Project description:We asked whether oocyte number could be amplified through parthenogenesis of mouse oocytes, without requiring creation of a paternal genome and a genetically unique genome. Parthenotes develop to a blastocyst-like stage, and from this parthenogenetic ESCs (pESCs) can be derived with high efficiency. Like ESCs, pESCs maintain unlimited self-renewal and pluripotency, as well as germline competence. Further, we demonstrate that their expression pattern of imprinted maternal genes resembles that observed in oocytes. pESCs can be directed to differentiate into primordial germ cell-like cells (PGCLCs) and form oocytes that produce fertile pups and reconstitute ovarian endocrine functions. The transcriptome and imprinting pattern of PGCLCs differentiated from pESCs more closely approximate those of in vivo produced embryonic PGCs, than PGCLCs produced from ESCs. Parthenogenesis offers a promising route for deriving PGCLCs and amplifying oocytes by faithfully maintaining maternal genes, without fertilization.
Project description:We asked whether oocyte number could be amplified through parthenogenesis of mouse oocytes, without requiring creation of a paternal genome and a genetically unique genome. Parthenotes develop to a blastocyst-like stage, and from this parthenogenetic ESCs (pESCs) can be derived with high efficiency. Like ESCs, pESCs maintain unlimited self-renewal and pluripotency, as well as germline competence. Further, we demonstrate that their expression pattern of imprinted maternal genes resembles that observed in oocytes. pESCs can be directed to differentiate into primordial germ cell-like cells (PGCLCs) and form oocytes that produce fertile pups and reconstitute ovarian endocrine functions. The transcriptome and imprinting pattern of PGCLCs differentiated from pESCs more closely approximate those of in vivo produced embryonic PGCs, than PGCLCs produced from ESCs. Parthenogenesis offers a promising route for deriving PGCLCs and amplifying oocytes by faithfully maintaining maternal genes, without fertilization.
Project description:We asked whether oocyte number could be amplified through parthenogenesis of mouse oocytes, without requiring creation of a paternal genome and a genetically unique genome. Parthenotes develop to a blastocyst-like stage, and from this parthenogenetic ESCs (pESCs) can be derived with high efficiency. Like ESCs, pESCs maintain unlimited self-renewal and pluripotency, as well as germline competence. Further, we demonstrate that their expression pattern of imprinted maternal genes resembles that observed in oocytes. pESCs can be directed to differentiate into primordial germ cell-like cells (PGCLCs) and form oocytes that produce fertile pups and reconstitute ovarian endocrine functions. The transcriptome and imprinting pattern of PGCLCs differentiated from pESCs more closely approximate those of in vivo produced embryonic PGCs, than PGCLCs produced from ESCs. Parthenogenesis offers a promising route for deriving PGCLCs and amplifying oocytes by faithfully maintaining maternal genes, without fertilization.
Project description:Oocytes act as the genetic vector for zygote reprogramming, and stores a large amount of material that is required to regulate embryogenesis. However, to date, there is no report on the dynamic changes of maternal proteins and genes that occur during the early stages of the embryo, particularly studies that use proteomic techniques in buffalos. Here, an integrated single-cell RNA sequencing transcriptomic and quantitative proteomic analysis were employed to systematically explore the dynamic function of maternally-expressed proteins in parthenogenesis model of buffalo.The proteome of the buffalo was quantitatively analyzed during parthenogenesis of mature oocytes and the two-cell stage embryo. Of 1,908 quantified proteins, 123 differed significantly. The transcriptome was analyzed 8 stages (GV, MII, 2-cell,4-cell,8-cell,16-cell,morula,blastocyst)of buffalo using the single-cell RNA sequencing, and a total of 3567 unique genes were identified to be differently expressed between all consecutive stages of pre-implantation development. Bioinformatics studies and validated results indicated that maternal expression of the proteins possibly plays a role in the formation of cellular junctions firstly after parthenogenetic activation and the “maternal-to-zygotic transition” (MZT) process exists during parthenogenesis and occur between the 8-cell to 16-cell stage.
Project description:Mammalian metaphase II (mII) exit and embryogenesis are induced at fertilization by a signal thought to come from the sperm protein, phospholipase C-zeta (PLCZ1). Meiotic progression can also be triggered without sperm, as in parthenogenesis, although the classic mouse in vivo parthenogenetic model, LT/Sv, fails in meiosis I due to an unknown molecular etiology. We here dissect PLCZ1 specificity and function in vivo and address its ability to interfere with maternal meiotic exit. Wild-type mouse Plcz1 expression was restricted to post-pubertal testes, and the brains of both sexes, with region-specifying elements mapping to a 4.1 kb Plcz1 promoter fragment. When broad ectopic PLCZ1 expression was forced in independent transgenic lines, they initially appeared healthy. Their oocytes underwent unperturbed meiotic maturation to mII but subsequently exhibited autonomous intracellular free calcium oscillations, second polar body extrusion, pronucleus formation and parthenogenetic development. Transfer of transgenic cumulus cell nuclei into wild-type oocytes induced activation and development, demonstrating a direct effect of PLCZ1 analogous to fertilization. Whilst Plcz1 transgenic males remained largely asymptomatic, females developed abdominal swellings caused by benign ovarian teratomas that were under-represented for paternally- and placentally-expressed transcripts. Plcz1 was not over-expressed in the ovaries of LT/Sv or in human germline ovarian tumours. The narrow spectrum of PLCZ1 activity indicates that it is modulated by tissue-restricted accessory factors. This work characterizes a novel model in which parthenogenesis and tumourigenesis follow full meiotic maturation and are linked to fertilization by PLCZ1. Keywords: miRNA profiling; expression profiling of mouse miRNAs_SampleB Fourteen samples were analyzed for the study.
Project description:Background:Maternal mRNAs that accumulate in the oocyte during oogenesis play important roles during initial stages of embryonic development, before activation of the embryonic genome. Parthenogenesis of mammalian is a critical research modle for the function analysis of maternal genomics. Results:Here we report comprehensive maternal transcriptome dynamics of single matured oocytes and pre-implantation embryos of buffalo parthenogenesis.Notably, more than half of the estimated 28659 bovine genes,15331 involved in more than 280 pathways, is expressed in oocytes and early embryos of parthenogenesis .The total numbers of genes expressed across stages are from 908 genes (morula/16cells)to 2603 genes(blastocyst/morula), and the nature of the expressed genes is also greatly different. A total of 3567 unique genes were identified to be differentially expressed between all consecutive stages of development(FPKM>0),of which the biggest expressed change was detected between the 8-and 16-cell stages, which demonstrated that parthenogenetic activation of embryonic development exist an embryonic genome activation process which is the same as the normal fertilization of embryos,also occurs between 8cells-16cells, consistent with the time of the development of the normal fertilized embryonic development,which suggesting that parthenogenetic embryonic development and normal fertilization embryo development may have a similar genome activation transcription regulation process.Besides,2726 genes were identified as only expressed/highly enriched in particular stages of development, suggesting their stage-specific roles in maternal genome during embryogenesis.Using weighted gene co-expression network analysis, we found 11 stage-specific modules of co-expressed genes that can be used to represent the corresponding stage of development. Furthermore, we identified 1530 hub genes of the maternally expressed gene networks. Methods:Maternal mRNA profiles of pre-implantation development in buffalo parthenogenesis,using single-cell RNA sequencing in IlluminaHiSeq platform. Sequencing adapters were trimmed using Cutadapt (https://code.google.com/p/cutadapt/) and the filtered reads were mapped to the reference genome sequence (ftp://ftp.ncbi.nlm.nih.gov/genomes/all/GCA/000/471/725/GCA_000471725.1_UMD_CASPUR_WB_2.0/)assembly using Tophat2 followed by Cufflinks.qRT–PCR validation was performed using SYBR Green assays. Conclusions:This study provides a comprehensive examination of maternally expressed gene activities in buffalo oocytes and pre-implantation embryos of parthenogenesis for the first time,and find the special “EGA”between 8cells-16cells for parthenogenetic embry,and the study screen a number of specific stages hub gene with potentially important function.