Genetic parameters controlling the inheritance of glaucousness and yield traits in bread wheat / Parâmetros genéticos que controlam a herança de glaucosidade e características de produção em trigo mole

Wheat breeders frequently use generation mean analysis to obtain information on the type of gene action involved in inheriting a trait to choose the helpful breeding procedure for trait improvement. The present study was carried out to study the inter-allelic and intra-allelic gene action and inheritance of glaucousness, earliness and yield traits in a bread wheat cross between divergent parents in glaucousness and yield traits; namely Mut-2 (P1) and Sakha 93 (P2). The experimental material included six populations, i.e. P1, P2, F1, F2, BC1, and BC2 for this wheat cross. A randomized complete block design with three replications was used, and a six parameters model was applied. Additive effects were generally more critical than dominance for all studied traits, except for plant height (PH) and grain yield/plant (GYPP). The duplicate epistasis was observed in spike length; SL, spikes/plant; SPP and days to heading; DTH. All six types of allelic and non-allelic interaction effects controlled SL, GYPP, DTH and glaucousness. All three types of epistasis, i.e. additive x additive, additive x dominance, and dominance x dominance, are essential in determining the inheritance of four traits (SL, GYPP, DTH and glaucousness). Dominance × dominance effects were higher in magnitude than additive × dominance and additive × additive in most traits. The average degree of dominance was minor than unity in six traits (glaucousness, grains/spike, spike weight, days to maturity, 100-grain weight and SL), indicating partial dominance and selection for these traits might be more effective in early generations. Meanwhile, the remaining traits (PH, SPP, GYPP and DTH) had a degree of dominance more than unity, indicating that overdominance gene effects control such traits and it is preferable to postpone selection to later generations. The highest values of [...].

Os criadores de trigo frequentemente usam a análise da média de geração para obter informações sobre o tipo de ação do gene envolvida na herança de uma característica para escolher o procedimento de melhoramento útil para o aprimoramento da característica. O presente estudo foi conduzido para estudar a ação do gene interalélico e intraalélico e a herança de características de glaucosidade, precocidade e produção em um cruzamento de trigo mole entre pais divergentes em glaucosidade e características de produção; nomeadamente Mut-2 (P1) e Sakha 93 (P2). O material experimental incluiu seis populações, ou seja, P1, P2, F1, F2, BC1 e BC2 para este cruzamento de trigo. O delineamento experimental foi em blocos ao acaso com três repetições e aplicado um modelo de seis parâmetros. Os efeitos aditivos foram geralmente mais críticos do que a dominância para todas as características estudadas, exceto para altura da planta (AP) e rendimento de grãos / planta (GYPP). A epistasia duplicada foi observada no comprimento da ponta; SL, espigas / planta; SPP e dias para o cabeçalho; DTH. Todos os seis tipos de efeitos de interação alélica e não alélica controlaram SL, GYPP, DTH e glaucosidade. Todos os três tipos de epistasia, ou seja, aditivo x aditivo, aditivo x dominância e dominância x dominância, são essenciais na determinação da herança de quatro características (SL, GYPP, DTH e glaucosidade). Os efeitos de dominância × dominância foram maiores em magnitude do que aditivo × dominância e aditivo × aditivo na maioria das características. O grau médio de dominância foi menor do que a unidade em seis características (glaucosidade, grãos / espiga, peso da espiga, dias até a maturidade, peso de 100 grãos e SL), indicando dominância parcial, e a seleção para essas características pode ser mais eficaz nas gerações iniciais. Enquanto isso, os traços restantes (PH, SPP, GYPP e [...].

Genetic parameters controlling the inheritance of glaucousness and yield traits in bread wheat

Abstract Wheat breeders frequently use generation mean analysis to obtain information on the type of gene action involved in inheriting a trait to choose the helpful breeding procedure for trait improvement. The present study was carried out to study the inter-allelic and intra-allelic gene action and inheritance of glaucousness, earliness and yield traits in a bread wheat cross between divergent parents in glaucousness and yield traits; namely Mut-2 (P1) and Sakha 93 (P2). The experimental material included six populations, i.e. P1, P2, F1, F2, BC1, and BC2 for this wheat cross. A randomized complete block design with three replications was used, and a six parameters model was applied. Additive effects were generally more critical than dominance for all studied traits, except for plant height (PH) and grain yield/plant (GYPP). The duplicate epistasis was observed in spike length; SL, spikes/plant; SPP and days to heading; DTH. All six types of allelic and non-allelic interaction effects controlled SL, GYPP, DTH and glaucousness. All three types of epistasis, i.e. additive x additive, additive x dominance, and dominance x dominance, are essential in determining the inheritance of four traits (SL, GYPP, DTH and glaucousness). Dominance × dominance effects were higher in magnitude than additive × dominance and additive × additive in most traits. The average degree of dominance was minor than unity in six traits (glaucousness, grains/spike, spike weight, days to maturity, 100-grain weight and SL), indicating partial dominance and selection for these traits might be more effective in early generations. Meanwhile, the remaining traits (PH, SPP, GYPP and DTH) had a degree of dominance more than unity, indicating that overdominance gene effects control such traits and it is preferable to postpone selection to later generations. The highest values of narrow-sense heritability and genetic advance were recorded by glaucousness trait followed by SL and SPP, indicating that selection in segregating generations would be more effective than other traits.

Resumo Os criadores de trigo frequentemente usam a análise da média de geração para obter informações sobre o tipo de ação do gene envolvida na herança de uma característica para escolher o procedimento de melhoramento útil para o aprimoramento da característica. O presente estudo foi conduzido para estudar a ação do gene interalélico e intraalélico e a herança de características de glaucosidade, precocidade e produção em um cruzamento de trigo mole entre pais divergentes em glaucosidade e características de produção; nomeadamente Mut-2 (P1) e Sakha 93 (P2). O material experimental incluiu seis populações, ou seja, P1, P2, F1, F2, BC1 e BC2 para este cruzamento de trigo. O delineamento experimental foi em blocos ao acaso com três repetições e aplicado um modelo de seis parâmetros. Os efeitos aditivos foram geralmente mais críticos do que a dominância para todas as características estudadas, exceto para altura da planta (AP) e rendimento de grãos / planta (GYPP). A epistasia duplicada foi observada no comprimento da ponta; SL, espigas/planta; SPP e dias para o cabeçalho; DTH. Todos os seis tipos de efeitos de interação alélica e não alélica controlaram SL, GYPP, DTH e glaucosidade. Todos os três tipos de epistasia, ou seja, aditivo x aditivo, aditivo x dominância e dominância x dominância, são essenciais na determinação da herança de quatro características (SL, GYPP, DTH e glaucosidade). Os efeitos de dominância × dominância foram maiores em magnitude do que aditivo × dominância e aditivo × aditivo na maioria das características. O grau médio de dominância foi menor do que a unidade em seis características (glaucosidade, grãos / espiga, peso da espiga, dias até a maturidade, peso de 100 grãos e SL), indicando dominância parcial, e a seleção para essas características pode ser mais eficaz nas gerações iniciais. Enquanto isso, os traços restantes (PH, SPP, GYPP e DTH) tiveram um grau de dominância maior do que a unidade, indicando que os efeitos do gene de superdominância controlam tais traços e é preferível adiar a seleção para gerações posteriores. Os maiores valores de herdabilidade no sentido restrito e avanço genético foram registrados pelo traço de glaucosidade seguido por SL e SPP, indicando que a seleção em gerações segregadas seria mais eficaz do que outros caracteres.

Genetic parameters controlling the inheritance of glaucousness and yield traits in bread wheat / Parâmetros genéticos que controlam a herança de glaucosidade e características de produção em trigo mole

Wheat breeders frequently use generation mean analysis to obtain information on the type of gene action involved in inheriting a trait to choose the helpful breeding procedure for trait improvement. The present study was carried out to study the inter-allelic and intra-allelic gene action and inheritance of glaucousness, earliness and yield traits in a bread wheat cross between divergent parents in glaucousness and yield traits; namely Mut-2 (P1) and Sakha 93 (P2).The experimental material included six populations, i.e. P1, P2, F1, F2, BC1, and BC2 for this wheat cross. A randomized complete block design with three replications was used, and a six parameters model was applied. Additive effects were generally more critical than dominance for all studied traits, except for plant height (PH) and grain yield/plant (GYPP). The duplicate epistasis was observed in spike length; SL, spikes/plant; SPP and days to heading; DTH. All six types of allelic and non-allelic interaction effects controlled SL, GYPP, DTH and glaucousness. All three types of epistasis, i.e. additive x additive, additive x dominance, and dominance x dominance, are essential in determining the inheritance of four traits (SL, GYPP, DTH and glaucousness). Dominance × dominance effects were higher in magnitude than additive × dominance and additive × additive in most traits. The average degree of dominance was minor than unity in six traits (glaucousness, grains/spike, spike weight, days to maturity, 100-grain weight and SL), indicating partial dominance and selection for these traits might be more effective in early generations. Meanwhile, the remaining traits (PH, SPP, GYPP and DTH) had a degree of dominance more than unity, indicating that overdominance gene effects control such traits and it is preferable to postpone selection to later generations. The highest values of narrow-sense heritability and genetic advance were recorded by glaucousness trait followed by SL and SPP, indicating that selection in segregating generations would be more effective than other traits.

Os criadores de trigo frequentemente usam a análise da média de geração para obter informações sobre o tipo de ação do gene envolvida na herança de uma característica para escolher o procedimento de melhoramento útil para o aprimoramento da característica. O presente estudo foi conduzido para estudar a ação do gene interalélico e intraalélico e a herança de características de glaucosidade, precocidade e produção em um cruzamento de trigo mole entre pais divergentes em glaucosidade e características de produção; nomeadamente Mut-2 (P1) e Sakha 93 (P2). O material experimental incluiu seis populações, ou seja, P1, P2, F1, F2, BC1 e BC2 para este cruzamento de trigo. O delineamento experimental foi em blocos ao acaso com três repetições e aplicado um modelo de seis parâmetros. Os efeitos aditivos foram geralmente mais críticos do que a dominância para todas as características estudadas, exceto para altura da planta (AP) e rendimento de grãos / planta (GYPP). A epistasia duplicada foi observada no comprimento da ponta; SL, espigas/planta; SPP e dias para o cabeçalho; DTH. Todos os seis tipos de efeitos de interação alélica e não alélica controlaram SL, GYPP, DTH e glaucosidade. Todos os três tipos de epistasia, ou seja, aditivo x aditivo, aditivo x dominância e dominância x dominância, são essenciais na determinação da herança de quatro características (SL, GYPP, DTH e glaucosidade). Os efeitos de dominância × dominância foram maiores em magnitude do que aditivo × dominância e aditivo × aditivo na maioria das características. O grau médio de dominância foi menor do que a unidade em seis características (glaucosidade, grãos / espiga, peso da espiga, dias até a maturidade, peso de 100 grãos e SL), indicando dominância parcial, e a seleção para essas características pode ser mais eficaz nas gerações iniciais. Enquanto isso, os traços restantes (PH, SPP, GYPP e DTH) tiveram um grau de dominância maior do que a unidade, indicando que os efeitos do gene de superdominância controlam tais traços e é preferível adiar a seleção para gerações posteriores. Os maiores valores de herdabilidade no sentido restrito e avanço genético foram registrados pelo traço de glaucosidade seguido por SL e SPP, indicando que a seleção em gerações segregadas seria mais eficaz do que outros caracteres.

Genetic characterization of maize doubled haploid lines for Fusarium stalk rot caused by Fusarium verticillioides

Fusarium stalk rot disease (FSR) of maize caused by Fusarium verticillioides (Sacc.) Nirenberg is becoming an important biotic production constraint in many of the major maize growing areas causing substantial yield losses. Inbreds are preferred as parents in hybrid development owing to homozygous nature and high heterotic ability. Double haploid (DH) technology has emerged as a significant milestone. A total of 339 DH lines were generated from two inbred lines, VL1043 (susceptible) and CM212 (resistant), through in vivo haploid induction method. The 339 DH lines along with parents were phenotyped for their response to the FSR at the College of Agriculture, V. C. Farm, Mandya, India during summer, kharif and rabi seasons of the 2019–2020. Best linear unbiased predictors (BLUPs) were estimated for the FSR disease scores over three seasons. A wide range of BLUP scores of three to nine indicated the presence of higher variation for response of DH lines to FSR disease. The higher estimates of standardized range (1.31) and phenotypic coefficient of variation (19.80) also displayed higher variability. Nine lines were moderately resistant and 188 exhibited moderately susceptible reaction. The distribution of DH lines was positively skewed (1.34) and platykurtic (2.31) which suggested complementary epistasis and involvement of large number of genes in the disease expression.

Determination of gene action for yield and its related traits in soybean under North-Western Himalayas conditions of India

Aim: To understand the nature and magnitude of gene action for yield and its related traits in soybean.Methodology: Fifty four triple test cross progenies developed by crossing 18 lines with three testers Him soya and Hara soya (P1 and P2) and their F1s were used as testers ‘L1’,’L2’ and ‘L3’. F1 seeds were produced by crossing Him soya with Hara soya during kharif 2011. By crossing these three testers with 18 lines (females), 54 triple test cross hybrids were developed during kharif 2012. The fifty four F1 hybrids along with 18 lines and 3 testers were sown during kharif 2013 in a randomized block design with three replications. Results: In the triple test cross progenies, sufficient genetic variations were found for all the traits, except petiole length. Epistasis was observed to be an integral part of genetic variations for traits like plant height, branches per plant, nodes on main stem, internode length, pods per plant, pod length, biological yield per plant, seed yield per plant, oil content, crude protein content. Epistatic interaction for most traits was additive x dominance and dominance x dominance (j+l) type. In addition to additive x dominance and dominance x dominance (j+l), additive x additive (i) type epistasis was observed for plant height, internode length, pods per plant and biological yield per plant. For the inheritance of most traits, fixable type of gene action was found as additive component (D), was more pronounced than dominance component (H), except pod length. Interpretation: For improvement of traits, selection in the early generations will be useful as additive gene action was observed. The importance of additive x dominance (j) and dominance x dominance (l) type of epistasis in the inheritance of seed yield and other related traits signifying the importance of recurrent selection in order to develop high yielding varieties. For pod length, both additive and dominant components were observed. Thus genetic improvement in seed yield would be easier through indirect selection for pod length.

Genetics of fruit yield and its component traits under different fruiting habit backgrounds in chilli (Capsicum annuum L.)

The six basic generations (two parents, F1, F2 and backcrosses) of 14 crosses developed from nine parents differing in fruits node−1 and fruit orientation were evaluated to decipher the genetics of three quantitative traits (average fruit weight, fruits plant−1 and green fruit yield plant−1) during the rainly season of 2016 and 2017. The magnitude and direction of the additive genetic effects [a], dominance genetic effects [d], magnitudes of additive genetic variance (σ2 A) and dominance genetic variance (σ2 D) varied with the genetic background of the crosses and traits. In the genetic background of crosses involving parents differing in fruit node−1, the inheritance of average fruit weight, fruits plant−1 and fruit yield plant−1 were controlled by the genes with both additive and ambidirectional dominant effects. On the contrary, genes with only additive effects controlled the inheritance of average fruit weight, fruits plant−1 and fruit yield plant−1 in most genetic backgrounds of crosses involving parents differing in fruit orientation and those differing in both fruits node−1 and fruit orientation. Further, the genes controlling the inheritance of all the traits are dispersed among the parents used in the investigation. These results are discussed in relation to strategies to be used in breeding chilli.

Estimation of genetic architecture of biochemical traits in mid–late cauliflower (Brassica oleracea L. var. botrytis) under sub-temperate conditions of north western Himalayas

Understanding the genetic basis of biochemical traits of different cauliflower genotypes is essential for planning the effective breeding strategies in genetic improvement. To determine the mode of inheritance of dry matter content and biochemical traits, we made crosses using four genotypes of cauliflower, and obtained F1, F2, BC1 and BC2 populations. The six generations obtained were replicated thrice and evaluated in a randomized block design. The generation mean analysis of data showed the presence of duplicate epistasis in dry matter content which suggested the adoption of reciprocal recurrent selection and biparental mating for the improvement of the trait. However, in case of vitamin C, complementary type of epistasis was reported in three crosses, which indicated the exploitation of heterosis breeding of enhancing vitamin C. It can be concluded that the role of gene action was in general more complex for the traits studied. The nature and magnitude of gene effects varies character-wise as well as cross-wise. Hence, for the improvement of dry matter content and biochemical traits in a particular cross, a specific breeding strategy has to be implemented.

Efficient Strategy to Identify Gene-Gene Interactions and Its Application to Type 2 Diabetes

Over the past decade, the detection of gene-gene interactions has become more and more popular in the field of genome-wide association studies (GWASs). The goal of the GWAS is to identify genetic susceptibility to complex diseases by assaying and analyzing hundreds of thousands of single-nucleotide polymorphisms. However, such tests are computationally demanding and methodologically challenging. Recently, a simple but powerful method, named “BOolean Operation-based Screening and Testing” (BOOST), was proposed for genome-wide gene-gene interaction analyses. BOOST was designed with a Boolean representation of genotype data and is approximately equivalent to the log-linear model. It is extremely fast, and genome-wide gene-gene interaction analyses can be completed within a few hours. However, BOOST can not adjust for covariate effects, and its type-1 error control is not correct. Thus, we considered two-step approaches for gene-gene interaction analyses. First, we selected gene-gene interactions with BOOST and applied logistic regression with covariate adjustments to select gene-gene interactions. We applied the two-step approach to type 2 diabetes (T2D) in the Korea Association Resource (KARE) cohort and identified some promising pairs of single-nucleotide polymorphisms associated with T2D.

Epistatic Interactions between CREB and CREM Variants in Affective Disorder

The aim of the present work is to investigate the existence of epistatic interactions possibly influencing psychotropic agents' response between rs6740584 within Cyclic adenosine monophosphate Response Element Binding (CREB) and rs12775799 within cAMP response element-modulator (CREM) variants in bipolar disorder (BD) and major depressive disorder (MDD). All BD and MDD patients were administered with the Young Mania Rating Scale (YMRS) and Hamilton Depression Rating Scale (HAMD) at baseline and at endpoint, respectively. A multiple regression model was employed to investigate the existence of possible epistatic interactions between the two variants and diverse clinical factors including drug response in affective disorders. No significant epistatic interaction was observed between rs6740584 within CREB and rs12775799 within CREM on both symptom improvement and other clinical factors in affective disorders. Our preliminary results suggest that no epistatic interaction between rs6740584 within CREB and rs12775799 within CREM should exist on clinical improvement and clinical factors in affective disorders.

Understanding Epistatic Interactions between Genes Targeted by Non-coding Regulatory Elements in Complex Diseases

Genome-wide association studies have proven the highly polygenic architecture of complex diseases or traits; therefore, single-locus-based methods are usually unable to detect all involved loci, especially when individual loci exert small effects. Moreover, the majority of associated single-nucleotide polymorphisms resides in non-coding regions, making it difficult to understand their phenotypic contribution. In this work, we studied epistatic interactions associated with three common diseases using Korea Association Resource (KARE) data: type 2 diabetes mellitus (DM), hypertension (HT), and coronary artery disease (CAD). We showed that epistatic single-nucleotide polymorphisms (SNPs) were enriched in enhancers, as well as in DNase I footprints (the Encyclopedia of DNA Elements [ENCODE] Project Consortium 2012), which suggested that the disruption of the regulatory regions where transcription factors bind may be involved in the disease mechanism. Accordingly, to identify the genes affected by the SNPs, we employed whole-genome multiple-cell-type enhancer data which discovered using DNase I profiles and Cap Analysis Gene Expression (CAGE). Assigned genes were significantly enriched in known disease associated gene sets, which were explored based on the literature, suggesting that this approach is useful for detecting relevant affected genes. In our knowledge-based epistatic network, the three diseases share many associated genes and are also closely related with each other through many epistatic interactions. These findings elucidate the genetic basis of the close relationship between DM, HT, and CAD.

Gene - Gene Interactions Among MCP Genes Polymorphisms in Asthma

PURPOSE: Monocyte chemoattractant proteins (MCPs) are important cytokines that involved in cellular activation and releasing of inflammatoy mediators by basophils and eosinophils in allergic disease. Some MCP gene variants implicate in asthma and monoclonal antibody for MCP-3 blocks allergic inflammations in the patients with asthma. Detection of interactions between gene and environment or between genes for complex disease such as asthma is important. We searched for an evidence of genetic effect of single nucleotide polymorphisms (SNPs) of MCP genes as well as gene - gene interactions involved in asthma. METHODS: Four hundreds asthmatics and four hundreds normal controls were enrolled. Asthma was defined as a positive bronchodilator response or positive methacholine provocation test with compatible clinical symptoms. Seven MCP gene SNPs (2 SNPs in MCP-1, 1 in MCP-2, and 4 in MCP-3) were included. Association analyses between SNP and asthma, and the tests for gene - gene interaction were performed. RESULTS: Strong linkage disequilibria were found among 7 MCP gene polymorphisms. There was no SNP that showed a significant association with asthma among 7 SNPs of 3 MCP genes. No haplotype was associated with asthma, either. The combination of MCP1-2518G>A, MCP2+46A>C, and MCP3+563C>T was the best predictive model for asthma as compared to the control in tests for gene - gene interaction. The MCP1-2518G>A and MCP2+46A>C was the second best predictive combination and this had the highest synergistic interaction effect on the subject's status than any other combination of polymorphisms. Complete linkages were not associated with the gene - gene interactions models. CONCLUSIONS: MCP gene polymorphisms probably interact with each other; thus, these findings may help in developing a possible genetic marker to predict asthma.

Gene - Gene Interactions Among MCP Genes Polymorphisms in Asthma

PURPOSE: Monocyte chemoattractant proteins (MCPs) are important cytokines that involved in cellular activation and releasing of inflammatoy mediators by basophils and eosinophils in allergic disease. Some MCP gene variants implicate in asthma and monoclonal antibody for MCP-3 blocks allergic inflammations in the patients with asthma. Detection of interactions between gene and environment or between genes for complex disease such as asthma is important. We searched for an evidence of genetic effect of single nucleotide polymorphisms (SNPs) of MCP genes as well as gene - gene interactions involved in asthma. METHODS: Four hundreds asthmatics and four hundreds normal controls were enrolled. Asthma was defined as a positive bronchodilator response or positive methacholine provocation test with compatible clinical symptoms. Seven MCP gene SNPs (2 SNPs in MCP-1, 1 in MCP-2, and 4 in MCP-3) were included. Association analyses between SNP and asthma, and the tests for gene - gene interaction were performed. RESULTS: Strong linkage disequilibria were found among 7 MCP gene polymorphisms. There was no SNP that showed a significant association with asthma among 7 SNPs of 3 MCP genes. No haplotype was associated with asthma, either. The combination of MCP1-2518G>A, MCP2+46A>C, and MCP3+563C>T was the best predictive model for asthma as compared to the control in tests for gene - gene interaction. The MCP1-2518G>A and MCP2+46A>C was the second best predictive combination and this had the highest synergistic interaction effect on the subject's status than any other combination of polymorphisms. Complete linkages were not associated with the gene - gene interactions models. CONCLUSIONS: MCP gene polymorphisms probably interact with each other; thus, these findings may help in developing a possible genetic marker to predict asthma.

Gene-Gene Interaction Between CCR3 and Eotaxin Genes: The Relationship With Blood Eosinophilia in Asthma

PURPOSE: Eosinophils function as an effector cell in the development of asthma and allergic disease. Eotaxins are cytokines that promote pulmonary eosinophilia via the receptor CCR3. Single-nucleotide polymorphisms (SNPs) in CCR3 and eotaxin genes are associated with asthma. In this study, genetic interactions among SNPs of several eotaxin genes and CCR3 were assessed and their relationship with blood eosinophilia in asthma was examined. METHODS: A total of 533 asthmatics were enrolled in this study. Asthmatics with eosinophilia (>0.5x109/L) were compared with those without eosinophilia (A (29L>I) was significantly associated with 3 of the 4 CCR3 SNPs among asthmatics with eosinophilia (P=0.037-0.009). EOT2+304C>A (29L>I) and the CCR3 SNPs were also significantly associated with blood eosinophilia in an interaction model constructed by logistic regression (P=0.0087). GMDR analysis showed that the combination of EOT2+304C>A (29L>I) and CCR3-174C>T was the best model (accuracy=0.536, P=0.005, CVC 9/10). CONCLUSIONS: The epistatic influence of CCR3 on eotaxin gene variants indicates that these variants may be candidate markers for eosinophilia in asthma.

Asociación y efectos de interacción en los genes AGT , AGTR1 , ACE , ADRB2 , DRD1 , ADD1, ADD2, ATP2B1, TBXA2R y PTGS2 sobre la hipertensión en la población antioqueña / Association and interaction of AGT, AGTR1, ACE, ADRB2, DRD1, ADD1, ADD2, ATP2B1, TBXA2R and PTGS2 genes on the risk of hypertension in Antioquian population

Introducción. La hipertensión arterial es una enfermedad multifactorial influenciada por componentes genéticos y ambientales, cuya prevalencia varía entre grupos étnicos. Se han llevado a cabo numerosos estudios en genes de sistemas reguladores de la presión arterial, como el sistema renina-angiotensinaaldosterona, el sistema nervioso simpático, los factores endoteliales, y el balance de sodio, mostrando resultados incongruentes entre poblaciones. Objetivos. Evaluar el efecto de variantes en los genes AGT , AGTR1 , ACE , ADRB2 , DRD1 , ADD1 , ADD2 , ATP2B1 , TBXA2R y PTGS2 y del componente ancestral individual, sobre la hipertensión arterial y las cifras de presión arterial en una muestra de población antioqueña. Materiales y métodos. Se genotipificaron 107 casos y 253 controles para 12 variantes en los genes AGT , AGTR1 , ACE , ADRB2 , DRD1 , ADD1 , ADD2 , ATP2B1 , TBXA2R y PTGS2 , y para 20 marcadores informativos de ascendencia. Se evaluó la asociación de los polimorfismos y sus interacciones, y de la composición genética ancestral con hipertensión y cifras de presión arterial. Resultados. Los genes ADD2 , rs4852706 (OR=3,0; p=0,023); DRD1 , rs686 (OR=0,38; p=0,012) y ADRB2 , rs1042718 (OR=10,0; p=0,008); y combinaciones genotípicas de DRD1 con AGTR1 ; de AGT con ADD1 ; y de ADD1 con ATP2B1 y PTGS2 , se asociaron con hipertensión arterial. El componente ancestral amerindio se asoció con disminución en la presión arterial diastólica. Conclusiones. Variantes en los genes ADD2 , DRD1 , ADRB2 , AGTR1 , AGT , ADD1 , ATP2B1 y PTGS2 , individualmente o en su interacción, se encuentran asociadas con hipertensión. El componente ancestral amerindio tiene un efecto sobre las cifras de presión arterial.

Introduction: Hypertension is a multifactorial disease influenced by genetic and environmental components, with its prevalence varying across ethnic groups. Manifold studies on blood pressure regulatory system genes have been carried out -such as the renin-angiotensin-aldosterone system, the sympathetic nervous system, endothelial factor, and sodium balance-, but the results yielded were inconsistent among populations. Objectives: To evaluate the effect of both variants in genes AGT, AGTR1, ACE, ADRB2, DRD1, ADD1, ADD2, ATP2B1, TBXA2R PTGS2, and the result of the individual ancestry component on hypertension and blood pressure levels among population in Antioquia. Methods and materials: 107 cases and 253 controls were genotyped for 12 variants on genes AGT, AGTR1, ACE, ADRB2, DRD1, ADD1, ADD2, ATP2B1, TBXA2R y PTGS2, and for 20 ancestry informative markers. The association of polymorphisms and their interactions, and the association of ancestral genetic composition with hypertension and blood pressure levels were examined. Results: Genes ADD2, rs4852706 (OR=3.0; p=0.023); DRD1, rs686 (OR=0.38; p=0.012) and ADRB2, rs1042718 (OR=10.0; p=0.008); as well as genotypic combinations of DRD1 and AGTR1; AGT and ADD1; and ADD1 to ATP2B1 and PTGS2 were associated to hypertension. The Amerindian ancestry component was associated to some decrease in diastolic blood pressure. Conclusion: Variants on genes ADD2, DRD1, ADRB2, AGTR1, AGT, ADD1, ATP2B1 and PTGS2 individually or interacting, are associated to hypertension. The Amerindian ancestry component has an effect on blood pressure.

Interactions between 5-1ipoxygenase-activating protein and cytochrome P450 3A5 gene variants significantly increase the risk of cerebral infarction / 中华神经科杂志

Objective To investigate 4 variants single nucleotide polymorphisms (SNPs) of 5-lipoxygenase-activating protein(ALOX5AP) in lipoxygenase pathway and in cytochrome P450 pathway as susceptibility genes for stroke in a southeastern Chinese population,and evaluate the associations between susceptibility genes and cerebral infarction,to find whether gene-gene interactions increase the risk of cerebral infarction.Methods By case-control study,two hundred and ninety-two patients with cerebral infarction and 259 healthy control subjects were included.Eight variants in 5 candidate genes were examined for stroke risk,including the SG13S32 (rs9551963),SG13S42 (rs4769060),SG13S89 (rs4769874),and SG13Sl14 (rs10507391) variants of the ALOX5AP gene,the G860A (rs751141) variant of the soluble epoxide hydrolase (EPHX2) gene,the A1075C (rs1057910) variant of the CYP2C9 *2 gene,the C430T (rs1799853) variant of the CYP2C9* 3 gene,and the A6986G (rs776746) variant of the CYP3A5 gene.Gene-gene interactions were explored using generalized multifactor dimensionality reduction (GMDR)methods.Results There were no statistically significant differences in the frequencies of the genotypes of the 8 candidate genes.The GMDR analysis showed a significant gene-gene interaction between SG13S114 and A6986G,with scores of 10 for cross-validation consistency and 9 for the sign test (P =0.011).These genegene interactions predicted a significantly higher risk of cerebral infarction (adjusted for age,hypertension,and diabetes mellitus;OR =1.804,95％ CI 1.180-2.759,P =0.006).Conclusions A two-loci gene interaction confers significantly higher risk for cerebral infarction.The combinational analysis used in this study may be helpful in the elucidation of genetic risk factors for common and complex diseases.

Evidencia de asociación entre el gen SLC6A4 y efectos epistáticos con variantes en HTR2A en la etiología del autismo en la población antioqueña / Evidence for association and epistasis between the genetic markers SLC6A4 and HTR2A in autism etiology

Introducción. El espectro autista constituye un grupo de trastornos graves del neurodesarrollo, con un fuerte componente genético. Se ha sugerido un papel importante del sistema serotoninérgico en el desarrollo de este grupo de trastornos, con base en los estudios de respuesta a medicamentos y la hiperserotoninemia, característica común en el autismo. Se han implicado múltiples moléculas en el metabolismo y la neurotransmisión de la serotonina; sin embargo, los resultados de los estudios han tenido poca congruencia entre diferentes poblaciones. Objetivos. Evaluar la relación entre el autismo y el polimorfismo de nucleótido simple (Single Nucleotide Polymorphism, SNP) en los genes SLC6A4, HTR2A e ITGB3, en una muestra de la población antioqueña. Materiales y métodos. Se genotipificaron 42 núcleos familiares con autismo para 10 variantes en los genes SLC6A4, ITGB3 y HTR2A. Se evaluó la asociación utilizando la prueba de desequilibrio en la transmisión. Se exploró el impacto de la interacción entre estos genes y el autismo, utilizando la reducción multidimensional. Resultados. Se encontró asociación de las variantes rs4583306 (OR=2,6, p=0,004) y rs2066713 (OR=2,2 p=0,03), en el gen SLC6A4, y asociación de combinaciones genotípicas entre los genes SLC6A4 y HTR2A y el riesgo de autismo (p=0,0001). Conclusiones. Se encontró asociación significativa con variantes en el gen transportador de serotonina con el autismo, al igual que interacción entre variantes en los genes HTR2A con SLC6A4. Estos resultados concuerdan con los de estudios previos en otras poblaciones y son pruebas a favor del papel del sistema serotoninérgico en la etiología del espectro autista.

Introduction. Autism spectrum disorders are severe neurodevelopmental disorders with a strong genetic component. The potential role of the serotoninergic system in the development of autistic disorder has been based on the observation of hyperserotoninemia in autistic subjects and the results of drug treatment studies. Multiple molecules involved in serotonin metabolism and neurotransmission have been studied; however, replication studies have been inconsistent. This may be partially related to the marked genetic heterogeneity of autism in different populations. Objectives. The relationship between autism and single nucleotide polymorphisms of SLC6A4, HTR2A and ITGB3 genes was evaluated in an urban population of northwestern Colombia. Materials and methods. In Antioquia, Colombia, 42 families with history of autism were screened for 10 SNPs in SLC6A4, HTR2A and ITGB3 genes and evaluated for associations with the transmission disequilibrium test. The interactions among these genes and autism was assessed with multidimensional reduction methods. Results. A significant main effect was seen among the SLC6A4 gene variants rs4583306 (OR=2.6, p=0.004) and rs2066713 (OR=2.2, p=0.03). No main effect of the ITGB3 or HTR2A variants was found, however, in the interaction effects, the SLC6A4 and HTR2A genes demonstrated significant evidence of association with autism (p<0.001). Conclusion. Significant association of markers were discovered within the SLC6A4 gene and the combination of SLC6A4 and HTR2A (S-A) genes to autism. These results were consistent with previous studies conducted in other populations and provide further evidence for the implication of the serotoninergic system in the etiology of autistic disorders.

Efecto de la portación de alelos de riesgo de MAO-A y DRD4 sobre mediciones de agresión / Effect of Risk Alleles MAO-A and DRD4 on Aggression Measures

Entre los diversos factores asociados con la predisposición a la conducta violenta se encuentra la portación de alelos de riesgo. Para investigar el efecto de dos alelos de riesgo (baja actividad de MAO-A y 7 repeticiones DRD4) sobre mediciones de agresión, se evaluaron mediante escalas psicológicas a 60 hombres sanos. Los resultados indicaron que tanto el efecto principal de cada uno de los alelos de riesgo, como su interacción impactan sobre mediciones de hostilidad, enojo, impulsividad, empatía y rasgos antisociales de psicopatía. Se concluye que es necesario investigar el efecto de estos alelos sobre la estructura y función cerebrales, además estos alelos aparentemente confieren riesgo para el desarrollo de conductas violentas.

Among the factors associated with the predisposition to violent behavior is the bearing of risk alleles. To investigate the effect of two risk alleles (low activity of MAO-A and 7 repeat DRD4) 60 healthy men were assessed on psychological scales of aggression. The results indicated that both the main effect of each of the risk alleles, and their interaction impact on measures of hostility, anger, impulsivity, empathy and antisocial traits of psychopathy. We conclude that it is necessary to investigate the effect of these alleles on brain structure and function; these alleles apparently also confer risk for the development of violent behavior.

Lack of evidence for intermolecular epistatic interactions between adiponectin and resistin gene polymorphisms in Malaysian male subjects

Epistasis (gene-gene interaction) is a ubiquitous component of the genetic architecture of complex traits such as susceptibility to common human diseases. Given the strong negative correlation between circulating adiponectin and resistin levels, the potential intermolecular epistatic interactions between ADIPOQ (SNP+45T > G, SNP+276G > T, SNP+639T > C and SNP+1212A > G) and RETN (SNP-420C > G and SNP+299G > A) gene polymorphisms in the genetic risk underlying type 2 diabetes (T2DM) and metabolic syndrome (MS) were assessed. The potential mutual influence of the ADIPOQ and RETN genes on their adipokine levels was also examined. The rare homozygous genotype (risk alleles) of SNP-420C > G at the RETN locus tended to be co-inherited together with the common homozygous genotypes (protective alleles) of SNP+639T > C and SNP+1212A > G at the ADIPOQ locus. Despite the close structural relationship between the ADIPOQ and RETN genes, there was no evidence of an intermolecular epistatic interaction between these genes. There was also no reciprocal effect of the ADIPOQ and RETN genes on their adipokine levels, i.e., ADIPOQ did not affect resistin levels nor did RETN affect adiponectin levels. The possible influence of the ADIPOQ gene on RETN expression warrants further investigation.

Epistasis and genotype-by-environment interaction of grain protein content in durum wheat

Parental, F1, F2, BC1 and BC2 generations of four crosses involving four cultivars of durum wheat (Triticum durum Desf.) were evaluated at two sites in Tunisia. A three-parameter model was found inadequate for all cases except crosses Chili x Cocorit 71 at site Sidi Thabet and Inrat 69 x Karim at both sites. In most cases a digenic epistatic model was sufficient to explain variation in generation means. Dominance effects (h) and additive x additive epistasis (i) (when significant) were more important than additive (d) effects and other epistatic components. Considering the genotype-by-environment interaction, the non-interactive model (m, d, h, e) was found adequate. Additive variance was higher than environmental variance in three crosses at both sites. The estimated values of narrow-sense heritability were dependent upon the cross and the sites and were 0 percent-85 percent. The results indicate that appropriate choice of environment and selection in later generations would increase grain protein content in durum wheat.

Controle genético da incompatibilidade do cruzamento entre cultivares andinas e mesoamericanas de feijoeiro comum / Genetic control of incompatibility in crosses of andean and mesoamerican common bean cultivars

Normalmente, ocorre incompatibilidade nos cruzamentos entre feijoeiros de origem andina com mesoamericanas. Há dúvidas no controle genético do caráter. Singh & Gutiérrez (1984) relataram que no controle do caráter estão envolvidos dois genes e ocorre epistasia recessiva dupla. Vilarinho (2004) apresentou resultados, relatando que não seriam apenas dois genes. Para melhor elucidar o controle genético desse caráter foi realizado o presente trabalho. Para isso, a cultivar de origem andina 'Jalo EEP 558' foi cruzada com a 'Small White', que é mesoamericana, porém compatível com a anterior. A cultivar de origem mesoamericana 'Mulatinho da Vagem Roxa' também foi cruzada com a 'Small White'. As gerações F1 desses dois híbridos foram cruzadas entre si. As sementes resultantes foram semeadas no campo e avaliada a ocorrência ou não da incompatibilidade. Constatou-se a segregação de três plantas normais para uma incompatível. Esse resultado evidencia que são dois genes, DL1 e DL2, e que o genótipo das cultivares envolvidas são: 'Jalo EEP 558' dl1dl1DL2DL2 ; 'Mulatinho da Vagem Roxa' DL1DL1dl2dl2 ; 'Small White' dl1dl1dl2dl2.

Crosses between Andean and Mesoamerican common beans are usually incompatible. There are doubts about the genetic control of the trait. Singh & Gutiérrez (1984) reported that two genes are involved in the trait control and that double recessive epistasis occurs. On the other hand, Vilarinho (2004) presented results indicating that more than two genes are involved. The present study was carried out to clarify the genetic control of this trait. For this purpose, the Andean cultivar 'Jalo EEP 558' was crossed with 'Small White', which is Mesoamerican, but compatible with the former one. The Mesoamerican cultivar 'Mulatinho da Vagem Roxa' was also crossed with 'Small White'. The F1 generation of these two hybrids was crossed with each other. The resulting seeds were sown on the field and the occurrence of incompatibility was evaluated. Segregation of 3 (normal) to 1 (incompatible) plants was observed, indicating that there are two genes, DL1 and DL2, as reported by Singh & Gutiérrez (1984), and that the genotype of the cultivars involved are: 'Jalo EEP 558' dl1dl1DL2DL2 ; 'Mulatinho da Vagem Roxa' DL1DL1dl2dl2 ; 'Small White' dl1dl1dl2dl2.