• The ability to study human post-implantation development remains limited owing to ethical and technical challenges associated with intrauterine development after implantation 1 . (nature.com)
  • Embryo-like models with spatially organized morphogenesis and structure of all defining embryonic and extra-embryonic tissues of the post-implantation human conceptus (that is, the embryonic disc, the bilaminar disc, the yolk sac, the chorionic sac and the surrounding trophoblast layer) remain lacking 1 , 2 . (nature.com)
  • Such human fully integrated and complete SEMs recapitulate the organization of nearly all known lineages and compartments of post-implantation human embryos, including the epiblast, the hypoblast, the extra-embryonic mesoderm and the trophoblast layer surrounding the latter compartments. (nature.com)
  • These human complete SEMs demonstrated developmental growth dynamics that resemble key hallmarks of post-implantation stage embryogenesis up to 13-14 days after fertilization (Carnegie stage 6a). (nature.com)
  • This SEM platform will probably enable the experimental investigation of previously inaccessible windows of human early post implantation up to peri-gastrulation development. (nature.com)
  • and (3) evidence of developmental dynamism relating to ability to progress, in a structurally organized manner, through morphologically characterized developmental milestones of the early post-implantation human embryo following initial aggregate formation 3 . (nature.com)
  • Here, we describe a protocol to culture human embryos from pre- to post-implantation stages in vitro , in the absence of maternal tissues. (researchsquare.com)
  • This protocol describes in detail how human cleavage-stage or blastocyst-stage embryos are thawed and cultured through pre- to-post-implantation stages in vitro and how they can be analysed by immunofluorescence. (researchsquare.com)
  • Although it is possible to culture structures derived from human blastocysts ex vivo, these cultures do not recapitulate the events and structural organization of the in vivo embryos 6 ( Supplementary Information ). (nature.com)
  • The development of the human embryo beyond implantation has been poorly characterised, because in vivo experiments are unfeasible and there is no appropriate in vitro culture system. (researchsquare.com)
  • Despite its basic and clinical importance, the morphogenesis of the human embryo at the time of implantation remains largely unknown, because in vivo experiments are not feasible and a system to culture human embryos beyond day 7 in vitro 1 has not been developed. (researchsquare.com)
  • By comparing embryos developing in vitro with the Carnegie series of human embryos developing in vivo 6 , we have uncovered the major morphogenetic events of human implantation morphogenesis, including: segregation of embryonic and extra-embryonic lineages, formation of the pro-amniotic and yolk sac cavities, and generation of a bi-laminar structure. (researchsquare.com)
  • This study was conducted to evaluate in vivo and in vitro development of in vitro-matured equine oocytes fertilized by intracytoplasmic sperm injection. (bioone.org)
  • Mouse naive embryonic stem cells have recently been shown to give rise to embryonic and extra-embryonic stem cells capable of self-assembling into post-gastrulation structured stem-cell-based embryo models with spatially organized morphogenesis (called SEMs) 3 . (nature.com)
  • We anticipate that future studies using these two in vitro culture systems will help us understand how embryonic and extra-embryonic tissues cooperate to generate the basic human body plan. (researchsquare.com)
  • The developing embryo, from which pluripotent stem cells originate, undergoes a series of dynamic metabolic transitions synchronized to its molecular development. (conditionmed.org)
  • In mouse, a unidirectional demethylation process from the zygote stage to blastocyst stage is observed using either reduced representation bisulfite sequencing (RRBS) or single-base resolution whole-genome bisulfite sequencing (WGBS) method. (nature.com)
  • We therefore decided to investigate comprehensively the global and high-resolution DNA methylation dynamics during early development of a non-human primate (rhesus monkey, Macaca mulatta ). (nature.com)
  • Toxicological consequences of Aroclor 1254 ingestion by female Rhesus ( Macaca mulatta ) monkeys. (cdc.gov)
  • 1999. Toxicological consequences of feeding PCB congeners to infant Rhesus ( Macaca mulatta ) and Cynomolgus ( Macaca fascicularis ) monkeys. (cdc.gov)
  • On the 7th day of human embryo development, the free-floating blastocyst must implant into the uterus to allow the organisation of the embryonic (epiblast) and extra-embryonic (hypoblast and trophoblast) tissues, and the formation of the future body plan. (researchsquare.com)
  • The National Institutes of Health defines a human embryo as "the developing organism from the time of fertilization until the end of the eighth week of gestation. (archstl.org)
  • Gamete outcome Shortly after fertilization a zygote develops into a multicellular embryo that in turn develops into a larger organism. (wikipedia.org)
  • Usage of melatonin during in vitro fertilization (IVF) procedures has been found to improve oocyte quality, survival, and fecundity. (jrhm.org)
  • In 1-cell and 2-cell embryos Dnmt1s is derived from the oocyte, whereas from the 2-cell stage onward the embryo starts to synthesize its own Dnmt1s 8 . (nature.com)
  • Most importantly, our DNA methyltransferase loss-of-function analysis indicates that DNA methylation influences early monkey embryogenesis. (nature.com)
  • However, robust and large-scale genome-wide reprogramming of DNA methylome occurs during two critical developmental processes: (1) development of primordial germ cells and (2) pre-implantation embryogenesis. (nature.com)
  • Although the genome-wide DNA demethylation is believed to be a hallmark of mammalian embryogenesis, previous study also indicated that the somatic form of dnmt1 ( dnmt1s ) is actually expressed at each stage of pre-implantation embryos and plays a role in the maintenance of DNA imprinting 8 . (nature.com)
  • These results strongly suggest the possibility of DNA remethylation during pre-implantation embryogenesis. (nature.com)
  • Monkeys have served as one of the most valuable models for understanding DNA methylation dynamics during early embryogenesis in human due to their similarities in genetics and early embryonic development 17 , 18 . (nature.com)
  • Remarkably, all these events happen in vitro in the absence of maternal tissues, indicating that human embryos have a previously underappreciated self-organizing potential. (researchsquare.com)
  • The Catholic Church has always held that stem-cell research and therapies are morally acceptable, as long as they don't involve the creation and destruction of human embryos. (archstl.org)
  • It is only through understanding embryonic metabolism and development that we can derive and maintain different in vitro stem cell states for disease modeling and therapies. (conditionmed.org)
  • Morbidly adherent placenta (MAP) is the general clinical term used to describe the different forms of abnormal placental implantation ( Accreta , Increta and Percreta ). (edu.au)
  • Furthermore, due to ethical and legal concerns, very limited techniques can be applied to human embryos to validate some of significant conclusions drawn from descriptive studies regarding human embryonic development. (nature.com)
  • Implantation of the human embryo leads to a number of changes in organization that are essential for gastrulation and future development 1 . (nature.com)
  • This protocol represents a unique opportunity to study the cellular and molecular mechanisms of human embryo development beyond implantation. (researchsquare.com)
  • However, whether similar events happen in human embryos remains an open question. (researchsquare.com)
  • Here, we have established a system that allows human embryos to develop in vitro through implantation stages, using a method that we recently developed to culture mouse embryos through implantation 5 as a starting point. (researchsquare.com)
  • We anticipate that the methods presented here will be instrumental to understanding the cellular and molecular mechanisms that shape the future human body at implantation. (researchsquare.com)
  • That's why Father Pacholczyk, director of education at the National Catholic Bioethics Center in Philadelphia, said that the efforts to help people understand the immorality of embryo reserch, including human cloning, must focus on humanizing the issue and appreciating our own embryonic origins, not just on the desired results of embryonic or other types of stem-cell research. (archstl.org)
  • Unlike in rodents, X chromosome inactivation is not observed during monkey pre-implantation development. (nature.com)
  • Studies on the development of monkey embryos have provided some understanding of the major morphogenetic events that take place at the time of implantation 2-4 . (researchsquare.com)
  • An embryo in its first days of development is no bigger than a period at the end of a sentence, Father Pacholczyk often points out. (archstl.org)
  • 1991. Effects of polychlorinated biphenyls with Ah receptor affinity on lymphoid development in the thymus and the bursa of Fabricius on chick embryos in ovo and in mouse thymus anlagen in vitro . (cdc.gov)
  • Here, we consider the metabolism of the early embryo through development, and look at the nutrient milieu within the developing stem cell niche. (conditionmed.org)
  • In the mouse, a transporting epithelium is established around the 8-16-cell stage through a process known as compaction where cell definition is lost and the outer cells of the embryo form tight junctions, giving rise to the blastocyst. (conditionmed.org)
  • Father Pacholczyk, who is teaching a course on bioethics and life issues at Kenrick-Glennon Seminary this semester, said it is very easy to depersonalize humans when they are in the earliest stages of life. (archstl.org)
  • Other recent studies verified the presence of PAPP-A mRNA in granulosa cells of humans, monkeys, cattle, mice, and pigs. (bioone.org)
  • The mammalian ovary has all the molecular machinery required for the biosynthesis of melatonin and interestingly concentration of melatonin in the follicular fluid of pre-ovulatory follicles is much higher than circulatory melatonin even in humans. (jrhm.org)
  • In placental mammals this process of gestation occurs inside the reproductive system of the mother of the embryo. (wikipedia.org)
  • Immunity that targets gamete outcome induces abortion of an embryo while it is within its mother's reproductive system. (wikipedia.org)
  • Exposure to stress strongly influences hypothalamic-pituitary-adrenal axis and elevated glucocorticoid levels suppress various ovarian functions including implantation thereby pregnancy. (jrhm.org)
  • In the Eppin trial that attained 100% infertility, a small sample size (only 9 monkeys) was used, and even among this small sample 2 monkeys were dropped from the study because they failed to produce sufficiently high antibody titers. (wikipedia.org)
  • Here we report genome-wide composition, patterning, and stage-specific dynamics of DNA methylation in pre-implantation rhesus monkey embryos as well as male and female gametes studied using an optimized tagmentation-based whole-genome bisulfite sequencing method. (nature.com)
  • In vitro studies based on MCF-7 cell proliferation and induction of vitellogenin in primary culture of rainbow trout hepatocytes. (cdc.gov)
  • When people argue that the embryo is too small to consider its humanity, Father Pacholczyk, a neuroscientist and theologian, uses an analogy of a bomber plane flying high in the sky. (archstl.org)
  • For instance, in the second LDH-C4 primate trial that had negative results, all of the immunized macaque monkeys developed high antibody titers against LDH-C4 in serum, but antibodies against LDH-C4 were not found in the monkeys' vaginal fluids. (wikipedia.org)
  • Mares were killed 7.5-8.5 days after transfer and the uterus and oviducts flushed for embryo recovery. (bioone.org)
  • I often say to people the day is coming when you're going to open the New York Times, and above the fold, it's going to say, 'Embryos cure Parkinson's,' or 'Embryos cure diabetes,'" he said. (archstl.org)
  • Millions of people suffer from end-stage refractory diseases. (frontiersin.org)