Author Interviews, Genetic Research / 24.10.2014
Genes Beneficial To Our Ancestors, May Be Harmful Today
MedicalResearch.com Interview with:
Dr. Toomas Kivsild PhD
Department of Archaeology and Anthropology
University of Cambridge, Cambridge
Medical Research: What is the background for this study? What are the main findings?
Dr. Kivsild: Native populations of Siberia are known to have certain physiological
characteristics such as high basal metabolic
rate, and high blood pressure and low levels of serum lipids, that have
been explained as traits that have evolved
as a consequence of the adaptation of Siberians to their cold
environment. Genetic basis of cold adaptation is still poorly understood.
In our previous study using genome-wide genotyping scans we detected a 3
Mbp region of high haplotype homozygosity in chromosome 11 as a
candidate of strong positive selection in Northeast Siberians.
There were 79 protein coding genes mapping to this homozygosity region
but we could not determine which of the genes
was driving the signal we observed.
In this forthcoming paper we have used high coverage whole genome
sequences from 25 individuals from Northeast Siberia and we were able
to determine the most likely SNP that is responsible for the high
haplotype homozygosity in the chromosome 11 in Northeast Siberians maps
to CPT1A gene which is a key regulator of long-chain fatty-acid
oxidation in mitochondria. What makes this finding most interesting is
that the same SNP had previously been found in Greenland and Canadian
Inuits in association with high infant mortality and hypoketotic
hypoglycemia. There are only a few other similar cases, like the sickle
cell and APOL1 alleles, where disease associated genetic variants may
have risen to high frequency in modern day populations due to the
adaptive advantage they have presented in the past populations.
(more…)