Cultured pluripotent stem cells are a cornerstone of regenerative medicine due to their ability to give rise to all cell types of the body. While pluripotent stem cells can be propagated indefinitely in vitro, pluripotency is paradoxically a very transient state in vivo, lasting 2-3 days around the time of blastocyst implantation. The exception to this rule is embryonic diapause, a reversible state of suspended development triggered by unfavorable conditions. Diapause is a strategy widely employed across the animal kingdom, including in mammals, but its regulation remains poorly understood. Here we report that inhibition of mechanistic target of rapamycin (mTor), a major nutrient sensor and promoter of growth, induces reversible pausing of mouse blastocyst development and allows their prolonged culture ex vivo. Paused blastocysts remain pluripotent and competent to give rise to embryonic stem (ES) cells and mice. We show that both natural diapause blastocysts in vivo and paused blastocysts ex vivo display pronounced reductions in mTor activity, translation and transcription. In addition, pausing can be induced directly in cultured ES cells and sustained for weeks in the absence of cell death or deviations from cell cycle distributions. We show that paused ES cells remain pluripotent, display a remarkable global suppression of transcription, and maintain a gene expression signature of diapaused blastocysts. These results allow for the first time the sustained suspension of development of a mammalian embryo in the laboratory, and shed light on the regulation of diapause and the origins of ES cells. Our findings have important implications in the fields of assisted reproduction, regenerative medicine, cancer, metabolic disorders and aging. Overall design: Examination of RNA expression profiles of embryonic stem cells in serum, 2i and paused states by RNA-seq
Inhibition of mTOR induces a paused pluripotent state.
Specimen part, Cell line, Treatment, Subject
View SamplesTransposable elements make up nearly half of mammalian genomes, yet are generally described as 'junk DNA' or genome parasites. The LINE1 retrotransposon is the most abundant class and is thought to be deleterious for cells, but it is paradoxically expressed at high levels during early development. Here, we report that LINE1 plays essential roles in mouse embryonic stem (ES) cells and pre-implantation embryos. In ES cells, LINE1 acts as a nuclear RNA scaffold that recruits Nucleolin and Kap1/Trim28 to repress Dux, the master activator of a gene expression program specific to the 2-cell stage. In parallel, LINE1 RNA mediates binding of Nucleolin and Kap1 to rDNA, thereby promoting rRNA synthesis and ES cell self-renewal. In embryos, LINE1 RNA is required for silencing of Dux, proper synthesis of rRNA and exit from the 2-cell stage. These results reveal an essential partnership between nuclear LINE1 RNA and chromatin factors in the regulation of transcription, developmental potency and ES cell self-renewal. Overall design: 3 replicates each of E14 ES cells two days after nucleofection with Lissaminated ASOs - RC (control) or LINE1, purified according to Lissamine+ using flow cytometry then lysed for RNA extraction and library generation (6 samples total)
A LINE1-Nucleolin Partnership Regulates Early Development and ESC Identity.
Specimen part, Cell line, Subject
View SamplesMorphogenesis of the mammary gland relies on the precise developmental control of morphological elements including TEBs, ducts and lobules. In the peripubertal mammary gland, rising levels of ovarian hormones control this development through a tightly controlled genetic program where specific sets of genes are up-regulated.
In utero and lactational exposure to vinclozolin and genistein induces genomic changes in the rat mammary gland.
Specimen part, Treatment
View SamplesVascular endothelial growth factor is a multifunctional cytokine playing important roles in angiogenesis, tumor progression and metastasis. Alternative splicing results in the production of several different isoforms of VEGF. We have previously generated human breast cancer cells overexpressing VEGF165 or VEGF189 isoforms (referred to as the V165 and V189 clones, respectively) and showed that VEGF189-transfected cells were less tumorigenic. In this study, we used bioluminescence imaging to analyze the metastasis capacity of breast cancer cell lines (MDA-MB-321) overexpressing VEGF isoforms in nude mice. V165, V189 and control cV clones were transfected with a luciferase plasmid to generate bioluminescent clones (the V165-B, V189-B and cV clones, respectively). These clones were then injected into the left heart ventricle of nude mice.
MDA-MB-231 breast cancer cells overexpressing single VEGF isoforms display distinct colonisation characteristics.
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View SamplesConditional deletion of Lhx2, and to a lesser extent, Emx2 in olfactory neurons alters odorant receptor expression frequency.
Lhx2 Determines Odorant Receptor Expression Frequency in Mature Olfactory Sensory Neurons.
Specimen part
View SamplesConditional deletion of Lhx2, and to a lesser extent, Emx2 in olfactory neurons alters odorant receptor expression frequency.
Lhx2 Determines Odorant Receptor Expression Frequency in Mature Olfactory Sensory Neurons.
Specimen part
View SamplesConditional deletion of Lhx2, and to a lesser extent, Emx2 in olfactory neurons alters odorant receptor expression frequency.
Lhx2 Determines Odorant Receptor Expression Frequency in Mature Olfactory Sensory Neurons.
Specimen part
View SamplesConditional deletion of Lhx2, and to a lesser extent, Emx2 in olfactory neurons alters odorant receptor expression frequency. This series describes 1 of the 5 array experiments.
Lhx2 Determines Odorant Receptor Expression Frequency in Mature Olfactory Sensory Neurons.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Lhx2 Determines Odorant Receptor Expression Frequency in Mature Olfactory Sensory Neurons.
Specimen part
View SamplesConditional deletion of Lhx2, and to a lesser extent, Emx2 in olfactory neurons alters odorant receptor expression frequency.
Lhx2 Determines Odorant Receptor Expression Frequency in Mature Olfactory Sensory Neurons.
Specimen part
View Samples