On new Jurassic Rissooidea and Zygopleuroidea convergently similar to them (Gastropoda: Pectinibranchia)

A new genus, Boreomica gen. nov., is established; it comprises small-sized gastropods widespread in the Jurassic of the Russian Plate, the taxonomic position of which was ambiguously treated by previous authors. The new genus is assigned to the family Rissoidae. The species composition and stratigraphical and geographical distribution of the genus and its species are discussed. From the Jurassic of the Russian Plate, Callovian Boreomica exigua (Gerasimov, 1992), the type species of the genus, and Kimmeridgian–Volgian Boreomica undulata (Tullberg, 1881), and members of the genus without species status from the Bathonian and Upper Oxfordian are described. Conchological polymorphism of species connected with their eurybiontic characteristics is discussed. Based on the study of samples of the species B. exigua from different types of facies, two subspecies are recognized, B. exigua exigua and B. exigua arenosa subsp. nov. Finds of gastropods morphologically similar to Boreomica are discussed: Katosira? sp. from Mitta et al., 2004, “Procerithium?” volgense Gerasimov, 1955, “Eulima” pusilla Tullberg, 1881, and “Hudlestonella” caleptra sensu Gerasimov, 1992 are considered. It is concluded that E. pusilla and H. caleptra are unknown zygopleurids, Katosira? sp. is likely a poorly preserved Katosira, and “Procerithium?” volgense is represented by a mixture of several species belonging to different genera: several zygopleurid species, the rissoids Boreomica undulata and Bralitzia. Shells of P. volgense in the P.A. Gerasimov’s collection from the Craspedites nodiger Zone are described as Laevipleura sp.     

Protective effect of fucoidans from tropical seaweeds against oxidative stress in HepG2 cells

Fucoidans are sulfated polysaccharides with proven pharmacological effects localized in the cell wall of marine brown algae. The majority of studies have been performed with temperate brown algal species, but in recent years, the evaluation of species from tropical areas has been growing. The aim of this study was to determine the protective effect of fucoidans extracted from the tropical brown seaweeds Dictyota ciliolata, Padina sanctae-crucis, and Sargassum fluitans, against oxidative stress (OS). The D. ciliolata fucoidan (FDc) exhibited the highest reactive oxygen species (ROS) scavenging activity (26%), followed by P. sanctae-crucis fucoidan (FPs) (22%) and S. fluitans fucoidan (FSf) (14%). No cytotoxic effect was detected for any of the extracted fucoidans at a concentration of 2 mg mL^?1. Not only did the fucoidans tested show protective effect against OS by reducing ROS generation, but they also increased the glutathione (GSH) level and restored catalase (CAT) activity. Fucoidans obtained from tropical seaweeds could be used as a potential natural ingredient for functional foods.     

First gall midges (Diptera,Cecidomyioidea) from Late Cretaceous amber of the Taimyr Peninsula

Gall midges from Santonian amber of Yantardakh (Taimyr Peninsula) are investigated for the first time. Eight new genera and eight new species belonging to five tribes of the subfamily Micromyinae (Lestremiidae) are described. These are Caputmunda yantardakhica gen. et sp. nov. (Catochini), Cretoperomyia taimyrica gen. et sp. nov. (Peromyiini), Palaeostrobliella dmitrii gen. et sp. nov., Yantardakhiella pusilla gen. et sp. nov., and Zherikhiniella pedicellata gen. et sp. nov. (Strobliellini), Menssana norilsk gen. et sp. nov. (Micromyini), and Cretomycophila ekaterinae gen. et sp. nov., and Corporesana khatanga gen. et sp. nov. (Aprionini). A representative of Porricondylinae (Cecidomyiidae, Porricondylinae, Holoneurini) is recorded. The diagnoses based on morphometric parameters of tribes and previously established genera are emended. The species composition of gall midges from three Cretaceous amber faunas of different ages are analyzed.     

DNA analysis reveals rich diversity of <Emphasis Type="Italic">Hydnotrya</Emphasis> with emphasis on the species found in China

Molecular analysis of the truffle genus Hydnotrya was conducted with nrDNA-ITS sequences available including newly generated sequences from Chinese specimens. Twenty-one phylotypes were recognized with the threshold of 97% ITS identity. Seven phylotypes corresponded to the described species, H. bailii, H. cerebriformis, H. cubispora, H. laojunshanensis, H. michaelis, H. cf. variiformis, and H. tulasnei, and four phylotypes represented by Chinese specimens were described and illustrated as new species, i.e., H. badia, H. brunneospora, H. nigricans, and H. puberula. The remaining ten phylotypes may represent undescribed species. Moreover, the 21 phylotypes grouped into four distinct clades each having as core species H. cerebriformis, H. cubispora, H. michaelis, and H. tulasnei, respectively, which were strongly supported by phylogenetic analysis and morphological characterization.     

Chemical defences of native European coccinellid eggs against intraguild predation by the invasive Asian coccinellid, <Emphasis Type="Italic">Harmonia axyridis</Emphasis> (Pallas)

Harmonia axyridis (Pallas) is a coccinellid of Asian origin that has recently invaded substantial parts of Europe and is suspected to affect native coccinellid populations through intraguild predation and competition for food. Previous work has shown that two species from the Calvia genus appeared to be well protected against H. axyridis predation. To deepen our understanding on chemical protection of Calvia spp. and the predation risk by H. axyridis, we tested for susceptibility and palatability of Calvia spp. and H. axyridis eggs against predation by H. axyridis neonate larvae. Results show that eggs of C. quatuordecimguttata were mostly not eaten by H. axyridis, while eggs of the congeneric C. decemguttata were found to be largely unprotected against predation by the invasive coccinellid. We also observed that H. axyridis first instars successfully cannibalized on conspecific eggs. Removing the surface chemicals from C. quatuordecimguttata eggs resulted in significantly reduced protection from being preyed upon by H. axyridis, while applying these extracts onto C. decemguttata and H. axyridis eggs resulted in increased protection against H. axyridis larvae. The importance of surface chemicals in the interactions between H. axyridis and native coccinellids was confirmed by GC–MS analysis, showing a high diversity of hydrocarbons located on the surface of C. quatuordecimguttata eggs, i.e. more than twice as many when compared to C. decemguttata. Survival of H. axyridis larvae feeding on eggs of C. quatuordecimguttata, C. decemguttata or conspecific eggs, from which surface chemicals were removed by washing them with hexane, was not different from survival on unwashed eggs.     

Heritable bacterial endosymbionts in native and invasive populations of <Emphasis Type="Italic">Harmonia axyridis</Emphasis>

Harmonia axyridis Pallas (1773) (Coleoptera: Coccinellidae) is the well-studied system of invasive insect species. Native and invasive parts of the area of H. axyridis are isolated geographically. We studied the species composition and the distribution of bacterial symbionts Spiroplasma and Rickettsia in seven localities of the native area and six localities of the invasive area of H. axyridis. Rickettsia was detected in H. axyridis populations for the first time. We found that the proportion of beetles infected with Rickettsia in native and invasive populations of H. axyridis is about 0.03. Spiroplasma was found only in native populations of H. axyridis. The proportion of infected individuals with Spiroplasma in native populations of H. axyridis is about 0.08. All studied native populations of H. axyridis are infected with Spiroplasma, while all invasive populations are not. We discuss the possible influence of Spiroplasma and Rickettsia in the formation of invasive populations of H. axyridis.     

Reasserting the priority of <Emphasis Type="Italic">Hypericum cordiforme</Emphasis> A.St.-Hil. (Hypericaceae) over <Emphasis Type="Italic">H. cordatum</Emphasis> (Vell.) N.Robson

Priority concerning the publication of St. Hilaire’s name Hypericum cordiforme over H. cordatum is confirmed since its effective publication in Flora Brasiliae Meridionalis (1828) predates the publication of Vellozo’s name Receveura cordata, the basionym of H. cordatum, in Florae fluminensis (1829). We also provide a second-step lectotypification for H. cordiforme and a lectotypification and epitypification for Receveura cordata. Hypericum cordiforme var. genuinum is for the first time determined to be an invalid name, and H. cordatum subsp. kleinii is placed in the synonymy of H. cordiforme.     

Response of effective quantum yield of photosystem 2 to <Emphasis Type="Italic">in situ</Emphasis> temperature in three alpine plants

The response of effective quantum yield of photosystem 2 (ΔF/F_m’) to temperature was investigated under field conditions (1 950 m a.s.l.) in three alpine plant species with contrasting leaf temperature climates. The in situ temperature response did not follow an optimum curve but under saturating irradiances [PPFD >800 µìmol(photon) m^?2s^?1] highest ΔF/F_m’ occurred at leaf temperatures below 10°C. This was comparable to the temperature response of antarctic vascular plants. Leaf temperatures between 0 and 15°C were the most frequently (41 to 56%) experienced by the investigated species. At these temperatures, ΔF/F_m’ was highest in all species (data from all irradiation classes included) but the species differed in the temperature at which ΔF/F_m’ dropped below 50% (Soldanella pusilla >20°C, Loiseleuria procumbens >25°C, and Saxifraga paniculata >40°C). The in situ response of ΔF/F_m’ showed significantly higher ΔF/F_m’ values at saturating PPFD for the species growing in full sunlight (S. paniculata and L. procumbens) than for S. pusilla growing under more moderate PPFD. The effect of increasing PPFD on ΔF/F_m’, for a given leaf temperature, was most pronounced in S. pusilla. Despite the broad diurnal leaf temperature amplitude of alpine environments, only in S. paniculata did saturating PPFD occur over a broad range of leaf temperatures (43 K). In the other two species it was half of that (around 20 K). This indicates that the setting of environmental scenarios (leaf temperature×PPFD) in laboratory experiments often likely exceeds the actual environmental demand in the field.     

A PCR-based analysis of plant DNA reveals the feeding preferences of <Emphasis Type="Italic">Apolygus lucorum</Emphasis> (Heteroptera: Miridae)

The mirid bug Apolygus lucorum (Meyer-Dür) (Heteroptera: Miridae) is a severe pest of cotton and other crops in China. The feeding preferences of this pest are unclear due to its frequent movement among different host plants and the inconspicuous signs of its feeding. Here, we present results of a field trial that used direct observation of bug densities and a PCR-based molecular detection assay to detect plant DNA in bugs to explore relationships between A. lucorum population abundance and its feeding preference between two host plants, Humulus scandens (Loureiro) Merrill and Medicago sativa L. The field-plot samples showed that A. lucorum adults generally prefer flowering host plants. Its density was significantly higher on flowering H. scandens than on seedlings of M. sativa, and a similarly higher bug density was observed on flowering M. sativa than on seedlings of H. scandens. In the laboratory, we designed two pairs of species-specific primers targeting the trnL-F region for H. scandens and M. sativa, respectively. The detectability of plant DNA generally decreased with time post-feeding, and the half-life of plant DNA detection (DS₅₀) in the gut was estimated as 6.26 h for H. scandens and 3.79 h for M. sativa with significant differences between each other. In mirid bugs exposed to seedlings of H. scandens and flowering M. sativa, the detection rate of M. sativa DNA was significantly higher than that of H. scandens. Meanwhile, in mirid bugs exposed to seedlings of M. sativa and flowering H. scandens, a significantly higher detection rate of H. scandens DNA was found. We developed a useful tool to detect the remaining plant food species specifically from the gut of A. lucorum in the current study. We provided direct evidence of its feeding preference between H. scandens and M. sativa at different growth stages, which strongly supported a positive correlation between population abundance and feeding preference of A. lucorum on different plants under field conditions. The findings provide new insights into the understanding of A. lucorum’s feeding preference, and are helpful for developing the strategies to control this pest.     

The fitness of the cotton mealybug <Emphasis Type="Italic">Phenacoccus solenopsis</Emphasis> (Tinsley) is reduced after feeding on virus-infected <Emphasis Type="Italic">Hibiscus rosa</Emphasis>-<Emphasis Type="Italic">sinensis</Emphasis>

The cotton mealybug Phenacoccus solenopsis (Tinsley) and Cotton leaf curl Multan virus (CLCuMV), serious threats to economic crops and garden plants, have invaded southern China and widely infected Hibiscus rosa-sinensis. Whether an inter-species connection has facilitated the invasion process is unclear. In this study the interaction between P. solenopsis and H. rosa-sinensis infected with CLCuMV was investigated in the laboratory. We observed that 1st and 2nd instar nymphs of P. solenopsis preferred to feed on healthy H. rosa-sinensis leaves, whereas 3rd instar nymphs and female adults had no preference between healthy and virus-infected H. rosa-sinensis leaves. The developmental time of each P. solenopsis developmental stage increased significantly after feeding on infected H. rosa-sinensis leaves (p < 0.05). In particular, the development time for 2nd instar female and male nymphs and 3rd instar female nymphs increased by approximately twofold. The generation time of female mealybugs increased from 25.84 d on healthy H. rosa-sinensis to 32.12 d when feeding on CLCuMV-infected H. rosa-sinensis, and the survival rate decreased from 71.04 % on healthy H. rosa-sinensis to 5.80 % on infected plants. Nymph survival was most affected by feeding on infected plants. Additionally, the fecundity of female mealybugs feeding on infected H. rosa-sinensis decreased by 47.8 %. Thus, feeding on CLCuMV-infected H. rosa-sinensis significantly decreased the biological fitness and invading and colonizing abilities of P. solenopsis.     

Genome-wide association studies provide insights on genetic architecture of resistance to leaf rust in a worldwide barley collection

We assembled an international barley panel comprising 282 entries from 26 countries with various levels of field resistance to leaf rust caused by Puccinia hordei. The panel was screened for leaf rust response with an array of pathotypes at the seedling stage, and at the adult plant stage in multiple environments (2013–2015) in Australia and Uruguay, and genotyped using >?13 K polymorphic DArT-Seq markers. Multipathotype testing in the greenhouse postulated the presence of seedling resistance genes Rph1, Rph2, Rph3, Rph4, Rph7, Rph9.am, Rph12, Rph14, Rph15, Rph19, and Rph25. Genome-wide association studies (GWAS) based on field data identified 13 QTLs significantly associated with DArT-Seq markers on chromosomes 2H (Rph_G_Q1, Rph_G_Q2, Rph_G_Q3, and Rph_G_Q4), 4H (Rph_G_Q5), 5H (Rph_G_Q6, Rph_G_Q7, Rph_G_Q8), 6H (Rph_G_Q9 and Rph_G_Q10), and 7H (Rph_G_Q11, Rph_G_Q12, and Rph_G_Q13). Three QTLs (Rph_G_Q3, Rph_G_Q5, and Rph_G_Q6) were detected under all environments, whereas the other ten were variable, being detected in 1–4 environments; Rph_G_Q1 and Rph_G_Q13 being detected only in Uruguay. Among the three QTLs detected under all environments, Rph_G_Q6 on chromosome 5H had the largest effect and corresponded to a region where the cataloged APR gene Rph20 is located. Rph_G_Q3 and Rph_G_Q5 detected on chromosome 2H and 4H aligned with QTLs reported in at least three previous studies. The studies provide useful information towards better understanding of the genetic architecture of seedling and adult plant resistance to leaf rust in diverse global barley germplasm.     

Revision of Cretaceous Radiolarians of the Family Hagiastridae from Lipman’s Collection

Based on the Lipman’s hagiastrid collection and original material, Late Cretaceous holotypes of the genera Histiastrum Ehrenberg, Hagiastrum Haeckel, and Tesserastrum Haeckel are revised. Histiastrum aster Lipman, H. cruciferum Lipman, H. membraniferum Lipman, H. latum Lipman, H. tetracanthum Lipman, H. tumeniense Lipman, Hagiastrum crux Lipman, and Tesserastrum quadratum Lipman are transferred to the genus Crucella Pessagno. A new species, Rhombastrum lipmanae sp. nov., is described. It is shown that Crucella lata (Lipman) and C. crux (Lipman) are Santonian–Campanian index species and C. crucifera (Lipman), C. tetracantha (Lipman), C. tumeniensis (Lipman), and Rhombastrum lipmanae sp. nov. are markers of the Campanian Boreal Realm.     

Diversity within the <Emphasis Type="Italic">Hygrophorus agathosmus</Emphasis> group (Basidiomycota,Agaricales) in Northern Europe

The North European species of the Hygrophorus agathosmus group in subsection Tephroleuci were studied. Three new species are identified based on morphology, ecology and sequence data. Two species are associated with Pinus spp. One of these is described here as H. suaveolens, while the other one is only known from one locality in the Nordic countries and seems to have a more South European distribution range. A closely related sister species to H. agathosmus is identified based on ITS sequence data, H. cf. agathosmus. It is confirmed to have an intercontinental distribution range and to be associated with Picea spp. probably on more acidic to neutral soil, whereas H. agathosmus s.s. has a more limited North-East European distribution range and occurs in older and rich Picea abies forests. A neotype for H. agathosmus is here selected from South Sweden. Hygrophorus agathosmus f. albus and H. agathosmus f. aureofloccosus are confirmed as forms. No genetic differences in the ITS region between specimens with grey cap colour and the two forms were observed. A key to the species in Northern Europe is provided.     

Determining the effects of life stage,shared prey density and host plant on intraguild predation of a native lacewing (<Emphasis Type="Italic">Chrysoperla carnea</Emphasis>) by an invasive coccinellid (<Emphasis Type="Italic">Harmonia axyridis</Emphasis>)

Negative impacts of non-native Harmonia axyridis (Pallas) on members of the native aphid enemy guild have been widely hypothesised but mainly only assessed with other coccinellid species, and mostly in small experimental arenas. Here we investigated the interactions between H. axyridis and Chrysoperla carnea Stephens larvae. In small-scale (Petri dish) arenas 2nd-instar C. carnea were at risk of predation from larval (2nd and 4th-instar) and adult (male and female) H. axyridis while 3rd-instar C. carnea were only at minimal risk from 4th-instar and adult female H. axyridis. Plant species, aphid species and aphid density did not affect intraguild predation of 2nd-instar C. carnea by 4th-instar and adult H. axyridis in mesocosm experiments. Chrysoperla carnea consumed similar numbers of Megoura viciae Buckton, Aphis fabae Scop. and Acyrthosiphon pisum Harris aphids while H. axyridis consumed fewer M. viciae than the other two species. The greatest suppression of A. pisum was achieved in treatments with both C. carnea and H. axyridis. Life stage and the sex of H. axyridis as well as the life stage of C. carnea are important variables affecting intraguild predation and these attributes should be considered when assessing the potential threat of other potentially invasive alien predators.     

Dynamic changes of histone H3 lysine 9 following trimethylation in bovine oocytes and pre-implantation embryos

Objectives

We have examined dynamic changes of histone H3 lysine 9 following trimethylation (H3K9me3), the mRNA expression levels of SUV39H1 and SUV39H2 in bovine oocytes and the role in the development of in vitro fertilization (IVF) pre-implantation embryos.

Results

There were strong H3K9me3 signals in germinal vesicle (GV) oocytes but no signals in MII oocytes. H3K9me3 signals were maintained during IVF pre-implantation embryo development. SUV39H1 and SUV39H2 showed significantly higher mRNA expression levels in GV oocytes than MII oocytes (P < 0.01). SUV39H1 showed high mRNA expression level in two-cell embryos, however, SUV39H2 showed high mRNA expression level in four-cell embryos. In other development stage, SUV39H1 and SUV39H2 showed low expression levels.

Conclusion

Bovine IVF pre-implantation embryos maintain strong H3K9me3 signals and SUV39H1 and SUV39H2 are highly expressed at the early development stage of pre-implantation embryos.

     

Deletion of <Emphasis Type="Italic">ldh</Emphasis>A and <Emphasis Type="Italic">ald</Emphasis>H genes in <Emphasis Type="Italic">Klebsiella</Emphasis><Emphasis Type="Italic">pneumoniae</Emphasis> to enhance 1,3-propanediol production

Objectives

To improve 1,3-propanediol (1,3-PD) production and reduce byproduct concentration during the fermentation of Klebsiella pneumonia.

Results

Klebsiella. pneumonia 2-1ΔldhA, K. pneumonia 2-1ΔaldH and K. pneumonia 2-1ΔldhAΔaldH mutant strains were obtained through deletion of the ldhA gene encoding lactate dehydrogenase required for lactate synthesis and the aldH gene encoding acetaldehyde dehydrogenase involved in the synthesis of ethanol. After fed-batch fermentation, the production of 1,3-PD from glycerol was enhanced and the concentrations of byproducts were reduced compared with the original strain K. pneumonia 2-1. The maximum yields of 1,3-PD were 85.7, 82.5 and 87.5 g/l in the respective mutant strains.

Conclusion

Deletion of either aldH or ldhA promoted 1,3-PD production in K. pneumonia.