Lupine embryo axes under salinity stress. II. Mitochondrial proteome response

Germination is the first step of plant growth in plant life cycle. An embryonic radicle protruding the seed coat is the first part of plant which has direct contact with external environment including salt-affected soil. In embryo axes, mitochondria are the main energy producer. To understand better salinity impact on mitochondria functioning, this study was focused on the effect of NaCl stress onto mitochondria proteome. Mitochondria were isolated from yellow lupine (Lupine luteus L. ‘Mister’) embryo axes cultured in vitro for 12 h with 250 and 500 mM NaCl. Two-dimensional gel electrophoresis of mitochondrial proteins isolated from NaCl-treated axes demonstrated significant changes in proteins abundances as a response to salinity treatment. Twenty-one spots showing significant changes in protein expression profiles both under 250 and 500 mM NaCl treatment were selected for tandem mass spectrometry identification. This approach revealed proteins associated with different metabolic processes that represent enzymes of tricarboxylic acid cycle, mitochondrial electron transport chain, enzymes and proteins involved in mitochondria biogenesis and stresses response. Among proteins involved in mitochondria biogenesis, mitochondrial import inner membrane translocase, subunit Tim17/22, mitochondrial-processing peptidase subunit alpha-1, mitochondrial elongation factor Tu and chaperonins CPN60 were revealed. Finally, formate dehydrogenase 1 was found to accumulate in lupine embryo axes mitochondria under salinity. The functions of identified proteins are discussed in relation to salinity stress response, including salinity-induced PCD.     

Habitat displacement effect between two competing owl species in fragmented forests

Many owl species use the same nesting and food resources, which causes strong interspecific competition and spatio-temporal niche separation. We made use of a recent colonisation of Ural Owls (Strix uralensis) in southern Poland to compare habitat preferences of Tawny Owls (Strix aluco) allopatry and sympatry with Ural Owls. We investigated spatial niche segregation of Ural Owl and the Tawny Owl in sympatry and compared habitat preferences of Tawny Owls breeding in allopatry and sympatry. Tawny Owls breeding in sympatry with Ural Owls occupied forests with higher canopy compactness, sites located closer to forest border and to built-up areas, as well as stands with a higher share of fir and spruce and a lower share of beech as compared to sites occupied by Ural Owls. Allopatric Tawny Owls occupied sites with lower canopy compactness and bred at sites located further from forest borders and in stands with lower share of fir and spruce and a higher share of deciduous as compared to sympatric Tawny Owls. As Ural owls are dominant in relation to Tawny Owls, this indicates that the presence of Ural Owls prevents Tawny Owls from occupying deciduous-dominated and old stands located in forest interior areas, far from buildings and forest edges. The results support habitat displacement between the two species when breeding in sympatry. We also show that protection of large forest patches is crucial for the Ural Owl, a species still rare in central Europe, while small patches are occupied by the abundant Tawny Owl.     

First insights into female sperm storage duration in tardigrades

Female sperm storage is ubiquitous in the animal kingdom and it has been shown to be linked to several evolutionary processes, from postcopulatory sexual selection to dispersal. Here we report, for the first time, long‐term sperm storage in females of the tardigrade Macrobiotus polonicus. Females, isolated after a short contact with a male, were able to use the stored sperm for up to 5 weeks (mean of 2 weeks), which translates to a considerable proportion of female post‐mating longevity under controlled laboratory conditions (60% on average). Our study provides the first insights into the duration of sperm storage, an underexplored feature of the reproductive biology of tardigrades. Additionally, we discuss important considerations for reproductive studies on these non‐model animals.     

Abundance of <Emphasis Type=Italic>Stomaphis graffii</Emphasis> Cholod. (Hemiptera) on maple trees in Poland

The paper presents data on the remarkable abundance of S. graffii in the parks of the industrially transformed region of Upper Silesia, Poland. Ten new sites and 36 colonies were recorded, while only 6 sites were known so far from the whole territory of Poland. New host plant species and new ant species tending aphids were also recorded. The conclusion is that the abundance of Stomaphis species may be underestimated due to their cryptic life mode.     

Relative quantitative PCR to assess bacterial community dynamics during biodegradation of diesel and biodiesel fuels under various aeration conditions

The degradation of diesel fuel, B20 blend and biodiesel in liquid cultures by a seven-member bacterial consortium was compared under conditions with full aeration or with limited aeration with nitrate added as main electron acceptor. Community dynamics was assessed employing real-time PCR and the ddCt method for relative quantification. Biodegradation rates increased with increasing biodiesel content, but were significantly reduced under conditions with nitrate. Despite large variations in biodegradation rates, magnitude changes in population numbers were typically observed only from zero to one order, regardless the type of fuel and electron acceptor. Only Comamonadaceae and Variovorax sp. distinctly preferred aerobic conditions, and during aerobic growth showed suppression as fuel contained more biodiesel. Thus, the consortium is relatively stable and most of the degraders can shift their metabolism from hydrocarbons to biodiesel. The stability of the consortium is of interest in the context of biodiesel-mediated biodegradation of petroleum hydrocarbons.     

Response to novel object in Wistar and wild-type (WWCPS) rats

Laboratory rats react to a novel object with a rapid redirection of exploratory behaviour towards the source of the novelty and a subsequent decline of this neotic preference with repeated object exposure. Studies with wild Rattus norvegicus have shown that a novel object in a familiar cage results in avoidance reactions (neophobia) in those animals, but it is also well established that the wild R. norvegicus show strong aversive reactivity to a variety of high intensity stimuli. In this study we aimed to create low-stress conditions enabling the comparison of spontaneous exploratory behaviour directed at a novel object in male (age = 80 days) “wild-type” WWCPS rats (n = 21; fourth generation bred in captivity) and Wistar (n = 24) rats. The study involved repeated placing of individual animals in the experimental chamber for 15 (6 min) trials on consecutive days. On the 11th day the novel object was introduced. Animals were tested in darkness and without human presence. Under these conditions neither WWCPS nor Wistar have shown behavioural signs of high emotional arousal, both lines have shown comparable general levels of experimental cage exploration and the positive new object exploratory reaction was observed only in Wistar rats.     

Diversification of lupine Bradyrhizobium strains: evidence from nodulation gene trees

Bradyrhizobium strains isolated in Europe from Genisteae and serradella legumes form a distinct lineage, designated clade II, on nodulation gene trees. Clade II bradyrhizobia appear to prevail also in the soils of Western Australia and South Africa following probably accidental introduction with seeds of their lupine and serradella hosts. Given this potential for dispersal, we investigated Bradyrhizobium isolates originating from a range of native New World lupines, based on phylogenetic analyses of nodulation (nodA, nodZ, noeI) and housekeeping (atpD, dnaK, glnII, recA) genes. The housekeeping gene trees revealed considerable diversity among lupine bradyrhizobia, with most isolates placed in the Bradyrhizobium japonicum lineage, while some European strains were closely related to Bradyrhizobium canariense. The nodA gene tree resolved seven strongly supported groups (clades I to VII) that correlated with strain geographical origins and to some extent with major Lupinus clades. All European strains were placed in clade II, whereas only a minority of New World strains was placed in this clade. This work, as well as our previous studies, suggests that clade II diversified predominately in the Old World, possibly in the Mediterranean. Most New World isolates formed subclade III.2, nested in a large "pantropical" clade III, which appears to be New World in origin, although it also includes strains originating from nonlupine legumes. Trees generated using nodZ and noeI gene sequences accorded well with the nodA tree, but evidence is presented that the noeI gene may not be required for nodulation of lupine and that loss of this gene is occurring.     

Phylogeny of Itaquasconinae in the light of the evolution of the flexible pharyngeal tube in Tardigrada

The family Hypsibiidae comprises four subfamilies, among which Itaquasconinae are the most abundant in genera. Although being morphologically diverse and cosmopolitan, itaquasconins are scarcely reported and their taxonomy is entangled. Here, we present a phylogeny based on three DNA markers and morphological clues obtained from a detailed scanning electron microscopy analysis of bucco-pharyngeal apparatuses of 25 species representing seven genera. Our study revealed that (a) the polyphyletic Adropion consists of at least three evolutionary lineages, with Guidettion gen. nov. being the sister group of all remaining itaquasconins; (b) stylet supports were independently lost in Astatumen and Insulobius gen. nov.; (c) pharyngeal tube annulation can be divided into two general types, simple and complex, and is stable at the genus level, but being homoplasious (similarly to the apophyses for the insertion of stylet muscles and the shape of the claw bases), it is not useful in inferring phyletic relationships within the subfamily; and (d) Astatumen and Platicrista contain numerous similar species, challenging the current taxonomic classification; moreover, (e) three new taxa are proposed to accommodate the newly recognised lineages: Guidettion gen. nov. (the former Adropion prorsirostre group), Insulobius gen. nov. (for a new Malayan species with a mixture of Astatumen and Itaquascon traits), and Raribius gen. nov. (former Itaquascon spp. with an elongated and narrowed pharyngeal tube terminating with a spherical pharynx). The simple type of annulation is synapomorphic to Hypsibiidae, with single reversals to the uniform buccal tube in Parascon (Itaquasconinae) and in Hypsibiinae. The pharyngeal tube evolved convergently several times, and is of different character in classes Heterotardigrada and Eutardigrada.     

Family of microRNA-146 Regulates RARβ in Papillary Thyroid Carcinoma

Retinoic acid is a promising tool in adjuvant cancer therapies, including refractory thyroid cancer, and its biological role is mediated by the retinoic acid receptor beta (RARβ). However, expression of RARβ is lowered in papillary thyroid carcinoma (PTC), contributing to promotion of tumor growth and inefficiency of retinoic acid and radioactive iodine treatment. The causes of aberrant RARB expression are largely unknown. We hypothesized that the culpable mechanisms include the action of microRNAs from the miR-146 family, previously identified as significantly upregulated in PTC tumors. To test this hypothesis, we assessed the expression of RARB as well as miR-146a-5p and miR-146b-5p in 48 PTC tumor/normal tissue pairs by Taqman assay to reveal that the expression of RARB was 3.28-fold decreased, and miR-146b-5p was 28.9-fold increased in PTC tumors. Direct interaction between miRs and RARB was determined in the luciferase assay and further confirmed in cell lines, where overexpression of miR-146a-5p and miR-146b-5p caused a 31% and 33% decrease in endogenous RARB mRNA levels. Inhibition of miR-146a and miR-146b resulted in 62.5% and 45.4% increase of RARB, respectively, and a concomitant decrease in proliferation rates of thyroid cancer cell lines, analyzed in xCELLigence system.We showed that two microRNAs of the miR-146 family directly regulate RARB. Inhibition of miRs resulted in restoration of RARB expression and decreased rates of proliferation of thyroid cancer cells. By restoring RARB levels, microRNA inhibitors may become part of an adjuvant therapy in thyroid cancer patients.