ABSTRACT
The aim of the study was to investigate pig reference families, generated from Korean native pigs (KNP) that were crossed with Yorkshire (YS) breeds, which were used to evaluate genetic markers to select breeding animals with superior pork quality. A set of five candidate genes (PRKAG3, MC4R, CAST, ESR, and PRLR) was analyzed for association with pork quality traits. PRKAG3 (I199V) SNP genotypes were significantly associated with muscle moisture, protein, and fat contents. The MC4R D298N polymorphism was significantly associated with meat tenderness and color traits. The CAST polymorphism was significantly associated with muscle moisture and crude protein traits. These three genes have been associated with pork quality traits in other pig populations, and some of our results are consistent with earlier studies. In addition, two reproductive candidate genes (ESR and PRLR) did not have significant associations. These results suggest that further study is warranted to investigate and develop more DNA markers associated with pork quality in our KNP-crossed pig families.
Subject(s)
Animals , Humans , Breeding , DNA , Genetic Markers , Genotype , Meat , Muscles , Polymorphism, Single Nucleotide , SwineABSTRACT
Uma estratégia comum em programas de melhoramento é conduzir estudos básicos de herança para investigar a hipótese de controle do caráter por um ou poucos genes de efeito principal, associados ou não a genes modificadores de pequeno efeito. Neste trabalho, foi utilizada a inferência bayesiana para ajustar modelos de herança genética aditiva-dominante a experimentos de genética vegetal com várias gerações. Densidades normais com médias associadas aos efeitos genéticos das gerações foram consideradas em um modelo linear em que a matriz de delineamento dos efeitos genéticos tinha coeficientes indeterminados (precisando ser estimada para cada indivíduo). A metodologia foi ilustrada com um conjunto de dados de um estudo de herança da partenocarpia em abobrinha (Cucurbita pepo L). Tal ajuste permitiu explicitar a distribuição a posteriori das probabilidades genotípicas. A análise corrobora resultados anteriores da literatura, porém foi mais eficiente que alternativas prévias que supunham a matriz de delineamento conhecida para as gerações. Conclui-se que a partenocarpia em abobrinha é governada por um gene principal com dominância parcial.
A common breeding strategy is to carry out basic studies to investigate the hypothesis of a single gene controlling the trait (major gene) with or without polygenes of minor effect. In this study we used Bayesian inference to fit genetic additive-dominance models of inheritance to plant breeding experiments with multiple generations. Normal densities with different means, according to the major gene genotype, were considered in a linear model in which the design matrix of the genetic effects had unknown coefficients (which were estimated in individual basis). An actual data set from an inheritance study of partenocarpy in zucchini (Cucurbita pepo L.) was used for illustration. Model fitting included posterior probabilities for all individual genotypes. Analysis agrees with results in the literature but this approach was far more efficient than previous alternatives assuming that design matrix was known for the generations. Partenocarpy in zucchini is controlled by a major gene with important additive effect and partial dominance.
ABSTRACT
Our previous studies have found significant quantitative changes in the erythrocyte membrane proteins in essential hypertension (EH). The purpose of the present study was to quantify genetic and environmental contributions to quantitative variability of erythrocyte membrane proteins in EH. We studied 115 hypertensive patients, 126 normotensive subjects, 235 of their first-degree relatives and 24 twin pairs by sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis. The decomposition of total phenotypic variance of erythrocyte membrane proteins to genetic and environmental components was performed by the least squares method. We found that genetic factors play a significant role in the control of quantitative changes in erythrocyte membrane proteins in EH. The genetic contribution to anion exchanger variation was stronger in hypertensives (88%) than in normotensives (36%), and was attributed exclusively to additive polygenic effects. Variation in glucose transporter was under marked control of major gene effect (74%). Importantly, variations in anion and glucose transporters in EH but not in healthy controls were strongly affected by common underlying genes with strong pleiotropic effects (r=0.921, P<0.05). These data provide evidence to support the genetic source of quantitative changes in membrane proteins in EH. Furthermore, the pleiotropic effects of common underlying genes seem to be responsible for variations in the transport proteins likely associated with genetic susceptibility to essential hypertension.
ABSTRACT
PURPOSES: The aim of this study was to investigate the familial correlation of lipid profile and the mode of inheritance of LDL-cholesterol through segregation analysis. The study population included 414 family members of 67 Probands who had a coronary heart disease. METHODS: Gene frequency(qH) of the allele for high LDL-cholesterol levels, means of each genotypes, and other putative gene related parameters were estimated. Maximum likelihood methods were used to fit several genetic and nongenetic modes of inheritance to these data to determine if an unobserved Mendelian major gene could explain the familial distribution of LDL-cholesterol. LDL-cholesterol levels were adjusted for age, gender, body mass index, smoking and alcohol consumption. RESULTS: LDL-cholesterol levels revealed familial correlation among spouses, parent-offsprings and siblings with correlations of 0.10, 0.22, and 0.32, respectively. The heritability of LDL-cholesterol was 53%. Two models of inheritance in LDL-cholesterol distribution, the Mendelian codominant model and the polygenic equal transmission model were found. Comparison of these two models in each family among 67 families showed that thiry-six families favored the major gene model with Mendelian codominant and thirty-one families favored the polygenic model of equal transmission. In families favoring Mendelian codominant inheritance, means of each genotypes; LL, HL, HH were 102.1, 143.3, 248.4 mg/dl and gene frequency of H allele was 0.08. In families favoring equal transmission inheritance, means of each genotypes were 101.6, 122.7, 185.5 mg/dl and gene frequency of H allele was 0.14. CONCLUSIONS: In conclusion, families of coronary heart disease patients of this study showed substantial familial correlation and results suggested that variation in LDL-cholesterol may be influenced by major gene effect.
Subject(s)
Humans , Alcohol Drinking , Alleles , Body Mass Index , Coronary Disease , Gene Frequency , Genotype , Siblings , Smoke , Smoking , Spouses , WillsABSTRACT
Elevated plasma level of factor VII is a risk factor for coronary artery disease. We investigated environmental, familial, and genetic influences on factor VII levels. We used maximum likelihood segregation analysis to fit several genetic and nongenetic modes of inheritance to the data to determine whether Mendelian inheritance of a major gene could best explain the familial distribution of factor VII. The study population included 414 family members of 67 subjects who had undergone elective coronary arteriography. The factor VII level was adjusted for age, gender, body mass index, smoking and alcohol drinking (R2=20.6%). Factor VII levels revealed strong familial aggregation with estimated correlation spouse of 0.12, parent-offspring of 0.31, and siblings of 0.40. Regressive models were used to examine inter-individual variation in adjusted factor VII levels in these 67 families. This analysis strongly favored a major gene model with codominant transmission. Genotypic means were 111.6, 123.2, and 184.3% with relative frequencies of 59.4%, 35.4%, and 5.2%. This putative major gene explains 39.9% of the total variance of factor VII. Likelihood was used to search for etiologic heterogeneity by sorting pedigrees into groups that favor one model over another. Compared to pedigrees less favoring Mendelian models, pedigrees favoring Mendelian codominant models have almost 8 times earlier onset of coronary heart disease. These family data suggest that there are strong familial and genetic effects on the factor VII activity in these high risk families. Therefore, linkage studies in these families may be worthwhile to clarify the molecular basis of factor VII levels.