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A retrospective, quantitative, long-term evaluation of patients with a free flap transfer to the lower extremity was carried out with respect to functional, socioeconomic, and esthetic outcome. The study included 57 patients who were examined by questionnaire filled out by both an examiner and the patients themselves. Indications for the free flaps were acute trauma or osteomyelitis and unstable scars arising from a previous trauma to the lower leg. The flap success rate was 94.7%. The period between the operation and evaluation was at least 3years. A local, flap-specific functional impairment was found in 17 patients (30%) and a general impairment of the lower extremity in 56% of the subjects. With respect to the socioeconomic outcome more than two-thirds of the patients returned to their previous occupation with no restrictions; approximately 20% of subjects had to switch to a less strenuous job. Although from the viewpoint of the examiner the esthetic appearance was satisfactory in 44 free flaps (77%), the majority of the patients were conscious of pigmental, textural, or contour changes which produced a subjective esthetic compromise in 56% of cases. In conclusion, despite a considerably high rate of local functional impairment the majority of patients (89%) were satisfied and judged the application of a free flap as having been beneficial in preventing a loss in socioeconomic status. The high rate of esthetic problems demonstrates the importance of including esthetic considerations in designing the free flap, in particular with regard to (a) meticulously tailoring the flap, (b) aiming at a homogeneous skin surface, and (c) thoroughly shaping the affected lower extremity

The extent of pleiotropy and epistasis in quantitative traits remains equivocal. In the case of pleiotropy, multiple quantitative trait loci are often taken to be pleiotropic if their confidence intervals overlap, without formal statistical tests being used to ascertain if these overlapping loci are statistically significantly pleiotropic. Additionally, the degree to which the genetic correlations between phenotypic traits are reflected in these pleiotropic quantitative trait loci is often variable, especially in the case of antagonistic pleiotropy. Similarly, the extent of epistasis in various morphological, behavioural and life-history traits is also debated, with a general problem being the sample sizes required to detect such effects. Domestication involves a large number of trade-offs, which are reflected in numerous behavioural, morphological and life-history traits which have evolved as a consequence of adaptation to selective pressures exerted by humans and captivity. The comparison between wild and domestic animals allows the genetic analysis of the traits that differ between these population types, as well as being a general model of evolution. Using a large F(2) intercross between wild and domesticated chickens, in combination with a dense SNP and microsatellite marker map, both pleiotropy and epistasis were analysed. The majority of traits were found to segregate in 11 tight 'blocks' and reflected the trade-offs associated with domestication. These blocks were shown to have a pleiotropic 'core' surrounded by more loosely linked loci. In contrast, epistatic interactions were almost entirely absent, with only six pairs identified over all traits analysed. These results give insights both into the extent of such blocks in evolution and the development of domestication itself.

Egg and production traits are of considerable economic importance in chickens. Using a White Leghorn x red junglefowl F-2 intercross, standard production measures of liver weight and colour, egg size, eggshell thickness, egg taste and meat quality were taken. A total of 160 markers covering 29 autosomes and the Z chromosome were genotyped on 175-243 individuals, depending on the trait under consideration. A total of nine significant quantitative trait loci (QTL) and three suggestive QTL were found on chicken chromosomes 1, 2, 4, 5, 7, 8, 10, 12, E47W24 and E22C19W28.

A large intercross between the domestic White Leghorn chicken and the wild ancestor, the red junglefowl, has been used in a Quantitative Trait Loci (QTL) study of growth and egg production. The linkage map based on 105 marker loci was in good agreement with the chicken consensus map. The growth of the 851 F2 individuals was lower than both parental lines prior to 46 days of age and intermediate to the two parental lines thereafter. The QTL analysis of growth traits revealed 13 loci that showed genome-wide significance. The four major growth QTLs explained 50 and 80% of the difference in adult body weight between the founder populations for females and males, respectively. A major QTL for growth, located on chromosome 1 appears to have pleiotropic effects on feed consumption, egg production and behaviour. There was a strong positive correlation between adult body weight and average egg weight. However, three QTLs affecting average egg weight but not body weight were identified. An interesting observation was that the estimated effects for the four major growth QTLs all indicated a codominant inheritance.