News from IBE (CSIC-UPF) and CEXS-UPF
Drawing from population genomics, ancient DNA research and in vitro cellular zinc uptake experiments, an exciting study related to the micronutrient zinc in Sub-Saharan African populations has just been published in PLOS Genetics.
In this study, one of the strongest signals of positive natural selection worldwide was characterized. This genomic signal had been overlooked so far as it was hidden by the effects of a recombination hotspot. Experimentally, an amino acid replacement in the human intestinal zinc uptake transporter ZIP4 was shown to lead to reduced zinc uptake in the African isoform. Curiously, the same amino acid position harbors rare mutations for a heritable disease of extreme zinc deficiency (Acrodermatitis enteropathica).
Now the jury is out for the next step, namely confirming the likely selective force and phenotypes in this adaptive event: Could this be resistance to malaria or to some other pathogen? And in today´s worldwide populations, may this variant have an effect on organismal zinc levels?
The study was led by IBE researchers from the Elena Bosch Lab in collaboration with researchers from the Molecular Physiology and Channelopathies Group at DCEXS (UPF).
Engelkhen et al. "Extreme Population Differences in the Human Zinc Transporter ZIP4 (SLC39A4) Are Explained by Positive Selection in Sub-Saharan Africa", (2014) PLOS Genetics, 20 de febrer, http://www.plosgenetics.org/doi/pgen.1004128