Project description:MEFs were infected with Oct4, Sox2, Klf4 (+/- Sall4), sorted for miR-290/302 reporter expression at day 9 (OSK) or 12 (Sall4+OSK), and then profiled. Resulting iPSCs were also profiled. Mouse ES cells were differentiated and sorted for miR-290/302 reporter expression during Fgf/Activin differentiation (day 4 or day 7).
Project description:MEFs were infected with Oct4, Sox2, Klf4 (+/- Sall4), sorted for miR-290/302 reporter expression at day 9 (OSK) or 12 (Sall4+OSK), and then profiled. Resulting iPSCs were also profiled. Mouse ES cells were differentiated and sorted for miR-290/302 reporter expression during Fgf/Activin differentiation (day 4 or day 7). Performed in biological triplicate. Biological triplicate samples represent three independent lines. Total RNA collected with Trizol. All processing conducted at the UCLA Neuroscience Genomics Core. MouseRef-8 v2.0 Expression BeadChips.
Project description:The miR-290 and miR-302 clusters of microRNAs are highly expressed in naïve and primed pluripotent stem cells, respectively. Ectopic expression of the embryonic stem cell-specific cell cycle regulating (ESCC) family of microRNAs arising from these two clusters dramatically enhances the reprogramming of both mouse and human somatic cells to induced pluripotency. Here, we used genetic knockouts to dissect the requirement for the miR-290 and miR-302 clusters during the reprogramming of mouse fibroblasts into induced pluripotent stem cells (iPSCs) with retrovirally introduced Oct4, Sox2, and Klf4. Knockout of either cluster alone did not negatively impact the efficiency of reprogramming. Resulting cells appeared identical to their embryonic stem cell counterparts. Notably miR-290 knockout cells showed a compensatory increase in miR-302 expression and the combined loss of both clusters blocked the formation of iPSCs. While rare double knockout clones could be isolated, they showed a dramatically reduced proliferation rate, a persistent inability to fully silence the exogenously introduced pluripotency factors, and a transcriptome distinct from individual miR-290 or miR-302 mutant ESC and iPSCs. Taken together, our data show that miR-290 and miR-302 are essential yet interchangeable in reprograming to the induced pluripotent state.
Project description:A family of vertebrate-specific microRNAs called the ESCC microRNAs regulates proliferation and differentiation of embryonic stem cells. The ESCC microRNAs arise from two genetic loci in mammals, the miR-290/miR-371 and miR-302 loci. While the miR-302 locus is found broadly among vertebrates, the miR-290/miR-371 locus is unique to eutherian species, suggesting a role in placental development. Here, we evaluate that role. A knockin reporter for the mouse miR-290 gene is expressed throughout the embryo until gastrulation, at which time it becomes specifically expressed in extraembryonic tissues and the germline. In the placenta, expression is limited to the trophoblast lineage, where it remains highly expressed until birth. Deletion of the miR-290 gene results in reduced trophoblast progenitor cell proliferation and a reduced DNA content in endoreduplicating trophoblast giant cells. A reduction in placental size precedes a reduction in fetal size and prenatal death of most knockout embryos. The vascular labyrinth shows disorganization with thickening of the barrier between maternal and fetal blood associated with reduced diffusion of a radioactive tracer. Multiple mRNA targets of the cluster miRNAs are upregulated. Together, these data uncover a critical function for the miR-290 in the regulation of a network of genes required for normal placental development, suggesting a central role for this microRNA cluster in the evolution of eutherian species.
Project description:Study designed to determine the immediate effects of supplementing OSK reprogramming with miR-294 or miR-181. MEFs were infected on day 0, and transfected with miR-294, miR-181 or control mimic on day 1. On day 3 RNA was extracted. OSK infected MEFs samples were compared to non-infected MEFs and to fully reprogrammed iPSCs.
Project description:Study designed to determine the immediate effects of supplementing OSK reprogramming with miR-294 or miR-181. MEFs were infected on day 0, and transfected with miR-294, miR-181 or control mimic on day 1. On day 3 RNA was extracted. OSK infected MEFs samples were compared to non-infected MEFs and to fully reprogrammed iPSCs. Performed in biological triplicate, with each sample containing different OSK viral stocks, different preparations of MEFs and independent transfections. Biological triplicate iPSCs represent three independent and clonally expanded iPSC lines. Total RNA collected with Trizol. All processing conducted at the UCLA Neuroscience Genomics Core. MouseRef-8 v2.0 Expression BeadChips.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.