Eriophyoid mites represent a hyperdiverse, phytophagous lineage with an unclear phylogenetic position. These mites have succeeded in colonizing nearly every seed plant species, and this evolutionary ...success was in part due to the mites' ability to induce galls in plants. A gall is a unique niche that provides the inducer of this modification with vital resources. The exact mechanism of gall formation is still not understood, even as to whether it is endogenic (mites directly cause galls) or exogenic (symbiotic microorganisms are involved). Here we (i) investigate the phylogenetic affinities of eriophyoids and (ii) use comparative metagenomics to test the hypothesis that the endosymbionts of eriophyoid mites are involved in gall formation. Our phylogenomic analysis robustly inferred eriophyoids as closely related to Nematalycidae, a group of deep-soil mites belonging to Endeostigmata. Our comparative metagenomics, fluorescence in situ hybridization, and electron microscopy experiments identified two candidate endosymbiotic bacteria shared across samples, however, it is unlikely that they are gall inducers (morphotype1: novel Wolbachia, morphotype2: possibly Agrobacterium tumefaciens). We also detected an array of plant pathogens associated with galls that may be vectored by the mites, and we determined a mite pathogenic virus (Betabaculovirus) that could be tested for using in biocontrol of agricultural pest mites.
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•Phylogeny inferred for Acariform mites, the largest chelicerate lineage.•Relationships of the four-legged mites (Eriophyoidea) are analyzed.•Total evidence tree (6 genes): it is ...sister to family Nematalycidae (Endeostigmata).•Nuclear protein-coding genes (3 genes): it is sister to Eupodina (Trombidiformes).•This result is analyzed using different phylogenetically explicit approaches.
Eriophyoid, or four-legged mites, represent a large and ancient radiation of exclusively phytophagous organisms known from the Triassic (230 Mya). Hypothesizing phylogenetic relatedness of Eriophyoidea among mites is a major challenge due to the absence of unambiguous morphological synapomorphies, resulting in ten published hypotheses placing eriophyoids in various places in the acariform tree of life. Here we test the evolutionary relationships of eriophyoids using six genes and a representative taxonomic sampling of acariform mites. The total evidence analysis places eriophyoids as the sister group of the deep soil-dwelling, vermiform family Nematalycidae (Endeostigmata). This arrangement was supported by the rDNA and CO1 partitions. In contrast, the nuclear protein partition (genes EF1-α, SRP54, HSP70) suggests that Eriophyoidea is sister to a lineage including Tydeidae, Ereynetidae, and Eupodidae (Eupodina: Trombidiformes). On both of these alternative topologies, eriophyoids appear as a long branch, probably involving the loss of basal diversity in early evolution. We analyze this result by using phylogenetically explicit hypothesis testing, investigating the phylogenetic signal from individual genes and rDNA stem and loop regions, and removing long branches and rogue taxa. Regardless of the two alternative placements, (i) the cheliceral morphology of eriophyoids, one of the traits deemed phylogenetically important, was likely derived directly from the plesiomorphic acariform chelicerae rather than from the modified chelicerae of some trombidiform lineages with a reduced fixed digit; and (ii) two potential synapomorphies of Eriophyoidea+Raphignathina (Trombidiformes) related to the reduction of genital papillae and to the terminal position of PS segment can be dismissed as result of convergent evolution. Our analyses substantially narrow the remaining available hypotheses on eriophyoid relationships and provide insights on the early evolution of acariform mites.
Abstract
Metamorphosis is a key innovation allowing the same species to inhabit different environments and accomplish different functions, leading to evolutionary success in many animal groups. ...Astigmata is a megadiverse lineage of mites that expanded into a great number of habitats via associations with invertebrate and vertebrate hosts (human associates include stored food mites, house dust mites, and scabies). The evolutionary success of Astigmata is linked to phoresy-related metamorphosis, namely the origin of the heteromorphic deutonymph, which is highly specialized for phoresy (dispersal on hosts). The origin of this instar is enigmatic since it is morphologically divergent and no intermediate forms are known. Here we describe the heteromorphic deutonymph of
Levantoglyphus sidorchukae
n. gen. and sp. (Levantoglyphidae fam. n.) from early Cretaceous amber of Lebanon (129 Ma), which displays a transitional morphology. It is similar to extant phoretic deutonymphs in its modifications for phoresy but has the masticatory system and other parts of the gnathosoma well-developed. These aspects point to a gradual evolution of the astigmatid heteromorphic morphology and metamorphosis. The presence of well-developed presumably host-seeking sensory elements on the gnathosoma suggests that the deutonymph was not feeding either during phoretic or pre- or postphoretic periods.
In this study, the temporal and spatial trends of ten climate extreme indices were computed based on observed daily precipitation and on daily maximum and minimum temperatures at 26 weather stations ...in South Western Siberia during the period 1969–2011 and, based on projected daily maximum and minimum temperatures, during 2021–2050. The Mann–Kendall test was employed to analyze the temporal trend and a combination of multiple linear regressions and semivariogram functions were used to evaluate the regional spatial trends and the local spatial variability of climate extremes, respectively. The results show that the temperature-based climate extremes increase at a 0.05 significance level while none of the precipitation-based climate extremes did. Spatially, dominant gradients are observed along latitude: The northern taiga vegetation zone experiences a colder and wetter climate while the southern forest steppe zone is drier and hotter. Over time, a tendency towards homogenization of the regional climate is observed through a decrease of the spatial variability for most climate extreme indices. In the future, the most intense changes are anticipated for the bio-climate indicators “growing season length” and “growing degree days” in the north, while the warming indicators, “warm day” and “warm night” are expected to be high to the south.
Here we report the synthesis and biological activity of new semi-synthetic derivatives of naturally occurring glycyrrhetinic acid bearing a 2-cyano-3-oxo-1-en moiety in the A-ring and double bonds ...and carbonyl groups in the C, D and E rings. Bioassays using murine macrophage-like and tumor cells show that compound 4, which differs from Soloxolone methyl by the absence of a 9(11)-double bond in the C-ring, displays anti-inflammatory and inhibitory activities with respect to tumor cells with a high selectivity index value.
The object of this study is the interaction of the cyclic anhydride 2 of (18α,19β)‐19‐hydroxy‐2,3‐secooleanane‐2,3,28‐trioic acid 28,19‐lactone (1) with primary and secondary amines. It was shown ...that the products of steric control (the corresponding 2‐amino‐2‐oxo‐3‐oic acids=2‐amides) were formed solely upon the opening of the anhydride cycle by secondary amines (Scheme 2), whereas the interaction with primary amines yielded a mixture of isomeric amides (Scheme 10). In the latter case, the solvent provided a noticeable effect on the reaction selectivity, which was demonstrated in the case of 4‐methoxybenzylamine. The interaction between the resulting 3‐amides and oxalyl chloride yielded the corresponding cyclic imides, whereas under these conditions, 2‐amides formed spiropyrrolidinetriones (Scheme 4).
A series of pyridyl‐substituted nitronyl nitroxides was synthesized and structurally characterized. A comprehensive magnetochemical and quantum chemical study of extended raw of the nitroxides with ...different substituents R in the pyridine fragment was performed. It was shown, that temperature‐dependent magnetic properties are determined by the short contacts between nitroxide groups of adjacent molecules as well as between nitroxide group and methyl substituents in the pseudo axial positions of imidazoline fragments. Quantum chemistry allows to select the appropriate model of exchange cluster for analysis of experimental magnetic data and evaluation of the exchange interaction parameters. For NN–PyCl the “order‐disorder” transition was detected by means of low temperature XRD. The difference in the experimental and calculated exchange interaction energies may serve as an indicator of temperature‐induced structural rearrangements. For instance, for methyl substituted nitronyl nitroxide NN‐PyMe structural transformations and significant changes in exchange interaction energies were observed.
A family of stable pyridyl‐substituted nitronyl nitroxides was synthesized. Magneto‐structural correlations were established by XRD, magnetochemistry and quantum chemical calculations. Low‐temperature XRD revealed phase transitions.
This study explores the antiarrhythmic and hypotensive potential of pyridyl-substituted nitronyl nitroxides derivatives, uncovering the crucial role of a single carbon moiety of the pyridine cycle ...alongside radical and charged oxygen centers of the imidazoline fragment. Notably, the introduction of fluorine atoms diminished the antiarrhythmic effect, while the most potent derivatives featured the nitronyl nitroxide pattern positioned at the third site of the pyridine cycle. Gender-dependent responses were observed in lead compounds LCF3 and LMe, with LMe inducing temporary bradycardia and hypotension specifically in female rats, and LCF3 causing significant blood pressure reduction followed by rebound in females compared to milder effects in males. Mechanistic insights point towards β1 adrenoceptor blockade as an underlying mechanism, supported by experiments on isolated rat atria. This research underscores the interplay between structure, cardiovascular effects and gender-specific responses, offering insights for therapeutic strategies for treating free radical-associated cardiovascular disorders.
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•Distinctive antiarrhythmic and hypotensive properties.•The third-positioned nitronyl nitroxide fragment is a must.•Gender variations in compound activity are observed.•Stable aqueous solutions and lower toxicity compared to established HNO donors.
The adult instar of the oribatid mite, Galumna obvia (Berlese, 1914), is redescribed in detail, on the basis of specimens from Finland. The morphology of juvenile instars of G. obvia is described and ...illustrated for the first time, and compared to that of other species of the family Galumnidae. The position of the insertion of the lamellar seta in adults proved variable in studied European populations, being either on or medial to the lamellar line. Since the genera Galumna and Pergalumna are currently distinguished only by the relative positions of the seta and line, specimens of G. obvia in some populations show an intermediate situation between other studied Galumna species - with lamellar seta on or lateral of lamellar line - and Pergalumna with lamellar seta at a distinct distance medially of lamellar line. A detailed reevaluation of the two genera is needed.
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