Home About us Contact
|
Home About us Contact | ||
|
|
||
MC4R Gene (mc4r + gene)
Selected AbstractsAssociation of a melanocortin 4 receptor (MC4R) polymorphism with performance traits in Lithuanian White pigsJOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 1 2006R. Jokubka Summary The melanocortin 4 receptor is expressed in virtually all brain regions of mammals and plays an important role in energy homeostasis. Polymorphisms in this gene may thus be related to growth and obesity. In pigs, a non-synonymous polymorphic site was described (Asp298Asn) and demonstrated to affect cAMP production and to alter adenylyl cyclase signalling. Association studies revealed significant linkage of this mutation with production trait in pigs. In this study, 207 Lithuanian White pigs were genotyped at the MC4R locus and analysed on relationships between genotype and breeding values for several performance traits. The observed allele and genotype frequencies did not deviate significantly from Hardy,Weinberg equilibrium (wildtype allele 0.59; mutant allele 0.41) and are comparable with those described in other Large White populations. The mutant Asn298 allele of the MC4R gene was significantly associated with increased test daily gain, higher lean meat percentage and lower backfat thickness. There was a trend towards an improved feed conversion ratio (p = 0.065) in animals with the mutant allele whereas no significant effect was found on lifetime daily gain. These results indicate that the MC4R polymorphism should be integrated in selection programmes in the Lithuanian White to improve carcass composition. [source] Variation analysis of ,3 -adrenergic receptor and melanocortin-4 receptor genes in childhood obesityPEDIATRICS INTERNATIONAL, Issue 2 2007TOMOE KINOSHITA Abstract Background: Decreased energy expenditure and increased food intake are principal causes for obesity. In the present study, genotypes of ,3 -adrenergic receptor (,3AR) and of melanocortin-4 receptor (MC4R), both of which are believed to have a close link to the cause of obesity, were analyzed and compared with phenotypes of childhood obesity. Methods: Thirty-five obese children with moderate to severe obesity were enrolled. Direct sequencing of the MC4R coding region and pinpoint-polymerase chain reaction were used to detect genomic variation in the ,3AR gene using peripheral blood-derived DNA. Results: Allele frequency of Trp64Arg variation in the ,3AR gene in the obese subjects was 0.16, which is comparable with that in the healthy general population in eastern Asia. Comparison of phenotypical characteristics did not show a significant difference between Trp/Trp and Trp/Arg subjects. It was notable that body height SD was significantly higher in the Trp/Trp than the Trp/Arg subjects (0.93 ± 1.0 SD vs 0.07 ± 1.3 SD, P= 0.03). Annual weight gains were far beyond a hypothetical fat gain in an Arg64 heterozygote with decreased energy consumption, suggesting increased food intake in childhood obesity. There was, however, no variation in the MC4R gene despite thorough sequencing of the entire coding region. Conclusions: The Trp64Arg variation in the ,3AR gene has no relationship to the degree or the incidence of childhood obesity. The majority of childhood obesity can be characterized as tall stature, more rapid weight gain than that expected by decreased energy expenditure. Further investigation is necessary in regard to the increased food intake as a major cause of childhood obesity. [source] Detailed characterization of the porcine MC4R gene in relation to fatness and growthANIMAL GENETICS, Issue 4 2009B. Fan Summary In contrast to the human MC4R gene, where multiple variants have been described, several of which are associated with appetite and obesity, few MC4R variants have been reported in the pig. The most interesting polymorphism reported to date in the pig is p.Asp298Asn, which is significantly associated with variation in growth and fatness traits in most breeds and crosses. However, some reports have seemingly failed to confirm this association. The discrepancy of p.Asp298Asn associations in some pig populations suggested that further discovery of SNPs in MC4R would be useful. Utilizing the recently released pig genome sequence information, we obtained the whole MC4R genome sequence and detected five additional SNPs, a variable (CA)n repeat and a C indel in the ISU Berkshire × Yorkshire pig resource family. Linkage disequilibrium (LD) analysis revealed that the additional five SNPs were not in strong LD with p.Asp298Asn, but single marker association analysis indicated that they were significantly (P < 0.05) associated with fatness measures and very highly significantly (P < 0.0001) associated with average daily gain on test (ADGTEST). Three major haplotypes were identified and the subsequent association analyses suggested that the two non-synonymous SNPs had different effects, e.g. p.Arg236His influenced back fat and growth on test while p.Asp298Asn was primarily associated with variation in growth rate in this population. An interaction effect between these two SNPs was found for ADGTEST, which may partly explain some of the previous discrepancies reported for MC4R in different pig populations. Examination of the p.Arg236His polymorphism in populations where the effect of p.Asp298Asn is limited is warranted. [source] Association of the melanocortin 4 receptor with feed intake and daily gain in F2 Mangalitsa × Piétrain pigsANIMAL GENETICS, Issue 3 2006K. Meidtner Summary The melanocortin 4 receptor (MC4R) is a key factor in the regulation of energy balance and body weight. Hence it is a candidate for feed intake and energy homeostasis-related traits. Studies in humans and swine have revealed several sequence variants in the gene that are associated with some of these traits. In pigs the coding non-synonymous missense variant Asp298Asn in MC4R has been associated with feed intake, fatness and growth. Here we confirm the association of this Piétrain-derived polymorphism with feed intake and daily gain in the F2 generation of a Mangalitsa × Piétrain cross. In one Piétrain founder animal, we detected an additional non-synonymous missense variant Arg236His. Thus, the MC4R gene could be a useful marker for increased growth in the relatively slow-growing Piétrain breed. [source] A SNP in the cattle MC4R gene is used to map MC4R to BTA 24ANIMAL GENETICS, Issue 6 2001T. D. Thue [source] Genetic variation and decreased risk for obesity in the Atherosclerosis Risk in Communities StudyDIABETES OBESITY & METABOLISM, Issue 4 2007M. L. Hart Sailors Aim:, To investigate the effects of variation in the leptin [LEP (19A>G)] and melanocortin-4 receptor [MC4R (V103I)] genes on obesity-related traits in 13,405 African-American (AA) and white participants from the Atherosclerosis Risk in Communities (ARIC) Study. Methods:, We tested the association between the single-locus and multilocus genotypes and obesity-related measures [body mass index (BMI), body weight (BW), waist,hip ratio, waist circumference and leptin levels], adjusted for age, physical activity level, smoking status, diabetic status, prevalence of coronary heart disease, hypertension, stroke or transient ischaemic attack. Results:, AA and white female carriers of the MC4R I103 allele exhibited significantly lower BW than non-carriers of this allele (p < 0.05 and p < 0.01 respectively). AA female carriers of both the LEP A19 allele and the MC4R I103 allele were 63% [odds ratio (OR) = 0.37, 95% confidence interval (CI) (0.18,0.78)] less likely to be obese, and white female carriers of the same two alleles were 46% [OR = 0.54, 95% CI (0.32,0.91)] less likely to be obese, than non-carriers of the variant alleles. Female carriers of both the LEP A19 and MC4R I103 alleles had significantly lower BW (p < 0.05), BMI (p < 0.05) and plasma leptin (p < 0.01) than the non-carriers of both the alleles. Carriers of the two variant alleles had lower BMI over the 9-year course of the ARIC study and significantly lower weight gain from age 25 years. No significant joint effect of these two variants was observed in males. Conclusion:, These results suggest that variation within the LEP and MC4R genes is associated with reduced risk for obesity in females. [source] | ||||||||||