Project description:Murine long-term hematopoietic stem cells (HSCs), short-term HSCs and multipotent progenitor cells (MPPs) were isolated from bone marrow and expression profiled on Affy chips. The behavior of maternal-specific imprinting genes, particularly in the H19-Igf2 locus, was focused on, to see if any might be involved in maintaining quiescence of long-term stem cells.
Project description:Long-term hematopoietic stem cells (HSCs), short-term HSCs and multipotent progenitor cells (MPPs) were isolated from bone marrow of four mouse strains (WT, H19-deletion, Igf1r-deletion, and double-deletion) and expression profiled with RNAseq. The behavior of the transcriptomes, and in particular the imprinted genes, was analyzed to see what might be involved in maintaining quiescence of long-term stem cells, and how H19 and Igf1r affected the expression of imprinted genes. Transcriptional profiling data of the same cells have been deposited in ArrayExpress under accession number E-MTAB-1644 (http://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-1644/).
Project description:Clear cell renal cell carcinoma (ccRCC) initiated from the renal epithelium is the most prevalent histological type of adult kidney cancers. Dissecting intratumoral heterogeneity (ITH) of ccRCC has leveraged to extend our knowledge on how primary tumors harboring driver mutations evolve and spread to other sites. The cellular fractions within and across the primary (pRCC) and metastatic RCC (mRCC) are heterogeneous in both their genetic and biological features determining the variability in clinical aggressiveness and sensitivity to the therapy. To achieve sustainable therapeutic benefit with targeted agents in mRCC, the effective target should focus on signaling pathways that are related to driver mutations occurred early in the clonal evolution of the disease and thus should be common to primary tumor and metastatic sites. Considering that extensive genetic heterogeneity may result in drug response variability among patients and treatment resistance, the tailored strategies for metastatic RCC is urgently needed. Here, we analyze single-cell RNA-seq (scRNA-seq) data from a matched primary RCC (pRCC) and lung metastasis (mRCC) to dissect ITH at the highest resolution to date with the objective of discovering the better therapeutic regimen. In order to identify successful clonal propagation from patient to PDX samples and understand pathogenesis from primary to metastatic RCC, we performed whole-exome sequencing (WES, n=4) and matched aCGH (n=4) on bulk tumor samples. And we utilized single-cell RNA sequencing (scRNA-seq) to model and dissect functional heterogeneity acroass primary and metastatic RCC tumors. We checked whether of capturing live one cell, not more cells, in microfluidics by fluorescent microscopic observation. To construct RNA sequencing libraries, we performed further quality controls including adequate quantities and qualities of amplified transcriptomes respectively from single cells. Tumor cells from the parental mRCC (n=34), PDX-mRCC (n=36) and PDX-pRCC (n=46) were finally analyzed in this study after filtering out poor quality cells.
Project description:PIWI-interacting RNAs (piRNAs) guide PIWI proteins to suppress transposable elements in animal gonads. Here we demonstrate that in the mouse embryonic male germline, endonucleolytic cleavage (slicing) of a transcript by cytosolic MILI acts as a trigger to initiate its further 5??3? processing into non-overlapping fragments. These fragments accumulate as new piRNAs within the nuclear PIWI protein MIWI2. We identify Exonuclease domain-containing 1 (EXD1) as a partner of the established MIWI2 piRNA biogenesis factor TDRD12. Although EXD1 homodimers are inactive as a nuclease, it functions as an RNA adapter within a PET (PIWI-EXD1-Tdrd12) complex. Loss of Exd1 impacts biogenesis of MIWI2 piRNAs and displays a reduction in sequences generated by MILI slicing. This results in selective depletion of repeat piRNAs that target active retrotransposons like LINE1, which are de-repressed in the mutant. We propose that PIWI slicing and EXD1 promote coordination of nucleo-cytoplasmic silencing via piRNA biogenesis. Immunoprecipitated or total small RNAs were purified and sequenced from P0 mouse testis of Exd1+/- and Exd1 -/- mice. Testes of three males were pooled together and MILI and MIWI2 immunoprecipitation was performed or total small RNAs were purified. Two replicas from different pools were prepared. For Rosa26-pi reporter mouse P0 testes of three males were pooled together and MILI and MIWI2 immunoprecipitation was performed.
Project description:Piwi-interacting RNAs (piRNAs) guide Piwi Argonautes to suppress transposon activity in animal gonads. Known piRNA populations are extremely complex, with millions of individual sequences present in a single organism. Despite this complexity, specific Piwi proteins incorporate piRNAs with distinct nucleotide- and transposon strand-biases (antisense or sense) of unknown origin. Here we examined the contribution of structural domains in Piwi proteins towards defining these biases. We report the first crystal structure of the MID domain from a Piwi Argonaute and use docking experiments to show its ability to specify recognition of 5′ uridine (1U-bias) of piRNAs. Mutational analyses reveal the importance of 5’ end-recognition within the MID domain for piRNA biogenesis in vivo. Finally, domain-swapping experiments uncover an unexpected role for the MID-PIWI module of a Piwi protein in dictating the strand-orientation of its bound piRNAs. Our work identifies structural features that allow distinguishing individual Piwi members during piRNA biogenesis Immunoprecipitated small RNA were purified from Bmn4 cells for preparation of high-throughput sequencing libraries.
Project description:We develop a new ChIpseq method (iChIP) to profile chromatin states of low cell number samples. We use IChIP to profile the chromatin dynamics during hematopoiesis across 16 different cell types which include the principal hematopoietic progenitors 3' RNA-seq for digital gene expression quantitation across multiple cell types.