Africa is the site of origin of modern humans, contains the greatest levels of human genomic
variation, and is the source of the worldwide range expansion of modern humans in the past
100,000 years. However, a fundamental gap in knowledge exists regarding African genomic and
phenotypic variation, resulting in a lag in biomedical research, not only in Africans, but also in
people of recent African descent. We will apply an integrative evolutionary genomics approach
incorporating genomic, metabolomic, microbiome, epigenomic, and transcriptomic data in
combination with detailed phenotypic data to reconstruct African population history and better
understand the genetic basis of adaptive traits in ethnically diverse African populations.
Specifically, we will use genome-wide SNP arrays as well as high-coverage whole genome
sequencing data to identify targets of natural selection in these populations and to look for genetic
associations with gene expression as well as anthropometric, cardio-metabolic, and immune
related traits. We will use functional genomics approaches to identify causal regulatory loci and
to study their impact on gene expression in vitro using high-throughput luciferase reporter assays
in appropriate cell lines. We will also use Crispr-Cas9 technology to validate and characterize the
functional impact of potential casual variants in both human cells and in vivo in model systems.
Lastly, we will characterize gut microbiome diversity and examine correlations with diet, genetic
and environmental variation. Our data will generate a deeper understanding of African genomic
diversity, population structure, and patterns of linkage disequilibrium that are critical for the
successful application and interpretation of genome wide association studies in African-descent
populations. Furthermore, this study will have important implications for understanding the genetic
basis of intermediate phenotypes (gene expression and the metabolome) and of complex traits in
Africans. In addition, the data collected will be an important resource for the biomedical research
community. Lastly, our study will shed light on human evolutionary history and evolutionary forces
shaping patterns of genomic variation in ethnically diverse humans.