Project description:DNA methylation data from Papio hamadryas (baboons) profiled on the mammalian methylation array (HorvathMammalMethylChip40) which focuses on highly conserved CpGs across mammalian species. Seven tissue types (fetal cerebral cortex, adult cerebral cortex, cerebellum, adipose, heart, liver, and skeletal muscle) with ages ranging from late fetal life to 22.8 years of age.
Project description:Primate evolution has been argued to result, in part, from changes in how genes are regulated. However, we still know little about gene regulation in natural primate populations. We conducted an RNA sequencing (RNA-seq)-based study of baboons from an intensively studied wild population. We performed complementary expression quantitative trait locus (eQTL) mapping and allele-specific expression analyses, discovering substantial evidence for, and surprising power to detect, genetic effects on gene expression levels in the baboons. eQTL were most likely to be identified for lineage-specific, rapidly evolving genes; interestingly, genes with eQTL significantly overlapped between baboons and a comparable human eQTL data set. Our results suggest that genes vary in their tolerance of genetic perturbation, and that this property may be conserved across species. Further, they establish the feasibility of eQTL mapping using RNA-seq data alone, and represent an important step towards understanding the genetic architecture of gene expression in primates. 63 samples (1 per individual) from a wild population of baboons to understand genetic contributions to population variance in gene expression levels
Project description:Dysregulation of microRNAs (miRNAs) expression has been implicated in molecular genetics events leading to the progression and development of atherosclerosis. We hypothesized that miRNA expression profiles differ between baboons with low and high serum low-density lipoprotein cholesterol (LDL-C) concentrations in response to diet, and that a subset of these miRNAs regulate genes relevant to dyslipidemia and risk of atherosclerosis. We generated small RNA libraries from baboons differing in their LDL-C response to dietary fat and cholesterol (low LDL-C, n = 3; high LDL-C, n = 3) using liver biopsies collected before and after a high-cholesterol, high-fat (HCHF) challenge diet. We sequenced the libraries using Next-Generation Illumina sequencing methods, analyzed the data using mirTools software and identified 517 baboon miRNAs: 490 homologous to human and 27 novel miRNAs. HCHF diet elicited expression of more miRNAs compared to baseline (chow) diet for both low and high LDL-C baboons. Seventeen miRNAs exhibited significant differential expression in response to HCHF diet in high LDL-C baboons compared to nine miRNAs in low LDL-C baboons. Putative miRNA targets were identified with TargetScan/Base tools. miRNAs significantly targeted more genes in high LDL-C baboons compared to low LDL-C responders. Further, we identified miRNA isomers and other non-coding RNAs that were differentially expressed in response to the challenge diet.Our discovery of differentially expressed baboon miRNAs and their targets is a fundamental step in understanding the role of non-coding RNAs in the modulation of dsylipidemia.