Characteristics of dr1790 disruptant and its functional analysis in Deinococcus radiodurans

Deinococcus radiodurans (DR) is an extremophile that is well known for its resistance to radiation, oxidants and desiccation. The gene dr1790 of D. radiodurans was predicted to encode a yellow-related protein. The primary objective of the present study was to characterize the biological function of the DR1790 protein, which is a member of the ancient yellow/major royal jelly (MRJ) protein family, in prokaryotes. Fluorescence labeling demonstrated that the yellow-related protein encoded by dr1790 is a membrane protein. The deletion of the dr1790 gene decreased the cell growth rate and sensitivity to hydrogen peroxide and radiation and increased the membrane permeability of D. radiodurans. Transcript profiling by microarray and RT-PCR analyses of the dr1790 deletion mutant suggested that some genes that are involved in protein secretion and transport were strongly suppressed, while other genes that are involved in protein quality control, such as chaperones and proteases, were induced. In addition, the expression of genes with predicted functions that are involved in antioxidant systems, electron transport, and energy metabolism was significantly altered through the disruption of dr1790. Moreover, the results of proteomic analyses using 2-DE and MS also demonstrated that DR1790 contributed to D. radiodurans survival. Taken together, these results indicate that the DR1790 protein from the ancient yellow protein family plays a pleiotropic role in the survival of prokaryotic cells and contributes to the extraordinary resistance of D. radiodurans against oxidative and radiation stresses.

Pleiotropic effects of the sdw1 locus in barley populations representing different rounds of recombination

Background In the present study populations, representing different rounds of recombination were used for the analysis of phenotypic effects associated with the sdw1/denso locus. Other studies have mostly focused only on one type of population. Many different QTLs mapped at the same position as the sdw1/denso locus may indicate a pleiotropy of this gene or a tight linkage between genes conditioning quantitative traits. To date, results of studies have not unequivocally proven either of these two phenomena. Results Both breeding and molecular mapping experiments were undertaken to examine 200 single seed descent (SSD) and 60 doubled haploid (DH) lines obtained from the Maresi (with a semi-dwarfing gene) and Pomo cross combination. They were evaluated for the type of juvenile growth habit and certain agronomic traits were measured after harvesting. The estimates of mean values, standard errors and significance of effects were analyzed. In terms of the analyzed characteristics, the greatest variability was obtained for genotypes with the prostrate growth habit. Microsatellite markers (SSR) were also used to identify co-segregation with the sdw1/denso locus and Bmag0013, Bmag0877, Bmag0306b markers were linked the closest. A partial linkage map of chromosome 3H with the sdw1/denso semi-dwarfing gene was constructed and QTLs were identified. Conclusions Our experiments confirmed the impact of the semi-dwarfing gene on plant height, heading and flowering date both in SSD and DH populations, which may indicate pleiotropy. Moreover, a partial linkage between sdw1/denso locus and grain weight per spike and 1000-grain weight was found in the SSD population.

Análise genética de fenótipos cardiometabólicos complexos em população urbana e rural de Minas Gerais / The cardiometabolic phenotypes with different strategies of genetic analyses using the estimate of heritability in an urban area, in Minas Gerais

Fenótipos cardiometabólicos como doenças cardiovasculares, obesidade, resistência à insulina, diabetes, alteração nos níveis lipídicos são responsáveis por elevada mortalidade e outras complicações. A predisposição genética influencia diversos aspectos do metabolismo que elevam o risco, e, consequentemente, contribui para o aumento da prevalência desses fenótipos, sendo uma das áreas promissoras na descoberta da etiogênese das doenças crônicas. Portanto, o objetivo do estudo foi investigar potenciais associações genéticas - utilizando diferentes estratégias de análise - com fenótipos cardiometabólicos por meio da estimativa da herdabilidade em população rural e da estimativa de ocorrência do polimorfismo do receptor de leptina (LEPR) Gln223Arg em população urbana, ambas em Minas Gerais. Para tal, foram utilizados dois estudos transversais. O primeiro foi realizado nas áreas rurais de Virgem das Graças, Caju e São Pedro do Jequitinhonha, no qual 931 indivíduos pertencentes a 89 pedigrees foram fenotipados. Nesse estudo foi utilizada a estratégia de estimativa de herdabilidade (h2), correlações genéticas e ambientais e sua associação com níveis lipídicos, índice de massa corporal, circunferência abdominal e pressão arterial. No segundo estudo foi utilizada a avaliação da frequência do polimorfismo do LEPR Gln223Arg e potenciais associações com sobrepeso, obesidade, obesidade abdominal e gordura corporal. As estimativas de h2 para os fenótipos avaliados variaram de 28 a 60%, e correlações genéticas (ρg) significativas foram encontradas para a maioria dos pares de fenótipos avaliados (considerando os modelos ajustados): triglicérides - VLDL (ρg=0,99), colesterol total - LDL (ρg=0,90), pressão arterial diastólica - triglicérides (ρg=0,63), pressão arterial diastólica - VLDL (ρg=0,59), além do triglicérides-colesterol total (ρg=0,58). De forma geral, as correlações genéticas foram superiores às correlações ambientais. Foram encontrados efeito household...

Cardiometabolic phenotypes such as cardiovascular diseases, obesity, insulin resistance, diabetes, high level of lipids were responsible for high mortality and its complications. Genetics could influence metabolism in many aspects and it could contribute to the high prevalence of these phenotypes. Therefore, the objective of this study was to research the cardiometabolic phenotypes with different strategies of genetic analyses using the estimate of heritability in a rural area, in Vale do Jequitinhonha and to associate the leptin receptor polymorphism (LEPR) Gln223Arg in an urban area, in Minas Gerais. Both studies were cross-sectional. The first study was conducted in the rural area of Virgem das Graças, Caju and São Pedro do Jequitinhonha, in which 931 individuals of 89 pedigrees were phenotyped. In the first study, the strategy of estimating heritability (h2), pleiotropy and its association with lipid levels, body mass index, waist circumference and blood pressure was evaluated. In the second study, the frequency of the LEPR Gln223Arg and the potentials associations with overweight, obesity, abdominal obesity and higher body fat was evaluated. The h2 estimates for the phenotypes evaluated ranged 28 to 60% and significant genetic correlations (ρg) were found for most pairs of phenotypes evaluated mainly among triglycerides - VLDL (ρg = 0.99), total cholesterol - LDL (ρg = 0.90), diastolic blood pressure - triglycerides (ρg = 0.63) and diastolic blood pressure - VLDL (ρg = 0.59), total cholesterol - triglycerides (ρg = 0.58). In general, genetic correlations were higher than the environmental correlations. Household effects have been found for HDL (c2 = 0.21, P < 0.001) and VLDL (c2 = 0.10, P = 0.010) and hypertension (c2 = 0.14, P = 0.015). Finally, to complete pleiotropy found between VLDL - triglycerides, it means that these phenotypes are controlled by a single gene or by a set of genes. Moreover, in the urban area, high levels of...