Project description:Although polar body transfer (PBT) has the potential to prevent the transmission of inherited mitochondrial DNA (mtDNA) diseases, the PBT technique is still at an early stage, as no human data are publicly available for PBT. Here, we investigated the comparative values of first and second PBT (PB1T, PB2T), spindle-chromosome and pronuclear transfer (ST, PNT), modified ST and PNT (mST and mPNT) to explore the efficiency and safety of these approaches. A comparative analysis confirmed that PB1T, mST, PB2T and mPNT could be used to donate mtDNA without resulting in significant heteroplasmy or alterations in the methylation profile and gene expression. Importantly, PB1T produced reconstructed embryos and embryonic stem cells (ESCs) in every generation with undetectable donor mtDNA. However, donor mtDNA seems to have a tendency to be amplified in generations of mPNT-ESCs with up to 3% heteroplasmy. These results suggest that PB1T holds great potential in eliminating mtDNA variants.
Project description:Although polar body transfer (PBT) has the potential to prevent the transmission of inherited mitochondrial DNA (mtDNA) diseases, the PBT technique is still at an early stage, as no human data are publicly available for PBT. Here, we investigated the comparative values of first and second PBT (PB1T, PB2T), spindle-chromosome and pronuclear transfer (ST, PNT), modified ST and PNT (mST and mPNT) to explore the efficiency and safety of these approaches. A comparative analysis confirmed that PB1T, mST, PB2T and mPNT could be used to donate mtDNA without resulting in significant heteroplasmy or alterations in the methylation profile and gene expression. Importantly, PB1T produced reconstructed embryos and embryonic stem cells (ESCs) in every generation with undetectable donor mtDNA. However, donor mtDNA seems to have a tendency to be amplified in generations of mPNT-ESCs with up to 3% heteroplasmy. These results suggest that PB1T holds great potential in eliminating mtDNA variants.
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:Here we report the derivation of human ESCs from the polar body thansfer reconstructed embryos. We choose three cell lines from all the cell lines and compare the DNA methylation state. We use human methylation chip to compare genomic DNA methylation level among three PB1 transfer human ES cell lines and three PB2 transfer human ES cell lines.
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:Somatic cell nuclear transfer (SCNT) successfully clones cynomolgus monkeys, but the efficiency remains low due to a limited understanding of the reprogramming mechanism. Notably, no rhesus monkey has been cloned through SCNT so far. Our study conducts a comparative analysis of multi-omics datasets, comparing embryos resulting from intracytoplasmic sperm injection (ICSI) with those from SCNT. Our findings reveal a widespread decrease in DNA methylation and the loss of imprinting in maternally imprinted genes within SCNT monkey blastocysts. This loss of imprinting persists in SCNT embryos cultured in-vitro until E17 and in full-term SCNT placentas. Additionally, histological examination of SCNT placentas shows noticeable hyperplasia and calcification. To address these defects, we develop a trophoblast replacement method, ultimately leading to the successful cloning of a healthy male rhesus monkey. These discoveries provide valuable insights into the reprogramming mechanism of monkey SCNT and introduce a promising strategy for primate cloning.
Project description:Mitochondria are found in all eukaryotic cells and contain their own genome (mitochondrial DNA or mtDNA). Unlike the nuclear genome, which is derived from both the egg and sperm at fertilization, the mtDNA in the embryo is derived almost exclusively from the egg; that is, it is of maternal origin. Mutations in mtDNA contribute to a diverse range of currently incurable human diseases and disorders. To establish preclinical models for new therapeutic approaches, we demonstrate here that the mitochondrial genome can be efficiently replaced in mature non-human primate oocytes (Macaca mulatta) by spindle-chromosomal complex transfer from one egg to an enucleated, mitochondrial-replete egg. The reconstructed oocytes with the mitochondrial replacement were capable of supporting normal fertilization, embryo development and produced healthy offspring. Genetic analysis confirmed that nuclear DNA in the three infants born so far originated from the spindle donors whereas mtDNA came from the cytoplast donors. No contribution of spindle donor mtDNA was detected in offspring. Spindle replacement is shown here as an efficient protocol replacing the full complement of mitochondria in newly generated embryonic stem cell lines. This approach may offer a reproductive option to prevent mtDNA disease transmission in affected families.
Project description:Highly efficient systems are needed to link perception with action in the context of the highly complex environments in which primates move and interact. Another important component is, nonetheless, needed for action: selection. When one piece of fruit from a branch is being chosen by a monkey, many other pieces are within reach and visible: do the perceptual features of the objects surrounding a target determine interference effects? In humans, reaching to grasp a desired object appears to integrate the motor features of the objects which might become potential targets - a process which seems to be driven by inhibitory attention mechanisms. Here we show that non-human primates use similar mechanisms when carrying out goal-directed actions. The data indicate that the volumetric features of distractors are internally represented, implying that the basic cognitive operations allowing for action selection have deep evolutionary roots.