Analysis of ROH patterns in the Noriker horse breed reveals signatures of selection for coat color and body size.

Overlapping runs of homozygosity (ROH islands) shared by the majority of a population are hypothesized to be the result of selection around a target locus. In this study we investigated the impact of selection for coat color within the Noriker horse on autozygosity and ROH patterns. We analyzed overlapping homozygous regions (ROH islands) for gene content in fragments shared by more than 50% of horses. Long-term assortative mating of chestnut horses and the small effective population size of leopard spotted and tobiano horses resulted in higher mean genome-wide ROH coverage (SROH ) within the range of 237.4-284.2 Mb, whereas for bay, black and roan horses, where rotation mating is commonly applied, lower autozygosity (SROH from 176.4-180.0 Mb) was determined. We identified seven common ROH islands considering all Noriker horses from our dataset. Specific islands were documented for chestnut, leopard spotted, roan and bay horses. The ROH islands contained, among others, genes associated with body size (ZFAT, LASP1 and LCORL/NCAPG), coat color (MC1R in chestnut and the factor PATN1 in leopard spotted horses) and morphogenesis (HOXB cluster in all color strains except leopard spotted horses). This study demonstrates that within a closed population sharing the same founders and ancestors, selection on a single phenotypic trait, in this case coat color, can result in genetic fragmentation affecting levels of autozygosity and distribution of ROH islands and enclosed gene content.

Removal of organics from different types of landfill leachate by ozonation.

The objective of this investigation was determination of feasibility of ozonation for treatment of leachates from municipal landfill. Efficiency of ozonation was determined for two leachates, different in age, composition and toxicity. We have studied the impact of ozonation time on removal of organics. The efficiency of treatment was monitored by COD, BOD(5) and DOC analyses, removal of nitrogen compounds, as well as changes in toxicity. Therefore, acute toxicity tests with luminiscent bacteria Vibrio fischeri, Daphnia magna and nitrifying organisms of activated sludge (ammonium oxidation) were performed prior and after ozonation experiments. It has been confirmed that longer time of ozonation does not bring significantly better results regarding treatment of young leachate (36% in 20 minutes, 42% in 120 minutes). Two steps kinetics observed resulted in minor detoxification regarding luminiscent bacteria and no changes in effects to daphnids. More effective was ozonation of the stabilized leachate. Removal of COD reached 50% in 80 minutes and 65% in 120 minutes. Detoxification was also observed. Presented research confirmed, that ozonation itself was not effective treatment methods for investigated types of leachates for reduction of their hazardous impacts to meet regulatory effluent limits.

The relationship bettween composition and toxicity of tannery wastewater.

Key toxic components have been identified in pre-treated tannery wastewater with fractionation of samples through chemical and physical means (filtration, air stripping, adsorption on activated carbon,...). The goal of each fractionation step was to reduce the toxicity due to a specific group of chemicals and compare the results to the toxicity present in the unaltered sample. Toxicity short-term tests with the invertebrate Daphnia magna and thebacterial luminescence inhibition test with Vibrio fischeri were used in combination with chemical analyses. During the toxicity identification and evaluation fractionation, a portion of the sample was pressure filtered. Treated samples contained less organic pollution and metals and were less toxic especially to Daphnia magna. For the removal of ammonia the second portion of sample was air-stripped at different pH levels. We removed 84% of ammonia at pH 11; the toxicity to both organisms decreased but ammonia did not have a deciding effect on the toxicity of tannery wastewater when the organic load was still present. The most successful procedure for toxicity removal was adsorption on powdered activated carbon. We removed organic pollution detected as COD, organic nitrogen compounds and part of the metals. Zeolite treatment was a little less successful for removing ammonia than air-stripping.

A functional cytochrome P450 lanosterol 14 alpha-demethylase CYP51 enzyme in the acrosome: transport through the Golgi and synthesis of meiosis-activating sterols.

Mammalian lanosterol 14 alpha-demethylase (CYP51) is a microsomal cytochrome P450 that demethylates lanosterol to FF-MAS, an oocyte meiosis-activating sterol and late intermediate of cholesterol biosynthesis. Herein we report CYP51 unequivocally localized to acrosomal membranes of male germ cells in mouse, bull, and ram, in which it synthesizes FF-MAS in the presence of the acrosomal form of nicotinamide adenine dinucleotide phosphate reduced-P450 reductase. In the mouse, CYP51 (53 kDa) resides in endoplasmic reticulum (ER) and Golgi during all phases of acrosome development, indicating an intracellular transport from ERs through the Golgi to the acrosome. CYP51 (50 kDa) also resides on acrosomal membranes of bull- and ram-ejaculated sperm. In mouse liver, a 53-kDa CYP51 is no longer detected in trans Golgi, suggesting retrieval back to the ER and no further transport to other organelles. Glycosylated high-molecular-mass CYP51-immunoreactive proteins in acrosomal membranes of bull and ram and Golgi-enriched fractions of mouse liver indicate that mammalian CYP51s are subjected to posttranslational modifications in the Golgi. In conclusion, CYP51 is the first cytochrome P450 enzyme to be detected on acrosomal membranes. It exhibits a unique, cell-type-specific intracellular transport that is in agreement with its cell-type-specific physiological role: production of cholesterol in the liver and sterols with signaling properties in sperm. Demethylation of lanosterol to FF-MAS by the acrosomal lanosterol 14 alpha-demethylase enzyme complex demonstrates for the first time the ability of ejaculate sperm to synthesize meiosis-activating sterols.

Lanosterol 14alpha-demethylase and MAS sterols in mammalian gametogenesis.

The lanosterol 14alpha-demethylase protein complex is composed of a cytochrome P450 enzyme CYP51 and its redox partner NADPH cytochrome P450 reductase. The complex participates in cholesterol biosynthesis and produces folicular fluid meiosis activating sterol (FF-MAS) from lanosterol. FF-MAS is metabolized further by sterol Delta14-reductase to testis-meiosis activating sterol (T-MAS). Additional enzymatic steps are needed before cholesterol is produced. Using the anti-human CYP51 antibody we have studied CYP51 protein expression by confocal microscopy in male and female mouse gonads. Leydig cells and acrosomes of spermatids express the highest levels of the CYP51 protein. CYP51 protein is also detected in primary mouse oocytes of non-treated mice and in some granulosa cells. While regulatory mechanisms responsible for FF-MAS accumulation in the ovary are not yet established, two mechanisms contributing to production the of T-MAS in the testis have been found. Potential in vivo roles of FF-MAS and T-MAS in fertilization are discussed.

Study of impacts of treated wastewater to the Krka river, Slovenia.

Surface waters are used for disposal of treated effluents from wastewater treatment plants. These effluents usually contain only small amounts of various contaminants but these harmful components accumulate over time in the river, especially in sediments. An integrated approach for the evaluation of the impact of treated effluents was used to predict an ecological risk assessment to the Krka river beside Novo Mesto. The effluents from pharmaceutical and municipal wastewater treatment plants were discharged too closely into the receiving stream, so that separate impacts could not be distinguished. Biologically treated industrial effluents contained great amounts of barely biodegradable organic pollution, organic nitrogen, ammonia and phosphorus, and sometimes zinc. The toxicity of effluents was mostly dependent on their chemical composition. The municipal discharge contained greater amounts of organic pollution that was completely biodegraded but still had a great nutrient pollution load. The effluents were nontoxic. The harmful substances from the effluents were traced in the river. In the downstream site slightly higher concentration of organic pollutants, organic nitrogen, phosphorus, and zinc were detected due to discharges. The river water was over-saturated with oxygen, especially in the summer. In toxicity tests, samples of the river water were nontoxic. Sediments at the downstream site accumulated from discharged organic nitrogen, phosphorus, or zinc. The results of our study show that the main problem is eutrophication of the river Krka, so it is obvious we must reduce the quantity of nutrients in the effluents from wastewater treatment plants. In both effluents it will be necessary to reduce the polluting load of phosphorus, the limiting element for growth of algae and macrophytes in the receiving stream. In the industrial effluent it will be necessary to reduce substances which cause toxicity, such as zinc and nonbiodegradable organic compounds that may be accumulatec the water ecosystem over time.

Evaluation of total nitrogen pollution reduction strategies in a river basin: a case study.

The enrichment of groundwater and rivers by nutrients (nitrogen and phosphorus compounds) and their consequences is one of the most severe problems across Europe as well in Slovenia. Transfer of nutrients from different sources into the environment causes eutrophication of surface waters, nitrate accumulation in groundwater, and others. In this paper, the methodology of the material flow analysis is presented and applied to develop a nitrogen balance in a river basin and to evaluate different scenarios for total nitrogen pollution reduction. Application of the methodology is illustrated by means of a case study on the Krka river, Slovenia. Different scenarios are to be considered: the present level of sewerage and treatment capacities, different stages of wastewater treatment and management of agricultural activities on land. The results show that beside effluents from wastewater treatment plants, agriculture contributes significantly to the total annual nitrogen load. Beside reduction of point sources by means of wastewater collection and implementation of nutrient removal technology, managing agricultural nitrogen in order to protect river water quality and drinking water supply should become a major challenge in the Krka river basin.

Localisation of lanosterol 14alpha-demethylase in round and elongated spermatids of the mouse testis: an immunoelectron microscopic and stereological study.

Lanosterol 14alpha-demethylase (CYP51) is a microsomal cytochrome P450 enzyme involved in the postsqualene cholesterol biosynthetic pathway. CYP51 removes 14alpha-methyl group from lanosterol], forming FF-MAS (folicular fluid meiosis activating sterol) which accumulates in gonads. The goal of our study is to determine the expression of CYP51 protein in the male gonad. Using electron microscopic immunogold techniques, CYP51 is localised on inner and outer acrosomal membranes of male germ cells, the round and elongated spermatids. Significance of CYP51 localization on the acrosome which is a Golgi-derived organelle is not known, but we propose that CYP51-formed FF-MAS can function as a signalling sterol during fertilisation.

Biodegradation and toxicity of wastewater from industry producing mineral fibres for thermal insulation.

The water chemistry, toxicity, and biodegradation of wastewater from an industry producing mineral fibres for thermal insulation were studied. Values for COD, BOD5, suspended solids, and phenol exceeded permissible values for the wastewater discharged into a nearby river and acute toxicity was also detected. Consequently, the effluent should be treated in a municipal wastewater treatment plant so its ready biodegradability was investigated. We found that the wastewater was readily biodegradable, therefore we assume it can be treated in the wastewater treatment plant as the ratio of the wastewater flow rate and the minimal total inflow into the sewage treatment plant would be one to at least 30.