Project description:miRNA-mediated gene expression silencing has previously been shown to be important for a variety of physiological and pathological processes. Here, we have explored the role of one bona fide human-specific miRNA (miR-941) in evolution of the human-specific expression and function. Using combination of high-throughput sequencing (GSE26545), miRNA transfection and large-scale PCR of various human populations, we have shown that emergence and rapid expansion of miR-941 might take place on the human evolutionary linage between six and one million years ago. Functionally, miR-941 could be associated with hedgehog and insulin signaling pathways, and thus might potentially play a role in evolution of human longevity. Human-specific effects of miR-941 regulation are detectable in human brain and affect genes involved in neurotransmitter signaling. Furthermore, emergence of miR-941 on the human evolutionary linage was accompanied by the accelerated loss of its binding sites. Taken together, these results strongly implicate the contribution of miR-941 in evolution of the human-specific phenotype. Cerebellum mRNA samples from 5 human, 5 chimpanzee and 1 rhesus macaque for Affymetrix Human Exon 1.0 ST Arrays were prepared following the standard GeneChip Whole Transcript (WT) Sense Target Labelling Assay.
Project description:miRNA-mediated gene expression silencing has previously been shown to be important for a variety of physiological and pathological processes. Here, we have explored the role of one bona fide human-specific miRNA (miR-941) in evolution of the human-specific expression and function. Using combination of high-throughput sequencing (GSE26545), miRNA transfection and large-scale PCR of various human populations, we have shown that emergence and rapid expansion of miR-941 might take place on the human evolutionary linage between six and one million years ago. Functionally, miR-941 could be associated with hedgehog and insulin signaling pathways, and thus might potentially play a role in evolution of human longevity. Human-specific effects of miR-941 regulation are detectable in human brain and affect genes involved in neurotransmitter signaling. Furthermore, emergence of miR-941 on the human evolutionary linage was accompanied by the accelerated loss of its binding sites. Taken together, these results strongly implicate the contribution of miR-941 in evolution of the human-specific phenotype.
Project description:miRNA-mediated gene expression silencing has previously been shown to be important for a variety of physiological and pathological processes. Here, we have explored the role of one bona fide human-specific miRNA (miR-941) in evolution of the human-specific expression and function. Using combination of high-throughput sequencing (GSE26545), miRNA transfection and large-scale PCR of various human populations, we have shown that emergence and rapid expansion of miR-941 might take place on the human evolutionary linage between six and one million years ago. Functionally, miR-941 could be associated with hedgehog and insulin signaling pathways, and thus might potentially play a role in evolution of human longevity. Human-specific effects of miR-941 regulation are detectable in human brain and affect genes involved in neurotransmitter signaling. Furthermore, emergence of miR-941 on the human evolutionary linage was accompanied by the accelerated loss of its binding sites. Taken together, these results strongly implicate the contribution of miR-941 in evolution of the human-specific phenotype.
Project description:miRNA-mediated gene expression silencing has previously been shown to be important for a variety of physiological and pathological processes. Here, we have explored the role of one bona fide human-specific miRNA (miR-941) in evolution of the human-specific expression and function. Using combination of high-throughput sequencing (GSE26545), miRNA transfection and large-scale PCR of various human populations, we have shown that emergence and rapid expansion of miR-941 might take place on the human evolutionary linage between six and one million years ago. Functionally, miR-941 could be associated with hedgehog and insulin signaling pathways, and thus might potentially play a role in evolution of human longevity. Human-specific effects of miR-941 regulation are detectable in human brain and affect genes involved in neurotransmitter signaling. Furthermore, emergence of miR-941 on the human evolutionary linage was accompanied by the accelerated loss of its binding sites. Taken together, these results strongly implicate the contribution of miR-941 in evolution of the human-specific phenotype.
Project description:miRNA-mediated gene expression silencing has previously been shown to be important for a variety of physiological and pathological processes. Here, we have explored the role of one bona fide human-specific miRNA (miR-941) in evolution of the human-specific expression and function. Using combination of high-throughput sequencing (GSE26545), miRNA transfection and large-scale PCR of various human populations, we have shown that emergence and rapid expansion of miR-941 might take place on the human evolutionary linage between six and one million years ago. Functionally, miR-941 could be associated with hedgehog and insulin signaling pathways, and thus might potentially play a role in evolution of human longevity. Human-specific effects of miR-941 regulation are detectable in human brain and affect genes involved in neurotransmitter signaling. Furthermore, emergence of miR-941 on the human evolutionary linage was accompanied by the accelerated loss of its binding sites. Taken together, these results strongly implicate the contribution of miR-941 in evolution of the human-specific phenotype. Ago2 Immunoprecipitation (Ago2-IP) experiments after miR-941 overexpression were conducted in 293T cell line. Briefly, All transfections were performed using human 293T cells cultured in 6-well tissue culture plates. Lipofectamine 2000 (Invitrogen) was used for a Synthetic miR-941 or a scrambled oligo transfection, at 30 nmol/l each (final concentration) per 1x106 cells/well of a 6-well plate using DharmaFECT (GE Healthcare). Total 5x106 cells were collected and subjected to Ago2 immunoprecipitation (Ago2-IP) using the RNA isolation kit Mouse Ago2 (Wako Chemicals) according to the manufacturer's instructions. For a negative control, immunoprecipitation was performed using nonimmune IgG beads prepared with the antibody immobilization bead kit (Wako Chemicals). The IP pull down RNA was used as template for an “in vitro” transcription reaction generating biotin-labeled antisense cRNA. The cRNA was analyzed on affymetrix Human Genome U133 Plus 2.0 arrays following the manufacturer’s instructions. R RMA package was used to quantify gene expression levels.
Project description:miRNA-mediated gene expression silencing has previously been shown to be important for a variety of physiological and pathological processes. Here, we have explored the role of one bona fide human-specific miRNA (miR-941) in evolution of the human-specific expression and function. Using combination of high-throughput sequencing (GSE26545), miRNA transfection and large-scale PCR of various human populations, we have shown that emergence and rapid expansion of miR-941 might take place on the human evolutionary linage between six and one million years ago. Functionally, miR-941 could be associated with hedgehog and insulin signaling pathways, and thus might potentially play a role in evolution of human longevity. Human-specific effects of miR-941 regulation are detectable in human brain and affect genes involved in neurotransmitter signaling. Furthermore, emergence of miR-941 on the human evolutionary linage was accompanied by the accelerated loss of its binding sites. Taken together, these results strongly implicate the contribution of miR-941 in evolution of the human-specific phenotype. miRNA transfection experiments were conducted in 6 cell lines: two human derived kidney cell lines (HEK and 293T), one human skin fibroblast cell line (HSF2), two macaque derived kidney cell lines (LLCMK2 and FrhK-4), and one macaque skin fibroblast cell line (MSF). Briefly, cells were plated in 0.5 ml of growth medium 24h prior to transfection without antibiotics. miR-941 mimics-Lipofectamine 2000 (Invitrogen) complexes were prepared freshly before transfection based on the manufacturer’s protocol. Cells were transfected in six-well plates using miRNA mimics-Lipofectamine 2000 with a final oligonucleotide concentration of 10nmol/L. In parallel, negative control transfections with mock oligonucleotides were conducted according to the manufacturer’s protocol. After 24h, cells were harvested and total RNA were extracted using Trizol reagent (Invitrogen) and further processed and hybridized to Affymetrix Human Genome U133 Plus 2.0 arrays following the manufacturer’s instructions. The R RMA package was used to quantify gene expression levels.
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes