LTR Retrotransposons in Fungi

Transposable elements with long terminal direct repeats (LTR TEs) are one of the best studied groups of mobile elements. They are ubiquitous elements present in almost all eukaryotic genomes. Their number and state of conservation can be a highlight of genome dynamics. We searched all published fungal genomes for LTR-containing retrotransposons, including both complete, functional elements and remnant copies. We identified a total of over 66,000 elements, all of which belong to the Ty1/Copia or Ty3/Gypsy superfamilies. Most of the detected Gypsy elements represent Chromoviridae, i.e. they carry a chromodomain in the pol ORF. We analyzed our data from a genome-ecology perspective, looking at the abundance of various types of LTR TEs in individual genomes and at the highest-copy element from each genome. The TE content is very variable among the analyzed genomes. Some genomes are very scarce in LTR TEs (<50 elements), others demonstrate huge expansions (>8000 elements). The data shows that transposon expansions in fungi usually involve an increase both in the copy number of individual elements and in the number of element types. The majority of the highest-copy TEs from all genomes are Ty3/Gypsy transposons. Phylogenetic analysis of these elements suggests that TE expansions have appeared independently of each other, in distant genomes and at different taxonomical levels. We also analyzed the evolutionary relationships between protein domains encoded by the transposon pol ORF and we found that the protease is the fastest evolving domain whereas reverse transcriptase and RNase H evolve much slower and in correlation with each other

Drinking Water Quality: Temporary Deviations from Hygienic Standards

Introduction: Current legislation permits a phased achievement of drinking water quality standards by making decisions on temporary deviations from hygienic standards for the period of design, construction, and/or upgrade of water supply facilities. Objective: To substantiate the mechanism for coordinating temporary deviations of concentrations of certain chemicals in drinking water from hygienic standards for the period of implementing measures for water quality improvement. Materials and methods: We applied methods of sanitary and epidemiological expert examination and assessment and the method of system analysis to review and study current regulations, results of laboratory testing of water quality in centralized cold water supply systems for 2011–2019, and action plans of 83 constituent entities of the Russian Federation for improvement of tap water quality. Results: We established that violation of hygienic standards was most often registered for aluminum, boron, bromine, iron, silicon, lithium, magnesium, manganese, sodium, and chloroform. Hygienic requirements for tap water quality determine necessary technological solutions to be implemented at water treatment facilities; yet, their implementation requires a certain amount of time and might cause temporary tap water quality deterioration making it necessary to agree with the local bodies in charge of federal sanitary and epidemiological surveillance a phased transition to eliminating threat to public health from poor quality drinking water. Conclusions: The authors propose an algorithm for conducting a risk assessment and a mechanism for decision making on temporary deviations.</jats:p

Production Control as a Component of Drinking Water Quality Monitoring

Summary. Introduction: In order to conduct a more precise and objective assessment of drinking water quality in the centralized cold water supply systems, it is essential to increase the coverage of population with laboratory control. It is therefore expedient to consider the possibility of using production control data collected within the drinking water quality monitoring system and including them in statistical reporting forms of Rospotrebnadzor for subsequent accounting when assessing the implementation of the Russian Federal Clean Water Project within the National Ecology Project. Our objective was to substantiate requirements for organization of production control of drinking water with considering a further use of its results in assessing drinking water quality. The materials of the research included current regulations and literature data. We applied methods of sanitary and epidemiologic expert examination, assessment and survey as well as methods of systemic and content analysis. Results: To evaluate the supply of the population with high-quality drinking water, it is important to consider not only test results collected within the framework of the federal state sanitary and epidemiologic surveillance but also the results of production control carried out by legal entities and individual entrepreneurs operating centralized cold water supply systems. However, organization of production control and the use of its results is usually associated with such problems as the choice of the most representative sampling points, identification of a sufficient list of controlled indicators, quality of results, etc. Conclusions: Before including the results of drinking water quality production control in the drinking water quality monitoring system, it is necessary to set the requirements for selecting monitoring sites, analytes, frequency of testing, etc. To legitimize the use of production control results, it is important to develop regulations that oblige organizations carrying out production control of drinking water quality to submit their results to Rospotrebnadzor bodies and institutions for their use in comprehensive drinking water quality assessments.</jats:p