Project description:The first site exhibiting hematopoietic activity in mammalian development is the yolk sac blood island, which originates from the hemangioblast. Here we performed differentiation assays, as well as genome-wide molecular and functional studies in BL-CFCs to gain insight into the function of the essential Ldb1 factor in early primitive hematopoietic development. We show that the previously reported lack of yolk sac hematopoiesis and vascular development in Ldb1-/- mouse result from a decreased number of hemangioblasts and a block in their ability to differentiate into erythroid and endothelial progenitor cells. Transcriptome analysis and correlation with the genome wide binding pattern of Ldb1 in hemangioblasts revealed a number of direct target genes and pathways misregulated in the absence of Ldb1. The regulation of essential developmental factors by Ldb1 defines it as an upstream transcriptional regulator of hematopoietic/endothelial development. We show the complex interplay that exists between transcription factors and signaling pathways during the very early stages of hematopoietic/endothelial development and the specific signalling occurring in hemangioblasts in contrast to more advanced hematopoietic developmental stages. Finally, by revealing novel genes and pathways, not previously associated with early development, our study provides novel candidate targets to manipulate the differentiation of hematopoietic and/or endothelial cells. Examination of endogenous Ldb1 genome-wide binding sites comparsion between ChIP and Control on Flk1+ BL-CFCs RNA was isolated from Ldb1+/+ and Ldb1-/- Flk1+ cells with the QIAGEN RNeasy Mini Kit and integrity was checked on the Agilent 2100 Bioanalyzer. RNA sequencing was performed on Illumina HiSeq 2000 platform according to the manufacturer instructions.
Project description:Snai1 is a master factor of epithelial to mesenchymal transitioin (EMT), however, its role in embryonic stem cell (ESC) differentiation and lineage commitment remains undefined. We used microarrays to compare the global programme of gene expression between control and Snai1 knockout Flk1+ and Flk1- cells sorted from 4 day EBs. Control and Snai1 knockout ESCs were cultured as embryoid bodies in spotaneous differentiation media, 4 days EBs were dissociated and sorted by anti-Flk1 antibody to separated Flk1+ and Flk1- cells, total RNA were collected for Affymetrix microarrays
Project description:ES cells differentiated in the presence of the Wnt inhibitor DKK1 fail to express the transcription factor Snail and undergo EMT or mesoderm differentiation. We generated an ES cell line, A2.snail, that induced Snail expression upon addition of doxycycline addition. Microarrays were used to gain a global picture of Flk1- and Flk1+ cells generated one day after Snail was expressed during Wnt inhibition. A2.snail ES cells, which express Snail upon addition of doxycycline, were differentiated as embryoid bodies in differentiation media and DKK1. Snail-induced cultures uniquely develop a select population of Flk1+ cells. Total RNA was harvested from sorted control (no doxycycline) Flk1- cells and sorted Snail-induced (doxycycline at day 2) Flk1- and Flk1+ cells at day 3 of differentiation.
Project description:The first site exhibiting hematopoietic activity in mammalian development is the yolk sac blood island, which originates from the hemangioblast. Here we performed differentiation assays, as well as genome-wide molecular and functional studies in BL-CFCs to gain insight into the function of the essential Ldb1 factor in early primitive hematopoietic development. We show that the previously reported lack of yolk sac hematopoiesis and vascular development in Ldb1-/- mouse result from a decreased number of hemangioblasts and a block in their ability to differentiate into erythroid and endothelial progenitor cells. Transcriptome analysis and correlation with the genome wide binding pattern of Ldb1 in hemangioblasts revealed a number of direct target genes and pathways misregulated in the absence of Ldb1. The regulation of essential developmental factors by Ldb1 defines it as an upstream transcriptional regulator of hematopoietic/endothelial development. We show the complex interplay that exists between transcription factors and signaling pathways during the very early stages of hematopoietic/endothelial development and the specific signalling occurring in hemangioblasts in contrast to more advanced hematopoietic developmental stages. Finally, by revealing novel genes and pathways, not previously associated with early development, our study provides novel candidate targets to manipulate the differentiation of hematopoietic and/or endothelial cells. We used microarrays to detail the global programme of gene expression underlying the Ldb1+/+ and Ldb1-/- in Flk1+ cells. RNA was isolated from Ldb1+/+ and Ldb1-/- Flk1+ cells with the QIAGEN RNeasy Mini Kit and integrity was checked on the Agilent 2100 Bioanalyzer. RNA was converted to biotin-labelled cRNA, hybridised on the Mouse Genome 430 2.0 Array and analyzed with the Affymetrix GeneChip® Scanner 3000 according to the manufacturer protocol.
Project description:We used high throughput miRNA sequencing to investigate differences between two mESC lines (D3 and B8 ESCs). Undifferentiated ESCs, cells differentiating in embryoid bodies (day 7), and also cells from embryoid bodies outgrowth (day 21) were analyzed.
Project description:mESCs were in vitro differentiated into embryoid bodies under suspension cultured condition and was collected at day 9 of differentiation. Polyadenylated mRNAs of mESCs and EBs were isolated and used to build the sequencing library.
Project description:The first site exhibiting hematopoietic activity in mammalian development is the yolk sac blood island, which originates from the hemangioblast. Here we performed differentiation assays, as well as genome-wide molecular and functional studies in BL-CFCs to gain insight into the function of the essential Ldb1 factor in early primitive hematopoietic development. We show that the previously reported lack of yolk sac hematopoiesis and vascular development in Ldb1-/- mouse result from a decreased number of hemangioblasts and a block in their ability to differentiate into erythroid and endothelial progenitor cells. Transcriptome analysis and correlation with the genome wide binding pattern of Ldb1 in hemangioblasts revealed a number of direct target genes and pathways misregulated in the absence of Ldb1. The regulation of essential developmental factors by Ldb1 defines it as an upstream transcriptional regulator of hematopoietic/endothelial development. We show the complex interplay that exists between transcription factors and signaling pathways during the very early stages of hematopoietic/endothelial development and the specific signalling occurring in hemangioblasts in contrast to more advanced hematopoietic developmental stages. Finally, by revealing novel genes and pathways, not previously associated with early development, our study provides novel candidate targets to manipulate the differentiation of hematopoietic and/or endothelial cells. We used microarrays to detail the global programme of gene expression underlying the Ldb1+/+ and Ldb1-/- in Flk1+ cells.