Ubx promotes corbicular development in Apis mellifera

The key morphological feature that distinguishes corbiculate bees from other members of the Apidae family is the presence of the corbicula (pollen basket) on the tibial segment of hind legs. Here, we show that in the honeybee (Apis mellifera), the depletion of the gene Ultrabithorax (Ubx) by RNAi transforms the corbicula from a smooth, bristle-free concave structure to one covered with bristles. This is accompanied by a reduction of the pollen press, which is located on the basitarsus and used for packing the pollen pellet as well as a loss of the orderly arrangement of the rows of bristles that form the pollen comb. All these changes make the overall identity of workers’ T3 legs assume that of the queen. Furthermore, in a corbiculate bee of a different genus, Bombus impatiens, Ubx expression is also localized in T3 tibia and basitarsus. These observations suggest that the evolution of the pollen gathering apparatus in corbiculate bees may have a shared origin and could be traced to the acquisition of novel functions by Ubx, which in Apis were instrumental for subsequent castes and behavioural differentiation.     

Molecular evidence for historic long-distance translocations of brown bears in the Balkan region

We tested the hypothesis that brown bears were translocated from the Romanian Carpathians to Bulgaria via air transportation during the communist regime in the 1970s and 1980s. Microsatellite analysis was performed on 199 bear samples from Bulgaria and Romania. Assignment and admixture tests revealed the existence of seven genotypes (=2.8 %) in Bulgaria that were assigned with high probabilities to the Romanian population, supporting the translocation and successful establishment of Carpathian bears in Bulgaria. While we cannot rule out the possibility that active long-distance dispersal contributed to the observed pattern, the spatial distribution and sex ratio of the detected Romanian genotypes strongly favor the translocation hypothesis.     

In vitro plant regeneration from immature zygotic embryos and repetitive somatic embryogenesis in kohlrabi (Brassica oleracea var. gongylodes)

A simple and efficient protocol for direct somatic embryogenesis and plant regeneration of kohlrabi (Brassica oleracea var. gongylodes) was developed. Somatic embryos were induced from immature zygotic embryos at different developmental stages cultured on Murashige and Skoog medium supplemented with 0, 0.5, 1.0, or 1.5 mg/l 2,4-dichlorophenoxyacetic acid. Zygotic embryos at the early cotyledonary stage, which were cultured for 4 wk on plant growth regulator-free (PGR-free) medium, displayed the highest percentage of somatic embryogenesis (80.7%). Embryogenic tissue could be subcultured on the same medium for over 1 yr. Embryogenic lines derived from early cotyledonary stage zygotic embryos displayed the highest intensity of secondary embryogenesis (highest mean number of new somatic embryos per responsive somatic embryo explant). Histological analyses confirmed the direct origin of the secondary somatic embryos. Prolonged culturing of embryogenic tissue on PGR-free medium led to somatic embryo development into plantlets that were successfully acclimated in the greenhouse with a survival rate of 72.5%. Flow cytometry analysis showed no ploidy variation in 96.7% of the acclimated plants.     

Inhibitory effect of platinum and ruthenium bipyridyl complexes on porcine pancreatic phospholipase A2

Pancreatic phospholipase A(2) (PLA(2)) plays an important role in cellular homeostasis as well as in the process of carcinogenesis. Effects of metallo-drugs used as chemotherapeutics on the activity of this enzyme are unknown. In this work, the interaction between porcine pancreatic PLA(2) and two selected transition metal complexes--tetrachloro(bipyridine) platinum(IV) ([PtCl(4)(bipy)]) and dichloro (bipyridine) ruthenium(III)chloride ([RuCl(2)(bipy)(2)]Cl)--was studied. Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) and fluorescence spectroscopy have been used to analyse the enzyme activity in the absence and presence of metal complexes and to verify potential binding of these drugs to the enzyme. The tested metal complexes decreased the activity of phospholipase A(2) in an uncompetitive inhibition mode. A binding of the ruthenium complex near the active site of the enzyme could be evidenced and possible modes of interaction are discussed.     

Body size phenotypes and inflammation in the Women's Health Initiative Observational Study

Individuals with "metabolically benign" obesity (obesity unaccompanied by hypertension, dyslipidemia, and diabetes) are not at elevated 10-year risk of cardiovascular disease (CVD) compared to normal weight individuals. It remains unclear whether these obese individuals or normal weight individuals with clustering of cardiometabolic factors display heightened immune activity. Therefore, we characterized levels of acute-phase reactants (C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), white blood cell (WBC) count), adhesion molecules (E-selectin, vascular cell adhesion molecule-1), and coagulation products (fibrinogen, plasminogen activator inhibitor-1 (PAI-1)) among four body size phenotypes (normal weight with 0/1 vs. ≥2 metabolic syndrome components/diabetes and overweight/obesity with 0/1 vs. ≥2 metabolic syndrome components/diabetes) in cross-sectional analyses of 1,889 postmenopausal women from the Women's Health Initiative Observational Study (WHI-OS) nested case-control stroke study. Higher levels of all three inflammatory marker categories were found among women with overweight/obesity or ≥2 metabolic syndrome components or diabetes. Compared to normal weight women with 0 or 1 metabolic syndrome components, normal weight women with ≥2 metabolic syndrome components or diabetes were more likely to have ≥3 inflammatory markers in the top quartile (multivariate odds ratio (OR) 2.0, 95% confidence interval (CI): 1.3-3.0), as were overweight/obese women with 0 or 1 metabolic syndrome components (OR 2.3; 95% CI: 1.5-3.5). Overweight/obese women with ≥2 metabolic syndrome components or diabetes had the highest OR (OR 4.2; 95% CI: 2.9-5.9). Despite findings that metabolically benign obese individuals are not at increased 10-year risk of CVD compared to normal weight individuals, the current results suggest that overweight/obese women without clustering of cardiometabolic risk factors still possess abnormal levels of inflammatory markers.     

A single dose of neuron-binding human monoclonal antibody improves spontaneous activity in a murine model of demyelination

Our laboratory demonstrated that a natural human serum antibody, sHIgM12, binds to neurons in vitro and promotes neurite outgrowth. We generated a recombinant form, rHIgM12, with identical properties. Intracerebral infection with Theiler's Murine Encephalomyelitis Virus (TMEV) of susceptible mouse strains results in chronic demyelinating disease with progressive axonal loss and neurologic dysfunction similar to progressive forms of multiple sclerosis. To study the effects of rHIgM12 on the motor function of TMEV-infected mice, we monitored spontaneous nocturnal activity over many weeks. Nocturnal behavior is a sensitive measure of rodent neurologic function because maximal activity changes are expected to occur during the normally active night time monitoring period. Mice were placed in activity boxes eight days prior to treatment to collect baseline spontaneous activity. After treatment, activity in each group was continuously recorded over 8 weeks. We chose a long 8-week monitoring period for two reasons: (1) we previously demonstrated that IgM induced remyelination is present by 5 weeks post treatment, and (2) TMEV-induced demyelinating disease in this strain progresses very slowly. Due to the long observation periods and large data sets, differences among treatment groups may be difficult to appreciate studying the original unfiltered recordings. To clearly delineate changes in the highly fluctuating original data we applied three different methods: (1) binning, (2) application of Gaussian low-pass filters (GF) and (3) polynomial fitting. Using each of the three methods we showed that compared to control IgM and saline, early treatment with rHIgM12 induced improvement in both horizontal and vertical motor function, whereas later treatment improved only horizontal activity. rHIgM12 did not alter activity of normal, uninfected mice. This study supports the hypothesis that treatment with a neuron-binding IgM not only protects neurons in vitro, but also influences functional motor improvement.     

Overexpression of Arabidopsis cytokinin oxidase/dehydrogenase genes AtCKX1 and AtCKX2 in transgenic Centaurium erythraea Rafn.

Cytokinin oxidase/dehydrogenase (CKX) is the only known enzyme involved in cytokinin catabolism. Genes coding for two Arabidopsis CKX isoforms, AtCKX1 and AtCKX2, were introduced separately into a binary cloning vector, immobilized into Agrobacterium tumefaciens strain GV3101, and introduced into root explants of centaury (Centaurium erythraea Rafn.). The integration of each transgene was confirmed by genomic PCR. Of the total transformed explants, 30 and 28.2 % of the transformants carried AtCKX1 and AtCKX2 transgenes, respectively. Of these transformants, 50 % exhibited expression of the AtCKX1 transgene, while 64 % of transformants exhibited expression of the AtCKX2 transgene. For all analysed AtCKX transgenic centaury lines, as well as for untransformed control plants, CKX activity was higher in roots than in shoots. Expression of AtCKX in most transgenic lines contributed to enhanced levels of CKX activity in root tissues; whereas, only a few lines demonstrated increased CKX activity in shoot tissues compared to those of control plants. Moreover, overexpression of AtCKX resulted in reduced morphogenetic potential in transgenic plants, but did not significantly affect biomass production in comparison to untransformed control plants.     

Divergent patrilineal signals in three Roma populations

Previous studies have revealed that the European Roma share close genetic, linguistic and cultural similarities with Indian populations despite their disparate geographical locations and divergent demographic histories. In this study, we report for the first time Y-chromosome distributions in three Roma collections residing in Belgrade, Vojvodina and Kosovo. Eighty-eight Y-chromosomes were typed for 14 SNPs and 17 STRs. The data were subsequently utilized for phylogenetic comparisons to pertinent reference collections available from the literature. Our results illustrate that the most notable difference among the three Roma populations is in their opposing distributions of haplogroups H and E. Although the Kosovo and Belgrade samples exhibit elevated levels of the Indian-specific haplogroup H-M69, the Vojvodina collection is characterized almost exclusively by haplogroup E-M35 derivatives, most likely the result of subsequent admixture events with surrounding European populations. Overall, the available data from Romani groups points to different levels of gene flow from local populations.     

Relevance of the ability of fructose 1,6-bis(phosphate) to sequester ferrous but not ferric ions

The cytoprotective activity of F16BP has been documented in severe conditions such as convulsions, reperfusion injury, septic shock, diabetic complications, hypothermia-induced injury, UV-provoked skin damage and in other processes including apoptosis and excitotoxicity. F16BP shows very efficient cytoprotective activity in astroglial cells exposed to H₂O₂-provoked oxidative stress and during neuronal injury caused by hypoxic conditions. As most of the aforementioned processes involve iron activity-related conditions, we investigated the ferric and ferrous iron binding properties of F16BP under physiological conditions using ³¹P NMR and EPR spectroscopy. Our results indicate that cytoprotective F16BP activity is predominantly based on ferrous iron sequestration. ³¹P NMR spectroscopy of F16BP employing paramagnetic properties of iron clearly showed that F16BP forms stabile complexes with Fe²⁺ which was verified by EPR of another divalent cation—Mn²⁺. On the other hand, F16BP does not sequester ferric iron nor does it increase its redox activity as shown by ³¹P NMR and EPR spin-trapping. Therefore, F16BP may be beneficial in neurodegenerative and other conditions that are characterised by ferric iron stores and deposits.     

Profiling of Parkin-Binding Partners Using Tandem Affinity Purification

Parkinson''s disease (PD) is a progressive neurodegenerative disorder affecting approximately 1–2% of the general population over age 60. It is characterized by a rather selective loss of dopaminergic neurons in the substantia nigra and the presence of α-synuclein-enriched Lewy body inclusions. Mutations in the Parkin gene (PARK2) are the major cause of autosomal recessive early-onset parkinsonism. The Parkin protein is an E3 ubiquitin ligase with various cellular functions, including the induction of mitophagy upon mitochondrial depolarizaton, but the full repertoire of Parkin-binding proteins remains poorly defined. Here we employed tandem affinity purification interaction screens with subsequent mass spectrometry to profile binding partners of Parkin. Using this approach for two different cell types (HEK293T and SH-SY5Y neuronal cells), we identified a total of 203 candidate Parkin-binding proteins. For the candidate proteins and the proteins known to cause heritable forms of parkinsonism, protein-protein interaction data were derived from public databases, and the associated biological processes and pathways were analyzed and compared. Functional similarity between the candidates and the proteins involved in monogenic parkinsonism was investigated, and additional confirmatory evidence was obtained using published genetic interaction data from Drosophila melanogaster. Based on the results of the different analyses, a prioritization score was assigned to each candidate Parkin-binding protein. Two of the top ranking candidates were tested by co-immunoprecipitation, and interaction to Parkin was confirmed for one of them. New candidates for involvement in cell death processes, protein folding, the fission/fusion machinery, and the mitophagy pathway were identified, which provide a resource for further elucidating Parkin function.