EHJ352H1 Lecture Notes - Lecture 4: Abo Blood Group System, Epas1, Selective Sweep
12 Oct 2016
School
Department
Course
Professor
Document Summary
Reproduction: sperm motility, sperm and egg viability, female immune response to sperm. Skin pigmentation: four genes show evidence for recent positive selection in european populations. Diet: carbohydrate metabolism, processing of fatty acids. Increased differentiation among populations: test is best applied if you have closely related populations, ex. Epas1 gene is an outlier - specifically very high branch statistic in tibet. Tibet has an unusually high allele frequency at epas1 genes compared to han sample and other groups. Associated with lower haemoglobin and lower erythrocyte counts at high elevation. Populations who aren"t used to high elevation go into an acute response leading to epas1 activation. If the population is always at a high elevation, this acute response could cause chronic problems - populations that have adapted to high elevation have down regulated this epas1 gene so that they can survive at high elevation. Neutral variation is reduced with positive selection.
