Dosage compensation (DC) in Drosophila equalizes X chromosome-linked gene expression via the male-specific lethal complex, which acetylates histone 4 lysine-16 on the male X chromosome. How DC is established during early embryogenesis remains obscure, largely due to the difficulty of obtaining sufficient sex-specific material at early embryonic stages. Here, we developed a high-throughput embryo sorting strategy and combined newly synthesized RNA-sequencing and RNA polymerase II (Pol II) profiling to investigate the mechanisms underlying the onset of DC in vivo. We found that changes in transcription initiation occur before detectable differences in transcriptional pausing or elongation and represent the primary determinant of enhanced mRNA output during DC establishment. It had hitherto been unclear whether DC establishment and maintenance exerted similar or distinct effects on transcriptional kinetics. Extending genome-wide profiling to S2 cells, we uncovered Pol II initiation as a general principle underlying both inception and perpetuation of DC-driven transcriptional up-regulation.

ABSTRACT. This study aims at the recovery of non-ferrous metals from pyrometallurgy copper slag enriched in diopside, fayalite, and protomangano-ferro-anthophyllite and containing 0.36 % copper, 1.93 % zinc, and 0.09 % cobalt by bioleaching with silicate-solubilising strain Bacillus megaterium CCM 3360. Two techniques of bioleaching were applied: (i) direct one-step bioleaching, where the bacterial strain was cultivated in an Ashby medium and the presence of copper slag; (ii) indirect bioleaching of copper slag with spent medium obtained after separation of the bacterial cells. The results revealed that 5 % pulp density was the optimal out of the tested pulp densities (5-10%), as 15 days was the optimal duration for the direct bioleaching and 3 days for the indirect technique. The formation of biofilm on the surface of copper slag particles was the primary mechanism of the leaching of non-ferrous metals, and their recovery was between 41.7-48.7%. Indirect leaching with bacterial metabolites played a secondary role in base metals leaching. Keywords: copper slag, Bacillus, bioleaching, silicate bacteria

Copper slag, a by-product of copper ore and concentrate smelting, is rich in non-ferrous metals; therefore, it has been considered a valuable raw material in recent years. This study aimed to compare the extraction of zinc, copper, and cobalt from two types of copper slag from a dump located near the village of Eliseyna, Bulgaria, which differ in mineralogical composition and chemical content, using indirect bioleaching with a spent medium of Aspergillus niger and Penicillium ochrochloron. Chemical leaching with sulphuric acid revealed that zinc and cobalt existed mainly as an acidic-soluble phase in both types of copper slag. In contrast, it contained 50–75% of the total copper content. Each fungal species was cultivated for one week, and the biomass and the spent medium were separated a week later. Owing to the production of a higher concentration of citric acid, A. niger facilitated more efficient base metal recovery. However, their effective recovery from the acidic-soluble phase required leaching at a 5% pulp density and supplementing the spent medium with sulphuric acid. The temperature played a secondary role. Conclusions: Non-ferrous metal extraction from copper slag exposed to weathering using a spent medium supplemented with sulphuric acid was achieved under milder leaching conditions and with better selectivity. In contrast, slag unaffected by weathering behaved as a refractory due to the worsened results of base metal extraction under similar experimental conditions.

The NSL complex is a transcriptional activator. Germline-specific knockdown of NSL complex subunits NSL1, NSL2, and NSL3 results in reduced piRNA production from a subset of bidirectional piRNA clusters, accompanied by widespread transposon derepression. The piRNAs most transcriptionally affected by NSL2 and NSL1 RNAi map to telomeric piRNA clusters. At the chromatin level, these piRNA clusters also show decreased levels of H3K9me3, HP1a, and Rhino after NSL2 depletion. Using NSL2 ChIP-seq in ovaries, we found that this protein specifically binds promoters of telomeric transposons HeT-A, TAHRE, and TART Germline-specific depletion of NSL2 also led to a reduction in nuclear Piwi in nurse cells. Our findings thereby support a role for the NSL complex in promoting the transcription of piRNA precursors from telomeric piRNA clusters and in regulating Piwi levels in the Drosophila female germline.

Laden leach solution, generated from bioleaching of pyrometallurgical copper slags with a mixed culture of moderately thermophilic bacteria in a bioreactor, contains several base metals (Cu, Co, Zn) and a very high concentration of iron (33,9 g/ L). Further processing of cobalt and zinc to the respective final products requires preparatory iron removal from the laden leach solution. The direct iron removal from that solution as goethite was unacceptable because of the significant co-precipitation of copper and cobalt from the solution. The main aim of this paper is to study magnetite (Fe3O4) synthesis as an approach for iron removal to a value-added product as a step of the processing of a laden solution generated due to the bioleaching of non-ferrous metals in a bioreactor. Ferrous iron oxidation to ferric state was efficient when the addition of H2O2 (30 %) was combined with maintaining the pH 3,1-3,3 with NaOH and air purging. Solvent extraction with 25 % D2EHPA and 7,5 % TBP dissolved in kerosene efficiently separated the dissolved iron and the base metals from the processed solution. However, in the presence of H2, the iron was stripped from the organic solvent with low acid consumption. The applied precise control of the chemical precipitation and oxidation processes at 50 degrees Celsius allowed the iron content (11,7 g/ L) in the stripping solution to be removed efficiently as magnetite (Fe3O4). Based on the chemical content of iron, copper and sulphur, the synthesised nanoparticles of magnetite could be applicable in many sectors (steel, chemical, and electronics).

The study aimed to determine the effect of the acid mine drainages` flow rate on the iron adsorption by ion-exchange resin LEWATIT MonoPlus TP 207 in a fixed-bed column and to evaluate which widely used models describe that process better. The ferrous iron was preliminary chemically oxidised by H2O2 and Na2CO3 addition and increased pH to 3.50 combined with the solution purging with air. After assembling fixed-bed columns, their bed volume (BV) was determined. The treated mining solution was delivered to fixed-bed columns by a peristaltic pump at 2.0, 3.0, and 4.0 BV flow rates. The iron adsorption efficiency on the LEWATIT resin was studied depending on the applied flow rate and the volume being treated. The experimental data obtained were modelled using the Bohart-Adams, Thomas, Yoon-Nelson, and Clark models. The results showed that at constant experimental conditions (temperature, ferric iron concentration, and pH), the applied flow rate had a significant effect on the parameters which are important from a practical (efficiency of iron removal, (Y); equilibrium iron and equilibrium copper contents of the resin, (qeq)) and a theoretical point of view (rate constants (kBA, kTh, kYN, r); time of breakthrough (τ)). The Yoon-Nelson and Clark models were the models that best fitted the experimental results.

The paper presents evidence of Roman marble production in the Balkan region, specifically from the south-eastern Rhodope Mountain area (modern Bulgaria) and Armira. Although the Roman marble trade and production in antiquity are well known in Prokonnesos, Thasos, and several other production sites, marble deposits from inland Thrace have received far less attention. In 2018–2019, a systematic survey of south-eastern Bulgaria (Roman Thrace) was carried out by our team in collaboration with the National Archaeological Institute with Museum in Bulgaria. White marble quarries and outcrops were investigated in situ with the goal of characterizing the macroscopic qualities of the stone. Quarry samples were collected and analyzed through various techniques—petrography, isotopic, and chemical analyses—and compared with the architectural decorative marble and artifacts from the Roman villa at Armira. We demonstrate that the geochemical and petrographic features of these samples indicate a marble provenance restricted to a few selected sources. We conclude that the local marble from the Armira and Kamilski Dol quarries was widely used for the complete architectural program of the Roman villa of Armira.

A large dump consisting of low-grade uranium ores and mining wastes located in the uranium deposit Kurilo, Bulgaria, was after rainfall a source of acid drainage waters containing toxic heavy metals, radionuclides, arsenic and sulphates in concentrations much higher than the relevant permissible levels. The generation of these polluted waters was connected with the presence of several acidophilic chemolithotrophic bacteria, which oxidized the sulphide minerals and tetravalent uranium present in the dump. The attempts to prevent these processes by the addition of alkalizing minerals to the dump had only a temporary and a partial effect. For that reason the polluted waters were subjected to an efficient treatment by means of a passive system of the type of the constructed wetlands.

The study aimed to determine the optimal conditions for adsorption and elution of iron from acid mine drainage by ion-exchange resin LEWATIT MonoPlus TP 207 under a batch regime of operation. Langmuir's sorption equation was employed to analyse the equilibrium data from the experiments. The data fitting demonstrated that the process obeyed pseudo-second-order kinetics with a linear regression coefficient (R2) of 0.9999. Because of the higher demand for hydrochloric solution (100 g/ L) for the ferric iron elution, we studied the effect of the preliminary stage of galvanic elution of Fe(III) to Fe(II) in the presence of H2. In that way, a slightly acidic solution (30 g/ L) was sufficient to desorb more than 95 % of iron from ion exchange resin LEWATIT MonoPlus TP 207 at a temperature of 70 °C.

Sex chromosomes induce potentially deleterious gene expression imbalances that are frequently corrected by dosage compensation (DC). Three distinct molecular strategies to achieve DC have been previously described in nematodes, fruit flies, and mammals. Is this a consequence of distinct genomes, functional or ecological constraints, or random initial commitment to an evolutionary trajectory? Here, we study DC in the malaria mosquito Anopheles gambiae The Anopheles and Drosophila X chromosomes evolved independently but share a high degree of homology. We find that Anopheles achieves DC by a mechanism distinct from the Drosophila MSL complex-histone H4 lysine 16 acetylation pathway. CRISPR knockout of Anopheles msl-2 leads to embryonic lethality in both sexes. Transcriptome analyses indicate that this phenotype is not a consequence of defective X chromosome DC. By immunofluorescence and ChIP, H4K16ac does not preferentially enrich on the male X. Instead, the mosquito MSL pathway regulates conserved developmental genes. We conclude that a novel mechanism confers X chromosome up-regulation in Anopheles Our findings highlight the pluralism of gene-dosage buffering mechanisms even under similar genomic and functional constraints.

Iron is usually present in higher concentrations in the laden solutions and its removal and elimination to a stable phase is a severe problem in hydrometallurgy. This article analyses and compares the processes of solvent extraction and ion exchange as methods for the iron separation and concentration in a sufficient amount, which would enhance its further removal to products with potential for application to other industries. The factors affecting the goethite, hematite and magnetite processes and the area of use of the produced iron oxides are reviewed.

Before zygotic genome activation (ZGA), the quiescent genome undergoes reprogramming to transition into the transcriptionally active state. However, the mechanisms underlying euchromatin establishment during early embryogenesis remain poorly understood. Here, we show that histone H4 lysine 16 acetylation (H4K16ac) is maintained from oocytes to fertilized embryos in Drosophila and mammals. H4K16ac forms large domains that control nucleosome accessibility of promoters prior to ZGA in flies. Maternal depletion of MOF acetyltransferase leading to H4K16ac loss causes aberrant RNA Pol II recruitment, compromises the 3D organization of the active genomic compartments during ZGA, and causes downregulation of post-zygotically expressed genes. Germline depletion of histone deacetylases revealed that other acetyl marks cannot compensate for H4K16ac loss in the oocyte. Moreover, zygotic re-expression of MOF was neither able to restore embryonic viability nor onset of X chromosome dosage compensation. Thus, maternal H4K16ac provides an instructive function to the offspring, priming future gene activation.

The ability of different microorganisms to generate electricity was tested by means of a microbial fuel cell consisting of plexiglass column with two sections (anodic and cathodic) separated by a permeable barrier. The feed stream containing the potential energy sources (organic substrates) was supplied to the bottom anodic section and the effluents passed through the aerated cathodic section and continuously exited at the top. The continuous-flow treatment of the solutions containing dissolved organic substrates was connected with the gradual selection of electrochemically active bacteria related to the three principal physiological groups: sulphate reducing, iron-reducing and fermenting. The power generation by this system varied within a large area (from 125 to 710 mW/m(2)) and depended mainly on the type, form and quantity of the organic donors of electrons, the enzymatic activity of the microorganisms in the anodic section and efficiency of aeration in the cathodic section.

Confinement of the X chromosome to a territory for dosage compensation is a prime example of how subnuclear compartmentalization is used to regulate transcription at the megabase scale. In Drosophila melanogaster , two sex-specific non-coding RNAs (roX1 and roX2) are transcribed from the X chromosome. They associate with the male-specific lethal (MSL) complex 1 , which acetylates histone H4 lysine 16 and thereby induces an approximately twofold increase in expression of male X-linked genes 2 , 3 . Current models suggest that X-over-autosome specificity is achieved by the recognition of cis -regulatory DNA high-affinity sites (HAS) by the MSL2 subunit 4 , 5 . However, HAS motifs are also found on autosomes, indicating that additional factors must stabilize the association of the MSL complex with the X chromosome. Here we show that the low-complexity C-terminal domain (CTD) of MSL2 renders its recruitment to the X chromosome sensitive to roX non-coding RNAs. roX non-coding RNAs and the MSL2 CTD form a stably condensed state, and functional analyses in Drosophila and mammalian cells show that their interactions are crucial for dosage compensation in vivo. Replacing the CTD of mammalian MSL2 with that from Drosophila and expressing roX in cis is sufficient to nucleate ectopic dosage compensation in mammalian cells. Thus, the condensing nature of roX–MSL2 CTD is the primary determinant for specific compartmentalization of the X chromosome in Drosophila .

Archeological materials from the most ancient open‐pit gold mine in Europe have been investigated using mineral magnetic methods as part of the multidisciplinary research of the site. The aim of the study was to employ rock‐magnetic characteristics (magnetic susceptibility, anhysteretic remanent magnetization, isothermal remanent magnetization and various magnetic grain‐size dependent ratios) for classification of a collection of 177 samples, taken from Late Bronze age waste heaps, pristine rocks, natural soils and soils from cultural layers. Factor analysis and k‐means cluster analysis revealed that four clusters explain the best mineral magnetic data. Results from the thermomagnetic analysis and thermal demagnetization of composite isothermal remanence proved that the main magnetic minerals in the collection are magnetite/maghemite, hematite, and goethite. Based on the magnetic properties, samples from clusters 1 and 3 were identified as influenced by fire—archeological structures and waste heaps with the use of fire setting, respectively. Samples belonging to cluster 2 were dominated by goethite and hematite, thus identified as rock residues. Materials grouped in cluster 4 showed magnetic characteristics typical of natural soils and were thus related to this class of materials. The obtained clustering of the samples agreed well with their archeological assignment. Spatial distribution of cluster members across the site provides valuable environmental information for the location of the mining activities, their lateral spread and the technology used. It was concluded that magnetic mineral analysis is a precise, sensitive, and a highly effective method for characterization and classification of materials from ancient mining.

Nucleosomal organization at gene promoters is critical for transcription, with a nucleosome-depleted region (NDR) at transcription start sites (TSSs) being required for transcription initiation. How NDRs and the precise positioning of the +1 nucleosomes are maintained on active genes remains unclear. Here, we report that the Drosophila nonspecific lethal (NSL) complex is necessary to maintain this stereotypical nucleosomal organization at promoters. Upon NSL1 depletion, nucleosomes invade the NDRs at TSSs of NSL-bound genes. NSL complex member NSL3 binds to TATA-less promoters in a sequence-dependent manner. The NSL complex interacts with the NURF chromatin remodeling complex and is necessary and sufficient to recruit NURF to target promoters. Not only is the NSL complex essential for transcription, but it is required for accurate TSS selection for genes with multiple TSSs. Furthermore, loss of the NSL complex leads to an increase in transcriptional noise. Thus, the NSL complex establishes a canonical nucleosomal organization that enables transcription and determines TSS fidelity.

Haploinsufficiency and aneuploidy are two phenomena, where gene dosage alterations cause severe defects ultimately resulting in developmental failures and disease. One remarkable exception is the X chromosome, where copy number differences between sexes are buffered by dosage compensation systems. In Drosophila, the Male-Specific Lethal complex (MSLc) mediates upregulation of the single male X chromosome. The evolutionary origin and conservation of this process orchestrated by MSL2, the only male-specific protein within the fly MSLc, have remained unclear. Here, we report that MSL2, in addition to regulating the X chromosome, targets autosomal genes involved in patterning and morphogenesis. Precise regulation of these genes by MSL2 is required for proper development. This set of dosage-sensitive genes maintains such regulation during evolution, as MSL2 binds and similarly regulates mouse orthologues via Histone H4 lysine 16 acetylation. We propose that this gene-by-gene dosage compensation mechanism was co-opted during evolution for chromosome-wide regulation of the Drosophila male X.

An experimental plot containing acidic soil heavily contaminated with radionuclides (mainly uranium) and heavy metals (mainly copper, zinc and cadmium) was treated by means of an in situ biotechnological method based on the activity of the indigenous microflora, mainly of some acidophilic chemolithotrophic bacteria. The pollutants were located mainly in the upper soil layers (horizon A) and considerable portions of them were present in forms susceptible to bacterial leaching. The treatment was connected with the dissolution of pollutants and their removal from the soil profile by means of water acidified with sulphuric acid to pH of about 3.5. The bacterial activity was enhanced by suitable changes of some essential environmental factors such as pH and water, oxygen and nutrient contents in the soil. The removal of pollutants was very efficient and within 24 months their residual concentrations in the soil were decreased below the relevant permissible levels. The pregnant soil effluents containing the dissolved pollutants were efficiently cleaned up by wetlands located near the experimental plot.

ABSTRACT Phosphatidylinositol transfer proteins (PITPs) are essential regulators of PLC signalling. The PI transfer domain (PITPd) of multi-domain PITPs is reported to be sufficient for in vivo function, questioning the relevance of other domains in the protein. In Drosophila photoreceptors, loss of RDGBα, a multi-domain PITP localized to membrane contact sites (MCSs), results in multiple defects during PLC signalling. Here, we report that the PITPd of RDGBα does not localize to MCSs and fails to support function during strong PLC stimulation. We show that the MCS localization of RDGBα depends on the interaction of its FFAT motif with dVAP-A. Disruption of the FFAT motif (RDGBFF/AA) or downregulation of dVAP-A, both result in mis-localization of RDGBα and are associated with loss of function. Importantly, the ability of the PITPd in full-length RDGBFF/AA to rescue mutant phenotypes was significantly worse than that of the PITPd alone, indicating that an intact FFAT motif is necessary for PITPd activity in vivo. Thus, the interaction between the FFAT motif and dVAP-A confers not only localization but also intramolecular regulation on lipid transfer by the PITPd of RDGBα. This article has an associated First Person interview with the first author of the paper.

Copper final slags containing 0.62% Cu, 1.07% Zn, 0.08% Co and 32.5% Fe as the most essential components were subjected to chemical (by means of sulphuric acid and ferric ions) and biological leaching by means of chemolithotrophic microorganisms of three different types: mesophilic and moderate thermophilic bacteria and extreme thermophilic archaea, with temperature optimum at 37, 55 and 75 degrees Celsius, respectively. The leaching was carried out by the shake-flask technique and in agitated bioreactors. The highest rates of extraction of the non-ferrous metals and iron were achieved by means of some archaea but at relatively low pulp densities (5 – 10%). The moderate thermophilic bacteria were the most efficient for the leaching at a higher pulp density (within 15 – 20%).