Polymorphisms of the FTO gene are associated with variation in energy intake, but not energy expenditure.

The FTO gene has significant polymorphic variation associated with obesity, but its function is unknown. We screened a population of 150 whites (103F/47M) resident in NE Scotland, United Kingdom, for variants of the FTO gene and linked these to phenotypic variation in their energy expenditure (basal metabolic rate (BMR) and maximal oxygen consumption VO(2)max) and energy intake. There was no significant association between the FTO genotype and BMR or VO(2)max.

n-3 Fatty acid erythrocyte membrane content, APOE varepsilon4, and cognitive variation: an observational follow-up study in late adulthood.

Background: Evidence for an inverse relation between dietary intake of n-3 polyunsaturated fatty acids (PUFAs) and age-related cognitive decline is inconsistent. This inconsistency may arise because the relation is present only in the absence of the apolipoprotein E epsilon4 (APOE epsilon4) allele.

Objective: We aimed to determine the contribution of erythrocyte n-3 PUFA content to cognitive aging in the presence or absence of the APOE epsilon4 allele.

Quantitative trait Loci for regional adiposity in mouse lines divergently selected for food intake.

Objective: Obesity is thought to result from an interaction between genotype and environment. Excessive adiposity is associated with a number of important comorbidities; however, the risk of obesity-related disease varies with the distribution of fat throughout the body. The aim of this study was to map quantitative trait loci (QTLs) associated with regional fat depots in mouse lines divergently selected for food intake corrected for body mass.

Factors influencing variation in basal metabolic rate include fat-free mass, fat mass, age, and circulating thyroxine but not sex, circulating leptin, or triiodothyronine.

Background: Basal metabolic rate (BMR) is the largest component of daily energy demand in Western societies. Previous studies indicated that BMR is highly variable, but the cause of this variation is disputed. All studies agree that variation in fat-free mass (FFM) plays a major role, but effects of fat mass (FM), age, sex, and the hormones leptin, triiodothyrionine (T3), and thyroxine (T4) remain uncertain.

A paternally imprinted QTL for mature body mass on mouse chromosome 8.

Body mass (BM) is a classic polygenic trait that has been extensively investigated to determine the underlying genetic architecture. Many previous studies looking at the genetic basis of variation in BM in murine animal models by quantitative trait loci (QTL) mapping have used crosses between two inbred lines. As a consequence it has not been possible to explore imprinting effects which have been shown to play an important role in the genetic basis of early growth with persistent effects throughout the growth curve.

A QTL affecting daily feed intake maps to Chromosome 2 in pigs.

Our understanding of the molecular genetic basis of several key performance traits in pigs has been significantly advanced through the quantitative trait loci (QTL) mapping approach. However, in contrast to growth and fatness traits, the genetic basis of feed intake traits has rarely been investigated through QTL mapping. Since feed intake is an important component of efficient pig production, the identification of QTL affecting feed intake may lead to the identification of genetic markers that can be used in selection programs.

Mice with low metabolic rates are not susceptible to weight gain when fed a high-fat diet.

Objective: Mice divergently selected for high or low food intake (FI) at constant body mass differ in their resting metabolic rates (RMRs). Low-intake individuals (ML) have significantly lower RMR (by 30%) compared with those from the high-intake line (MH). We hypothesized that MLs might, therefore, be more likely to increase their body and fat mass when exposed to a high-fat diet (HFD).

Identification and reciprocal introgression of a QTL affecting body mass in mice.

The aim of this study was to examine the effects of a QTL in different genetic backgrounds. A QTL affecting body mass on chromosome 6 was identified in an F(2) cross between two lines of mice that have been divergently selected for this trait. The effect of the QTL on mass increased between 6 and 10 weeks of age and was not sex-specific.