Tubulin Alpha I, and Wingless) were sequenced for 135 ingroup taxa representing 16 of the 19 extant katydid subfamilies. Five subfamilies (Tettigoniinae, Pseudophyllinae, Mecopodinae, Meconematinae, and Listroscelidinae) were found to be paraphyletic under various tree reconstruction methods (Maximum Likelihood, Bayesisan Inference and Maximum Parsimony). Seven subfamilies - Conocephalinae, Hetrodinae, Hexacentrinae, Saginae, Phaneropterinae, Phyllophorinae, and Lipotactinae - were each recovered as well-supported monophyletic groups. We mapped the small and exposed thoracic auditory spiracle (a defining character of the subfamily Pseudophyllinae) and found it to be homoplasious. We also found the leaf-like wings of katydids have been derived independently in at least six lineages.
Assuntos
Evolução Biológica , Ortópteros/classificação , Filogenia , Asas de Animais/anatomia & histologia , Animais , Teorema de Bayes , Núcleo Celular/genética , DNA Mitocondrial/genética , Marcadores Genéticos , Funções Verossimilhança , Modelos Genéticos , Ortópteros/anatomia & histologia , Ortópteros/genética , Análise de Sequência de DNARESUMO
One of the main challenges in analyzing multi-locus phylogenomic data is to find an optimal data partitioning strategy to account for variable evolutionary histories of different loci for any given dataset. Although a number of studies have addressed the issue of data partitioning in a Bayesian phylogenetic framework, such studies in a maximum likelihood framework are comparatively lacking. Furthermore, a rigorous statistical exploration of possible data partitioning schemes has not been applied to mitochondrial genome (mtgenome) data, which provide a complex, but manageable platform for addressing various challenges in analyzing phylogenomic data. In this study, we investigate the issue of data partitioning in the maximum likelihood framework in the context of the mitochondrial phylogenomics of an orthopteran superfamily Acridoidea (Orthoptera: Caelifera). The present study analyzes 34 terminals representing all 8 superfamilies within Caelifera, which includes newly sequenced partial or complete mtgenomes for 11 families. Using a new partition-selection method implemented in the software PartitionFinder, we compare a large number of data partitioning schemes in an attempt to identify the most effective method of analyzing the mtgenome data. We find that the best-fit partitioning scheme selected by PartitionFinder is superior to any a priori schemes commonly utilized in mitochondrial phylogenomics. We also show that over-partitioning is often detrimental to phylogenetic reconstruction. A comparative analysis of mtgenome structures finds that the tRNA gene rearrangement between cytochrome c oxidase subunit II and ATP synthase protein 8 does not occur in the most basal caeliferan lineage Tridactyloidea, suggesting that this gene rearrangement must have evolved at least in the common ancestor of Tetrigoidea and Acridomorpha. We find that mtgenome data contain sufficient phylogenetic information to broadly resolve the relationships across Acridomorpha and Acridoidea.
Assuntos
DNA Mitocondrial/genética , Evolução Molecular , Ortópteros , Filogenia , Algoritmos , Animais , Teorema de Bayes , Genoma Mitocondrial , Ortópteros/classificação , Ortópteros/genética , Análise de Sequência de DNA , SoftwareRESUMO
Inadvertent coamplification of nuclear mitochondrial pseudogenes (numts) is a serious problem in mitochondrial systematics, but numts can also be a valuable source of information because they represent ancient forms of mtDNA. We present a conceptual framework of numt accumulation, which states that in a given species there can be two types of numts, synaponumts and autaponumts, resulting from integration occurring respectively before and after a speciation event. In a given clade, a species that diverged early can only have its own autaponumts as well as synaponumts that were already present in the genome of the last common ancestor. A species that diverged more recently may, however, have many different synaponumts integrated at each different divergence as well as its own autaponumts. Therefore it is possible to decipher the evolutionary history of a species based on the phylogenetic distribution of numts in a simultaneous analysis of numts and extant mtDNA. In this study, we test this idea empirically in the context of addressing a controversial question regarding the biogeography of the grasshopper genus Schistocerca Stål (Orthoptera: Acrididae), based on numts of the cytochrome c oxidase subunit I (COI) gene. We find that our empirical data can be explained adequately by our conceptual framework, and that the phylogenetic distribution of COI numts reveals intricate evolutionary histories about past speciation events that are otherwise difficult to detect using conventional markers. Our study strongly favours the Old World origin of the desert locust, Schistocerca gregaria and the New World Schistocerca species are descendants from an ancestral gregaria-like species that colonized the New World via westward transatlantic flight. However, the phylogenetic distribution of S. gregaria numts raises a distinct possibility that there might have been multiple founding events from Africa to America to give rise to the present-day diversity of the genus. This is a case study for a creative use of numts as molecular fossils, and we demonstrate that numts provide an interesting and powerful phylogenetic signal, much more than what extant mtDNA or nuclear gene sequences might be able to provide.
RESUMO
Conventional methods for improving the hydrophobicity of polypropylene (PP) membranes to prevent wetting phenomena require complex pretreatment procedures in order to activate the surface for enabling the reaction with fluorosilane (FS)-based materials. This study successfully prepared PP membrane contactors with enhanced hydrophobicity through a simple single-step dip-coating method using perfluoroether-grafted silanes for CO2 capture. The FS coating layer on the PP membrane surface was confirmed through ATR-FTIR spectroscopy, XPS, FE-SEM, and EDS. Furthermore, the evaluation of the CO2 absorption performance and long-term stability of the FS-coated PP membrane according to the variation of the gas flow rate (50, 100, 200, 400, and 800 mL/min) confirmed the superior chemical stability and durability of our membranes to those of previously reported hydrophobic membranes. The as-prepared FS-coated PP membrane expands the application scope of gas-liquid membrane contactors for CO2 capture from the flue gas of coal-fired power plants.