The Main Determinant of Cellular Phenotypes is the Expression of Genes. Understanding how this can vary in human populations is a vital part of biomedical research. The Phenotypic differences observed in populations can arise from genetic and non genetic factors such as differing environments. A recent study tested these factors by investigating the proportion of European Ancestry in individuals through genetic analysis. The research led by Alkes L. Price of the Harvard School of Public Health in Boston, Massachusetts claimed that the research of one population of African Americans could minimize the idea of non genetic factors influencing the expression of genes. Various researchers have attempted to take advantage of this concept, proving that a variety of phenotypic traits can differ in levels of expression according to the proportion of European ancestry.
The research examined lymphoblastoid cell lines from eighty-nine African-American samples and investigated the relationship between expression levels of 4200 genes and the proportion of European ancestry. These were then compared to the results of sixty European samples and sixty African samples which also exhibited differences in expression levels of genes. The results confirmed the possibility of gene expression differences. This showed a significant correspondence between the trial comparing the levels of gene expression in European and African Samples and the trial comparing the gene expression of a population of African Americans.
“This suggests that the effects of heritable population differences on variation in gene expression are widespread across genes, mirroring population differences at the DNA level”
(Greg Gibson, 2008)
The results demonstrated that numbers of genes expressed in continental populations had significant differences. This reaffirmed the hypothesis that the differences in gene expression were correlated to the ancestry of an admixed population. Studies in the past had attempted to map these differences which result from Cis and Trans effects but few studies have actually released results due to low sample sizes. The study concluded from evidence gathered that only 12% of variation in the expression of human genes was due to cis-regulation.
References
Greg Gibson (5/12/2008) Effects of cis and trans Genetic Ancestry on Gene Expression in African Americans (http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1000294) [Accessed 24/03/09]
Public Library of Science (6/12/2008) Genetic Ancestry Of African-Americans Reveals New Insights About Gene Expression (http://www.sciencedaily.com/releases/2008/12/081205094513.htm) [Accessed 24/03/09]
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By Student 42000327
