Project description:MicroRNAs (miRNAs) are emerging as essential, albeit poorly characterized, regulators of biological processes. The miRNA in gymnosperms is under-identified, which limits the progress of miRNA in gymnoperms. Using the high-throughput sequencing, a total of 87 conserved miRNAs were identified from Larix leptolepis. Eighteen novel miRNAs were discovered in our library, most of which were Larix-specific miRNAs.
Project description:MicroRNAs (miRNAs) are emerging as essential, albeit poorly characterized, regulators of biological processes. The miRNA in gymnosperms is under-identified, which limits the progress of miRNA in gymnoperms. Using the high-throughput sequencing, a total of 87 conserved miRNAs were identified from Larix leptolepis. Eighteen novel miRNAs were discovered in our library, most of which were Larix-specific miRNAs. Identification of small RNA in Larix seedling
Project description:Low-pass sequencing (sequencing a genome to an average depth less than 1× coverage) combined with genotype imputation has been proposed as an alternative to genotyping arrays for trait mapping and calculation of polygenic scores. To empirically assess the relative performance of these technologies for different applications, we performed low-pass sequencing (targeting coverage levels of 0.5× and 1×) and array genotyping (using the Illumina Global Screening Array (GSA)) on 120 DNA samples derived from African and European-ancestry individuals that are part of the 1000 Genomes Project. We then imputed both the sequencing data and the genotyping array data to the 1000 Genomes Phase 3 haplotype reference panel using a leave- one-out design. We evaluated overall imputation accuracy from these different assays as well as overall power for GWAS from imputed data, and computed polygenic risk scores for coronary artery disease and breast cancer using previously derived weights. We conclude that low-pass sequencing plus imputation, in addition to providing a substantial increase in statistical power for genome wide association studies, provides increased accuracy for polygenic risk prediction at effective coverages of ∼ 0.5× and higher compared to the Illumina GSA.
Project description:Following the dispersal out of Africa, where hominins evolved in warm environments for millions of years, our species has colonised different climate zones of the world, including high latitudes and cold environments. The extent to which human habitation in (sub-)Arctic regions has been enabled by cultural buffering, short-term acclimatization and genetic adaptations is not clearly understood. Present day indigenous populations of Siberia show a number of phenotypic features, such as increased basal metabolic rate, low serum lipid levels, increased blood pressure, short stature and broad skulls that have been attributed to adaptation to the extreme cold climate. We have genotyped 200 individuals from ten indigenous Siberian populations for 730,525 SNPs across the genome to identify genes and non-coding regions that have undergone unusually rapid allele frequency and long-range haplotype homozygosity change in the recent past. At least three distinct population clusters could be identified among the Siberians, each of which showed a number of unique signals of selection. We present a list of cold adaption candidate genes that showed significant signals of positive selection with our strongest signals associated with genes involved in energy regulation and metabolism (CPT1A, LRP5, THADA) and vascular smooth muscle contraction (PRKG1). By employing a new method that paints phased chromosome chunks by their ancestry we distinguish local Siberian-specific long-range haplotype signals from those introduced by admixture. 200 blood samples from 200 Siberian individuals that come from ten different indigenous populations were genotypes for 730,525 SNPs across the genome. Eighteen Vietnamese samples were also genotyped and used as reference samples.