| geographical structuring in the mtdna of italians. | geographical patterns of mtdna variation were studied in 12 italian samples (1072 individuals) by two different spatial autocorrelation methods. separate analyses of the frequencies of 12 restriction morphs show north-south clines, differences between sardinia and the mainland populations, and the effects of isolation by distance. a recently developed autocorrelation statistic summarizing molecular similarity at all sites (aida; autocorrelation index for dna analysis) confirms the presence of a ... | 1995 | 7568095 |
| apolipoprotein e polymorphism in italy investigated in native plasma by a simple polyacrylamide gel isoelectric focusing technique. comparison with frequency data of other european populations. | a new polyacrylamide gel isoelectric focusing (pagief) technique has been developed that allows rapid and reliable identification of apolipoprotein e (apoe) phenotypes directly from plasma or serum without any prior treatment. this method was used to determine the apoe phenotypes in samples from central and southern italy, sicily, and sardinia. the frequencies observed for the apoe*2, apoe*3, and apoe*4 alleles in central and southern italy (sicily included) were similar (0.066, 0.851, 0.083 and ... | 1995 | 7625766 |
| population structure of sicily: beta-thalassemia and hbs. | the population structure of two alleles with similar characteristics, hbs and beta-thalassemia, was studied in the same area in sicily. it was observed that beta-thalassemia has uniform frequencies over the island, and that hbs shows a south-north cline. a singularity exists for hbs in the town of butera, where the frequency of the s gene is six times higher than the island average. it was suggested that hbs entered sicily from greece (or directly from north africa) when the beta-thalassemia all ... | 1987 | 3804326 |
| adaptation and selection in the senecio (asteraceae) hybrid zone on mount etna, sicily. | hybrid zone theory provides a powerful theoretical framework for measuring and testing gene flow and selection. the senecio aethnensis and senecio chrysanthemifolius hybrid zone on mount etna, sicily, was investigated to identify phenotypic traits under divergent selection and to assess the contributions of intrinsic and extrinsic selection against hybrids to hybrid zone maintenance. senecio samples from 14 sites across mount etna were analyzed for 24 quantitative traits classified into four gro ... | 2009 | 19594693 |
| exogenous selection shapes germination behaviour and seedling traits of populations at different altitudes in a senecio hybrid zone. | the senecio hybrid zone on mt etna, sicily, is characterized by steep altitudinal clines in quantitative traits and genetic variation. such clines are thought to be maintained by a combination of 'endogenous' selection arising from genetic incompatibilities and environment-dependent 'exogenous' selection leading to local adaptation. here, the hypothesis was tested that local adaptation to the altitudinal temperature gradient contributes to maintaining divergence between the parental species, s. ... | 2012 | 23071216 |
| recent ecological selection on regulatory divergence is shaping clinal variation in senecio on mount etna. | the hybrid zone on mount etna (sicily) between senecio aethnensis and senecio chrysanthemifolius (two morphologically and physiologically distinct species) is a classic example of an altitudinal cline. hybridization at intermediate altitudes and gradients in phenotypic and life-history traits occur along altitudinal transects of the volcano. the cline is considered to be a good example of ecological selection with species differences arising by divergent selection opposing gene flow. however, th ... | 2013 | 24094352 |