Some problems and errors in cytogenetic biodosimetry

Human radiosensitivity is a quantitative trait that is generally subject to binomial distribution. Individual radiosensitivity, however, may deviate significantly from the mean (by 2-3 standard deviations). Thus, the same dose of radiation may result in different levels of genotoxic damage (commonly measured as chromosome aberration rates) in different individuals. There is significant genetic component in individual radiosensitivity. It is related to carriership of variant alleles of various single-nucleotide polymorphisms (most of these in genes coding for proteins functioning in DNA damage identification and repair); carriership of different number of alleles producing cumulative effects; amplification of gene copies coding for proteins responsible for radioresistance, mobile genetic elements, and others. Among the other factors influencing individual radioresistance are: radioadaptive response; bystander effect; levels of endogenous substances with radioprotective and antimutagenic properties and environmental factors such as lifestyle and diet, physical activity, psychoemotional state, hormonal state, certain drugs, infections and others. These factors may have radioprotective or sensibilising effects. Apparently, there are too many factors that may significantly modulate the biological effects of ionising radiation. Thus, conventional methodologies for biodosimetry (specifically, cytogenetic methods) may produce significant errors if personal traits that may affect radioresistance are not accounted for

Theoretical aspects of heterosis

The phenomenon of heterosis, known as superior performance of hybrid organism compared with either of their parents, has been exploited by agricultural practices in the production of various crops since the beginning of the last century; however, its genetic basis has remained obscure. With experimental data obtained from the study of maize hybrids, and mathematical calculations, some genetic models have been proposed to explain heterosis from various types of gene interaction, such as dominance, over-dominance and epistasis. However, any of the proposed concepts has weak points, which place limitations on the possibility of overall interpretation of heterotic response in F1. In this review we gather a brief account of findings from various studies for critical evaluation of the main theoretical concepts based on the information accumulated to date by genetics and molecular biology and focused on particular mechanisms acting for specific traits. We discussed some aspects concerning the role of mutation loads in the formation of heterotic phenotype. Also, we gathered a brief account of findings for interpretation of genetic effects due to linkage and non-allelic genes’ interactions that make nuances to analysis of dominance and over-dominance. We have provided information about combining ability, its practical application in the context of the concept of heterotic groups. Here we also discussed some aspects of “genotype–environment” interaction. Recent advancements in genetics and molecular biology indicate the importance of various types of gene action for heterosis and confirm the necessity of systemlevel approaches to understanding this unique phenomenon

Mineral composition of bread wheat lines with introgressions of alien genetic material

Background. Modern bread wheat (Triticum aestivum L.) cultivars developed mainly to increase productivity often contain low concentrations of minerals in their grain. Wild and primitive wheats demonstrate rich genetic diversity, including the content of minerals in the grain, and can be used to improve the wheat gene pool for this trait. The aim of this work was to study the mineral composition in the grain of bread wheat lines with introgressions of the genetic material from Triticum L. spp.Materials and methods. We studied parental spring bread wheat cultivars, accessions of tetraploid and hexaploid Triticum spp., and 20 introgressive lines obtained on their basis in 2018 and 2020. Concentrations of macro- (K, P, Ca, and Mg) and micronutrients (Zn, Fe, Cu, and Mn) were measured using atomic emission spectrometry with inductively coupled plasma, and total protein content in wheat grain according to GOST 10846-91. The data were processed using the Statistica 10.0 and MS Excel software packages.Results and conclusion. The content of minerals in the grain of Triticum spp. was higher than in T. aestivum cultivars (the twoyear average difference was 1,02 to 2,13-fold, depending on the studied mineral). Most of the lines with alien genetic material exceeded their parent bread wheat cultivars in Zn, Fe, Cu and Mn content and came close to them in the levels of N, P, Mg and K. ANOVA established a statistically significant impact of the genotype, environment, and genotype × environment interaction on the variation of the grain macro- and micronutrient content. Lines with a consistently high concentration of grain minerals and high productivity were identified. These lines are of interest for wheat breeding for grain quality

SSR loci potentially associated with high amylopectine content in maize kernel endosperm

As a component of functional nutrition, maize cultivars with “non-traditional” kernel composition (waxy, oilbearing, sugar, opaque, etc. phenotypic variants) are promising. Mutations in the waxy gene, which break down the structure and function of the enzyme for amylose biosynthesis, lead to a waxy (with a high content of amylopectin) endosperm formation. High variability of the waxy gene limits the use of microsatellite loci in marker associated selection of waxy maize genotypes. The increased frequency of gene rearrangements within the waxy locus facilitated the origination of many high-amylopectin corn lines carrying different SSR allelic variants. The purpose of this study was to evaluate the effectiveness of using waxy locus microsatellite sequences for identification and labeling of waxy maize genotypes. To this end, a complex of biochemical (calorimetry, bichromate method), molecular-genetic (SSR-PCR, capillary gel electrophoresis with fluorescent detection of fragments) and statistical (descriptive statistics, cluster analysis, χ2) analysis methods was used. Plant material used were 33 samples of corn kernels including mutant forms with a high content of amylose, amylopectin, short-chain starches, were kindly provided by VIR genetic collection (Russian Federation) and Maize Genetics Cooperation Stock Center (USA). The contents of starch, short-chain soluble carbohydrates, amylose, amylopectin in the grain of 33 maize samples were evaluated. Compositionally similar (to endosperm carbohydrates content) groups of samples were identified. They include 13 high-amylopectin samples carriers of waxy (wx) gene mutations and 20 samples with wild-type character (Wx). Molecular genetic screening of the collection included an analysis of the polymorphism of the microsatellite loci phi022, phi027, phi061 associated with the waxy gene sequence. Allelic composition of individual loci and their combinations were analyzed in relation to the accumulation of reserve carbohydrates in the kernel endosperm. Only the analysis of the phi022/phi027 combination or all three markers in the complex allows differentiating the wild Wx and mutant wx phenotypes of maize. It was shown that not the individual allelic polymorphisms of the phi022, phi027, phi061 loci are efficient for the markerassociated selection of high-amylopectin maize, but their unique combinations

Composition of high-molecular-weight glutenin subunits and gluten quality in wheat lines with alien genetic material

Background. High-molecular-weight glutenin subunits (HMW-GSs) make the greatest contribution to the formation of baking properties in bread wheat (Triticum aestivum L.). Glutenin polymorphism of bread wheat relatives is significantly richer than in cultivated varieties. The objective of this work was to identify the HMW-GS composition and assess the gluten quality of bread wheat lines with introgressions of alien genetic material.Materials and methods. We studied the parental varieties of spring bread wheat, accessions of the tetraploid and hexaploid Triticum L. species, and 19 introgressive lines produced with their participation. Glutenins were separated using sodium dodecyl sulfate polyacrylamide gel electrophoresis and HMW-GSs were identified using the Payne nomenclature system. Gluten quality was determined in accordance with GOST 13586.1-68 (the 2017–2019 and 2021–2022 growing seasons). Data processing was performed using the Statistica 10.0 and MS Excel software packages.Results and conclusion. HMW-GSs uncharacteristic of T. aestivum cultivars were identified in the studied accessions of T. dicoccoides (Körn. ex Aschers. et Graebn.) Schweinf., T. spelta L., and T. kiharae Dorof. et Migusch. These HMW-GSs are of interest for enriching the wheat gene pool. HMW-GSs of related species were found in 10 out of 19 introgressive lines. A five-year observation period revealed that wheat relatives on average significantly exceeded common wheat cultivars in gluten quality, and introgressive lines did not differ significantly from the parental genotypes. Lines with high rheological properties of gluten had, as a rule, HMW-GSs of related species in their composition

Marker-assisted identification of maize genotypes with improved protein quality

Currently, more than 70 % of maize is used for food and fodder; therefore, grain quality improvement can increase its nutritive and energy value. Deficiency of two essential amino acids (lysine and tryptophan) significantly reduces the nutritional quality of maize proteins. However, in comparison to conventional maize varieties, opaque2 (o2) mutants have greater contents of lysine and tryptophan in their endosperm proteins and their bioavailability is better. The aim of the study was identification of maize accessions with high-quality protein. A collection of maize accessions of various ecogeographical origins was studied by molecular methods. This approach was expected to improve maize breeding efficiency. We collected 54 maize genotypes differing in grain quality performance. Amplification with three specific markers to the opaque-2 gene (phi057, phi112 and umc1066) revealed homozygous recessive o2 genotypes, associated with improved nutritional quality of the protein. UREA-PAG electrophoresis of zein proteins was used for Quality Protein Maize (QPM) identification. In addition to the mutant o2 allele, QPM contains genetic modifiers that convert starchy endosperm of o2 mutant to the hard vitreous phenotype. The selected QPM accessions are of interest for maize breeding programs aimed at grain quality improvement. The use of the markers to o2 and modifier genes accelerates the development of QPM varieties and significantly reduces the labor and financial costs of their production

Molecular-genetic mechanisms underlying fruit and seed coloration in plants

Diverse patterns of plant fruit and seed coloration are determined by the presence of two main types of pigment, carotenoids (red, orange and yellow color) and anthocyanins (purple, blue, red). Thеy belong to two groups of secondary metabolites, isoprenoids and flavonoids. Interest towards the genetic mechanisms that control coloration in plants has recently increased due to the antioxidant and antimicrobial properties of some pigments and their colorless precursors consumed with plant-derived food. The genes encoding enzymes involved in step-bystep conversion of initial organic molecules to final pigmented compounds are referred to as structural genes, while regulatory genes are responsible for activation of the expression of structural genes and control the synthesis of pigments at certain times and in proper tissue. The data in plant genetics accumulated to date show that the inter- and intraspecies phenotypic diversity in coloration is mainly related with regulatory genes. Previously developed rich gene collections and precise genetic models for coloration traits in dicots and monocots as well as the rapid development of molecular genetic methods for studying plants allowed for studying genetic regulation of pigment synthesis at a molecular level. The peculiarities of the regulation of carotenoid biosynthesis are exemplified with Solanaceae fruits. The genetic mechanisms underlying the synthesis of various flavonoid pigments are exemplified with a study of seed color in Poaceae plants. In summary, prospects for the practical use of regulatory genes that control pigment synthesis are discussed and examples of their practical use in vegetable and cereal crop breeding are given

ИДЕНТИФИКАЦИЯ ГЕНОВ, КОДИРУЮЩИХ СТРЕСС-АССОЦИИРОВАННЫЕ БЕЛКИ, СОДЕРЖАЩИЕ ДОМЕНЫ A20/AN1, В ГЕНОМЕ ЯБЛОНИ IN SILICO И АНАЛИЗ ИХ ФИЛОГЕНЕТИЧЕСКИХ СВЯЗЕЙ

Stress-associated proteins (SAPs) are the transcription factors containing the zinc-finger domains A20 and/or AN1. Genome-wide identification and characterization of an apple variety of Golden Delicious stress-associated proteins was performed, potential SAPs were found. Each of them contains, at least, one zinc-finger domain AN1. A phylogenetic tree was constructed on the basis of the amino acid sequences of apple SAP and homologues from other species (dicotyledonous cotton and monocotyledonous rice) to assess their phylogenetic relationships. The sequences ahead of the translation initiation site of SAPs genes were analyzed to discover cis-elements involved in the gene expression regulation. The analysis shows that apple SAPs are involved in a complex network of regulatory elements that controls the vitality of plant cells. It can be assumed that the expression of SAPs in apple trees occurs constantly, but if conditions of a plant growth are changed, their level increases. Regulation of the SAP expression may depend on a plant ontogenesis stage and it may vary in different tissues.Стресс-ассоциированные белки (SAP, от англ. stress-associated proteins) представляют собой транскрипционные факторы с цинковыми пальцами, содержащие домены A20 и (или) AN1. В геноме яблони домашней сорта Golden Delicious выявлены гены, кодирующие гипотетические SAP. Каждый из них содержит как минимум один домен цинковых пальцев AN1. Проведена оценка филогенетических взаимоотношений гипотетических SAP из генома яблони с гомологами из других видов (на примере двудольного хлопчатника и однодольного риса) на основании их аминокислотных последовательностей. Aнализ нуклеотидной структуры регионов, расположенных перед генами, кодирующими SAP, свидетельствует о вовлеченности стресс-ассоциированных белков в сложную сеть взаимодействия регуляторных белков, управляющих жизнедеятельностью растительных клеток. Исходя из выявленных мотивов, можно предположить, что экспрессия стресс-ассоциированных белков у яблони происходит, вероятнее всего, непрерывно, однако изменения условий произрастания растения могут приводить к увеличению ее уровня. Регуляция экспрессии SAP может меняться в зависимости от стадии онтогенеза растения и отличаться в разных его органах. Об этом свидетельствует наличие сайтов связывания для транскрипционных факторов, участвующих в формировании органов растения, определении времени прохождения стадий онтогенеза и др. Наличие сайтов связывания для регуляторных элементов, влияющих на устойчивость растений к неблагоприятным условиям, позволяет предполагать, что экспрессия SAP у яблони, так же, как и у других изученных растений, будет изменяться в ответ на стресс

Some aspects of gene association with high sport achievements

Most papers on sport genetics identify differences between genotypes of athletes and a control group. It is obvious that the genetic differences should also be among sportsmen with different qualifications. Additionally, athletes’ performance depends not only on their genotypes, but also on the gene activities, which can be different during the training process in various athletes.The aim of the study was to compare genotypes of athletes with different qualifications and to analyze the change in expression of some genes responsible for the physical performance. Genotypes of 143 elite sportsmen of 18 national teams were analyzed by PCR method. A comparison of the genotypes of Masters of Sports, International Masters of Sports and Honored Masters of Sports showed that the frequencies of favorable gene variants were higher in the genotypes of more qualified athletes; it proves an appropriate genetic potential necessity for high achievements in sports. The analysis of UCP2, HIF1A and MTHFR gene expression changes in response to two-week hypoxiс training was performed on 15 skaters of high qualification. We found that average UCP2 and MTHFR mRNA levels had significantly increased after the training but the expression of the HIF1A gene had reduced. At the same time, individual athlete variability in UCP2, HIF1A and MTHFR gene expression was revealed. Genotype influence on gene expression was shown with the help of the UCP2 gene – its activity was higher in sportsmen with Val/Val than with Val/Ala or Ala/Ala genotypes. Consequently, genotyping and analysis of gene expression is very important for athlete selection and training

A Case of In-Bore Transperineal MRI-Guided Prostate Biopsy of a Patient with Ileal Pouch-Anal Anastomosis

Ulcerative colitis (UC) is an inflammatory disease that specifically affects the colon. Ulcerative colitis is primarily treated medically and refractory disease is treated with proctocolectomy and ileal pouch-anal anastomosis (IPAA). Gastroenterologists advise against digital rectal exams, pelvic radiation therapy, and transrectal ultrasound (TRUS) biopsies of the prostates of ileal pouch-anal anastomosis patients. Any form of pouch manipulation can lead to severe bleeding, inflammation, and pain. Urologists are therefore faced with the challenge of doing a prostate biopsy without a transrectal ultrasound. We report the rare case of a patient with an ileal pouch-anal anastomosis who underwent in-bore transperineal MRI-guided biopsy of the prostate