title: Impact of microRNA regulation on variation in human gene expression.
abstract: MicroRNAs (miRNAs) are endogenously expressed small RNAs that regulate expression of mRNAs at the post-transcriptional level. The consequence of miRNA regulation is hypothesized to reduce the expression variation of target genes. However, it is possible that mutations in miRNAs and target sites cause rewiring of the miRNA regulatory networks resulting in increased variation in gene expression. By examining variation in gene expression patterns in human populations and between human and other primate species, we find that miRNAs have stabilized expression of a small number of target genes during primate evolution. Compared with genes not regulated by miRNAs, however, genes regulated by miRNAs overall have higher expression variation at the population level, and they display greater variation in expression among human ethnic groups or between human and other primate species. By integrating expression data with genotypes determined in the HapMap 3 and the 1000 Genomes Projects, we found that expression variation in miRNAs, genetic variants in miRNA loci, and mutations in miRNA target sites are important sources of elevated expression variation of miRNA target genes. A reasonable case can be made that natural selection is driving this pattern of variation.
authors.affiliation: Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA. JL2434@cornell.edu
authors.forename: Jian
authors.initials: J
authors.lastname: Lu
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Clark
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D005006:Ethnicity / Q000235:genetics; D019143:Evolution, Molecular; D005786:Gene Expression Regulation; D053263:Gene Regulatory Networks; D056426:Genetic Loci; D005828:Genetics, Population / Q000379:methods; D015894:Genome, Human; D005838:Genotype; D060005:Genotyping Techniques / Q000379:methods; D060148:HapMap Project; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods; D016045:Human Genome Project; D006801:Humans; D007962:Leukocytes / Q000166:cytology / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012641:Selection, Genetic; D013045:Species Specificity
chemical_list: D035683:MicroRNAs; D012333:RNA, Messenger