Project description:Oocyte defects lie at the heart of some forms of infertility and could potentially be addressed therapeutically by alternative routes for oocyte formation. Here, we describe the generation of functional human oocytes following nuclear transfer of first polar body (PB1) genomes from metaphase II (MII) oocytes into enucleated donor MII cytoplasm (PBNT). The reconstructed oocytes supported the formation of de novo meiotic spindles and, after fertilization with sperm, meiosis completion and formation of normal diploid zygotes. While PBNT zygotes developed to blastocysts less frequently (42%) than controls (75%), genome-wide genetic, epigenetic, and transcriptional analyses of PBNT and control ESCs indicated comparable numbers of structural variations and markedly similar DNA methylation and transcriptome profiles. We conclude that rescue of PB1 genetic material via introduction into donor cytoplasm may offer a source of oocytes for infertility treatment or mitochondrial replacement therapy for mtDNA disease.
Project description:Oocyte defects lie at the heart of some forms of infertility and could potentially be addressed therapeutically by alternative routes for oocyte formation. Here, we describe the generation of functional human oocytes following nuclear transfer of first polar body (PB1) genomes from metaphase II (MII) oocytes into enucleated donor MII cytoplasm (PBNT). The reconstructed oocytes supported the formation of de novo meiotic spindles and, after fertilization with sperm, meiosis completion and formation of normal diploid zygotes. While PBNT zygotes developed to blastocysts less frequently (42%) than controls (75%), genome-wide genetic, epigenetic, and transcriptional analyses of PBNT and control ESCs indicated comparable numbers of structural variations and markedly similar DNA methylation and transcriptome profiles. We conclude that rescue of PB1 genetic material via introduction into donor cytoplasm may offer a source of oocytes for infertility treatment or mitochondrial replacement therapy for mtDNA disease.
Project description:Clinicians need additional metrics for predicting quality of human oocytes for IVF procedures. Human polar bodies reflect the oocyte transcript profile. Quantitation of polar body mRNAs could allow for both oocyte ranking and embryo preferences in IVF applications. The transcriptome of a polar body has never been reported, in any organism. Eight total samples. There are 2 biological replicates of the following four conditions: pooled oocytes and their sister polar bodies and a single oocyte and its sister polar body.
Project description:Clinicians need additional metrics for predicting quality of human oocytes for IVF procedures. Human polar bodies reflect the oocyte transcript profile. Quantitation of polar body mRNAs could allow for both oocyte ranking and embryo preferences in IVF applications. The transcriptome of a polar body has never been reported, in any organism.
Project description:Here we report the derivation of human PBTESCs from polar body transfer resconstructed embryos. We used RNA-seq to compare the gene expression levels among human parthenogenetic haploid ESCs (hPGES)、normal human ESCs (H9) and human forskin fibroblasts and identified that these cells express conventional ESCs pluripotent markers and most maternally imprinted genes were down-regulated.
Project description:The stem cell lines were generated according to the principle described in Noggle et al., Nature 2011, Oct 5;478(7367):70-5. doi: 10.1038/nature10397. Title: Human oocytes reprogram somatic cells to a pluripotent state. Abstract: The exchange of the oocyte's genome with the genome of a somatic cell, followed by the derivation of pluripotent stem cells, could enable the generation of specific cells affected in degenerative human diseases. Such cells, carrying the patient's genome, might be useful for cell replacement. Here we report that the development of human oocytes after genome exchange arrests at late cleavage stages in association with transcriptional abnormalities. In contrast, if the oocyte genome is not removed and the somatic cell genome is merely added, the resultant triploid cells develop to the blastocyst stage. Stem cell lines derived from these blastocysts differentiate into cell types of all three germ layers, and a pluripotent gene expression program is established on the genome derived from the somatic cell. This result demonstrates the feasibility of reprogramming human cells using oocytes and identifies removal of the oocyte genome as the primary cause of developmental failure after genome exchange. The major difference to Noggle et al. are that these new stem cell lines are tetraploid rather than diploid. The main technical difference is the addition of cytochalasinB during artificial activation, preventing extrusion of the second polar body, thereby resulting in the retention of a diploid oocyte genome, rather than a haploid one. Adult somatic cells were transferred into non-enucleated oocytes and then activated in the presence of cytochalasinB. Addition of cytochalasinB inhibits extrusion of the second polar body, resulting in tetraploid eggs. The efficiency of development to the blastoycst stage is described in: Yamada et al., 2014, Human oocytes reprogram adult somatic nuclei of a type 1 diabetic to diploid pluripotent stem cells, Nature. 2014 Jun 26;510(7506):533-6. doi: 10.1038/nature13287. Blastocysts developing from these were used for the derivation or pluripotent stem cell lines. Gene expression analysis was performed to demonstrate transcriptional reprogramming. These cell lines contain both somatic and oocyte genomes.