A Mendelian trait for olfactory sensitivity affects odor experience and food selection.

Humans vary in acuity to many odors [1-4], with variation within olfactory receptor (OR) genes contributing to these differences [5-9]. How such variation also affects odor experience and food selection remains uncertain [10], given that such effects occur for taste [11-15]. Here we investigate ß-ionone, which shows extreme sensitivity differences [4, 16, 17]. ß-ionone is a key aroma in foods and beverages [18-21] and is added to products in order to give a pleasant floral note [22, 23]. Genome-wide and in vitro assays demonstrate rs6591536 as the causal variant for ß-ionone odor sensitivity. rs6591536 encodes a N183D substitution in the second extracellular loop of OR5A1 and explains >96% of the observed phenotypic variation, resembling a monogenic Mendelian trait. Individuals carrying genotypes for ß-ionone sensitivity can more easily differentiate between food and beverage stimuli with and without added ß-ionone. Sensitive individuals typically describe ß-ionone in foods and beverages as "fragrant" and "floral," whereas less-sensitive individuals describe these stimuli differently. rs6591536 genotype also influences emotional associations and explains differences in food and product choices. These studies demonstrate that an OR variant that influences olfactory sensitivity can affect how people experience and respond to foods, beverages, and other products.

Identification of regions associated with variation in sensitivity to food-related odors in the human genome.

Humans vary in their ability to smell numerous odors [1-3], including those associated with food [4-6]. Odor sensitivity is heritable [7-11], with examples linking genetic variation for sensitivity to specific odors typically located near olfactory receptor (OR) genes [12-16]. However, with thousands of aromas and few deorphaned ORs [17, 18], there has been little progress toward linking variation at OR loci to odor sensitivity [19, 20]. We hypothesized that OR genes contain the variation that explains much of the differences in sensitivity for odors, paralleling the genetics of taste [21, 22], which affect the flavor experience of foods [23-25]. We employed a genome-wide association approach for ten food-related odors and identified genetic associations to sensitivity for 2-heptanone (p = 5.1 × 10(-8)), isobutyraldehyde (p = 6.4 × 10(-10)), ß-damascenone (p = 1.6 × 10(-7)), and ß-ionone (p = 1.4 × 10(-31)). Each locus is located in/near distinct clusters of OR genes. These findings increase the number of olfactory sensitivity loci to nine and demonstrate the importance of OR-associated variation in sensory acuity for food-related odors. Analysis of genotype frequencies across human populations implies that variation in sensitivity for these odors is widespread. Furthermore, each participant possessed one of many possible combinations of sensitivities for these odors, supporting the notion that everyone experiences their own unique "flavor world."

An ancient duplication of apple MYB transcription factors is responsible for novel red fruit-flesh phenotypes.

Anthocyanin accumulation is coordinated in plants by a number of conserved transcription factors. In apple (Malus × domestica), an R2R3 MYB transcription factor has been shown to control fruit flesh and foliage anthocyanin pigmentation (MYB10) and fruit skin color (MYB1). However, the pattern of expression and allelic variation at these loci does not explain all anthocyanin-related apple phenotypes. One such example is an open-pollinated seedling of cv Sangrado that has green foliage and develops red flesh in the fruit cortex late in maturity. We used methods that combine plant breeding, molecular biology, and genomics to identify duplicated MYB transcription factors that could control this phenotype. We then demonstrated that the red-flesh cortex phenotype is associated with enhanced expression of MYB110a, a paralog of MYB10. Functional characterization of MYB110a showed that it was able to up-regulate anthocyanin biosynthesis in tobacco (Nicotiana tabacum). The chromosomal location of MYB110a is consistent with a whole-genome duplication event that occurred during the evolution of apple within the Maloideae family. Both MYB10 and MYB110a have conserved function in some cultivars, but they differ in their expression pattern and response to fruit maturity.

Estimation of stature from static and dynamic footprints.

The ability to estimate accurately from known parameters is a fundamental aspect of science and is evident as an emerging approach in the area of footprints and stature estimation within the field of forensic identification. There are numerous foot dimensions that have been measured in the literature to predict stature with varying degrees of confidence but few studies have tried to link the strength of estimation to anatomical landmarks. Such an approach is utilised in this study which estimates stature from the right footprints of sixty one adult male and female UK participants. Static and dynamic footprints were taken from each volunteer using the 'inkless paper system'. The prints were digitised and twelve length, width and angle measurements were chosen for the analysis. The highest correlations with stature were shown to be the heel to fourth toe print for the static group of footprints (r=0.786, p<0.01), and the heel to fifth toe print in the dynamic footprints (r=0.858, p<0.01). Collinearity statistics suggest the heel to fifth toe print length measurement is independent and not influenced by any other variables in the estimation of stature for the dynamic prints. Linear regression equations for this measurement presented the smallest standard error of estimate (SEE) and highest shared variance (R(2)) of all included variables (SEE 4.16, R(2) 0.74). Our study discusses a potential anatomical explanation as to why the lateral border of the foot and hence the impression it makes upon a hard surface, is a more stable indicator in the estimation of stature. The investigation recommends the use of Calc_A4 and Calc_A5 length measurements when estimating stature from footprint impressions.

Reliability of a two-dimensional footprint measurement approach.

Although footprint evidence can be taken from the scene of a crime, the science underpinning such measurement in forensic science has not been fully explored. A literature search revealed various measuring approaches, all of which demonstrated either little or no measurement rigour in terms of reliability. The aim of this study was to apply a robust measurement approach for testing the reliability of two-dimensional footprint impressions. Three dynamic and three static footprints were taken from the right foot of thirty female and thirty one male volunteers using the 'Inkless Shoeprint Kit'. The images were digitised. Lengths, widths and angles were measured using a selection of currently employed methods. An investigation of the reliability of the chosen measuring method suggested high intra-rater agreement: for example, the length measurement suggested an intraclass correlation coefficient (ICC) 0.99, 95% Confidence Interval (CI) -0.28 to 0.01, standard error of measurement (SEM) 0.07, Limits of Agreement (LOA) -0.91 to 0.65. Inter-rater reliability between three operators was also high: SEM ranged from 0.05 mm to 0.07 mm, ICC 0.99. Our study has established a reliable two-dimensional measuring technique that could be used for footprint comparison in further research.