The Interplay between Natural Selection and Susceptibility to Melanoma on Allele 374F of SLC45A2 Gene in a South European Population

We aimed to study the selective pressures interacting on SLC45A2 to investigate the interplay between selection and susceptibility to disease. Thus, we enrolled 500 volunteers from a geographically limited population (Basques from the North of Spain) and by resequencing the whole coding region and intron 5 of the 34 most and the 34 least pigmented individuals according to the reflectance distribution, we observed that the polymorphism Leu374Phe (L374F, rs16891982) was statistically associated with skin color variability within this sample. In particular, allele 374F was significantly more frequent among the individuals with lighter skin. Further genotyping an independent set of 558 individuals of a geographically wider population with known ancestry in the Spanish population also revealed that the frequency of L374F was significantly correlated with the incident UV radiation intensity. Selection tests suggest that allele 374F is being positively selected in South Europeans, thus indicating that depigmentation is an adaptive process. Interestingly, by genotyping 119 melanoma samples, we show that this variant is also associated with an increased susceptibility to melanoma in our populations. The ultimate driving force for this adaptation is unknown, but it is compatible with the vitamin D hypothesis. This shows that molecular evolution analysis can be used as a useful technology to predict phenotypic and biomedical consequences in humans.

Orígenes indoeuropeos (y no indoeuropeos) de la vocal [y] eslava

[ES] La vocal 'y' de las lenguas eslavas procede esencialmente de i.e. *ū. Pero en el dominio de la flexión tanto nominal como verbal se puede encontrar asimismo una vocal 'y' de origen intraeslavo y derivada de diversas secuencias en final de palabra. Al estudio de estas evoluciones así como al análisis de los distintos estratos de préstamos léxicos que incrementan la presencia de la vocal y en el léxico eslavo se dedica buena parte de este trabajo. En él se rastrean, además, los datos comparativos e internos que permiten detectar otro origen para la vocal eslava 'y' los diptongos i.e. *ou y *au.

Teen-age identity construction in Stephen King: A gendered view

280 p.