"Researchers in Singapore have discovered that eggs from old mice can be rejuvenated by placing them in the ovaries of young mice. This process significantly increases the chances of healthy offspring. Scientists transplanted oocytes from old mice to young ones and vice versa. Eggs in young ovaries showed improved quality, including fewer chromosomal abnormalities and better mitochondrial function. After fertilization and embryo transfer into surrogate mice, the “rejuvenated” eggs had a significantly higher chance of developing healthy offspring. They attribute this to a higher density of nutritional connections between oocytes and follicles in young mice. The research could help develop treatments for female infertility and improve egg quality in older women, although further research is needed for application to humans."
https://www.nature.com/articles/d41586-024-02872-x
On average, 18 patients die each day while waiting for a transplant in Europe. Every 10 min, someone is added to the national transplant waiting list. At present, more than 14,500 people are on active organ waiting list.
https://www.eurotransplant.org/cms/
" Today, Massachusetts General Hospital (MGH), a founding member of the Mass General Brigham health care system, announced the world’s first successful transplant of a genetically-edited pig (porcine) kidney into a 62-year-old man living with end-stage kidney disease (ESKD). Surgeons from the Mass General Transplant Center conducted the four-hour-long surgery on Saturday, March 16. The procedure marks a major milestone in the quest to provide more readily available organs to patients. Mass General Brigham is an internationally recognized leader in transplantation services, providing advanced care for a wide spectrum of organ and tissue transplants throughout its renowned academic medical system.
...
The patient, Mr. Richard ‘Rick’ Slayman of Weymouth, Mass., is recovering well at MGH and is expected to be discharged soon."
"'Brave New World' just got more real with the first mammal ever born from an unfertilized egg"
"Parthenogenesis does not happen naturally in mammals, and previous attempts ran into DNA glitches. Because mammalian conception needs genes that can only come from a male parent, the research team solved that by editing certain female genes with CRISPR until they were the same as if they had come from a male. They repeated the process with several eggs. These were then implanted into the female’s uterus and allowed to grow, and they went from embryonic to fetal stages to actual, living offspring, one of which was eventually able to produce its own offspring."
https://www.syfy.com/syfy-wire/parthenogenesis-has-been-achieved-in-mammals-for-the-first-time
"In mammals, parthenogenesis is limited because of problems arising from genomic imprinting. Here, we report live mammalian offspring derived from single unfertilized eggs. This was achieved by the targeted DNA methylation rewriting of seven imprinting control regions. By designing guide RNAs with protospacer adjacent motif (PAM) sequences matching one allele but not the other, dCas9-Dnmt3a or dCpf1-Tet1 enables targeted DNA methylation editing in an allele-specific manner. The success of parthenogenesis in mammals opens many opportunities in agriculture, research, and medicine."
https://www.pnas.org/doi/full/10.1073/pnas.2115248119
Cloned Przewalski Horses are ‘Resurrected Stallions’ That Could Help Species Thrive, Scientists Say
"Przewalski's horses cloned from a stallion that died in 1998 could help reintroduce much needed diversity to the species that was once declared extinct in the wild."
https://www.viagenpets.com/
"Mammalian in vitro gametogenesis"
https://www.science.org/doi/10.1126/science.aaz6830
Research on in vitro gametogenesis (IVG) aims to reconstitute germ cell development, oogenesis and spermatogenesis, in culture. Saitou and Hayashi review some of the recent developments in mammalian IVG. Advances in methods and culture conditions in mice to generate mature oocytes and spermatocytes from pluripotent stem cells have informed similar studies with nonhuman primate and human cells, but differences among species are clear. IVG has great potential for reproductive medicine, including novel diagnosis and modeling of infertility. The realization of human IVG requires further intensive efforts, but as technical hurtles are overcome, careful consideration must be given to the potential application of methods for reproductive purposes. —BAP
Scientists produce genetically engineered, cloned pigs for xenotransplantation
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1171992/
"Two groups of scientists have produced genetically engineered, cloned pigs whose tissue may be suitable for transplanting into humans. Both teams have reported having bred pigs that lack the gene that causes rejection. PPL Therapeutics, which is based in Edinburgh, has produced five pigs that lack the gene, while Immerge BioTherapeutics and a team from the University of Missouri-Columbia have cloned miniature pigs with the gene "knocked out" of their DNA. "
Cloning of Macaque Monkeys by Somatic Cell Nuclear Transfer
"Generation of genetically uniform non-human primates may help to establish animal models for primate biology and biomedical research. In this study, we have successfully cloned cynomolgus monkeys (Macaca fascicularis) by somatic cell nuclear transfer (SCNT). We found that injection of H3K9me3 demethylase Kdm4d mRNA and treatment with histone deacetylase inhibitor trichostatin A at one-cell stage following SCNT greatly improved blastocyst development and pregnancy rate of transplanted SCNT embryos in surrogate monkeys. For SCNT using fetal monkey fibroblasts, 6 pregnancies were confirmed in 21 surrogates and yielded 2 healthy babies. For SCNT using adult monkey cumulus cells, 22 pregnancies were confirmed in 42 surrogates and yielded 2 babies that were short-lived. In both cases, genetic analyses confirmed that the nuclear DNA and mitochondria DNA of the monkey offspring originated from the nucleus donor cell and the oocyte donor monkey, respectively. Thus, cloning macaque monkeys by SCNT is feasible using fetal fibroblasts.
"
Chinese scientist who edited babies' genes jailed for three years
"A Chinese court has sentenced He Jiankui, the scientist who sparked global controversy last year when he claimed to have created the world’s first “gene-edited” children, to three years in prison for violating medical regulations.
He shocked the scientific community when he announced at a conference in Hong Kong that he had created genetically modified twin sisters, dubbed Lulu and Nana, and that a third child was on the way.
The court in Shenzhen found He guilty of “illegal medical practices” and in addition to the prison sentence fined him 3m yuan (£327,360), according to the state news agency, Xinhua. Two others on He’s research team received lesser fines and sentences."
"If you asked a room of cell biologists 5 years ago if cell culture media could productively grow cells while costing just $0.63 per liter, you would have been laughed out of it. No longer.
Let's dive into this important study that poses challenges for #cultivatedmeat skeptics:"
https://x.com/elliotswartz/status/1832937846467936516
Researchers Overcome Major Barrier in Artificial Placenta Research
"Although heparin is routinely used in extracorporeal membrane oxygenation therapy, there are special considerations when developing an extracorporeal artificial placenta.
Extremely low gestational age newborns – born before 28 weeks – are at high risk for brain bleeding due to organ immaturity. Thinning of the blood with heparin would create a prohibitively high risk of bleeding and remained a critical milestone to human use of the artificial placenta.
So, the research team developed a new solution that didn’t require blood thinning – a special coating was applied to the circuit that releases nitric oxide to prevent clotting while avoiding systemic anticoagulation.
And it worked. This innovative strategy allowed the artificial placenta to safely support premature sheep without systemic anticoagulation for one week without bleeding or clotting, according to new research in Pediatric Research.
...
The innovative approach, known as nitric oxide surface anticoagulation, referred to as NOSA, is the culmination of decades of research led by Robert Bartlett, M.D., an active emeritus professor of surgery at U-M who led the development of modern ECMO, and Mark Meyerhoff, Ph.D., a U-M professor of chemistry."
Creation of a synthetic amniotic fluid for use in fetal therapy
"Amnioinfusion fluid during fetal interventions (saline or Ringer’s) is more acidic and nutrient poor than amniotic fluid. We created a synthetic amniotic fluid for use in fetal therapy and evaluated it's impact upon amniotic epithelium in vitro."
https://www.ajog.org/article/S0002-9378(22)00904-8/fulltext
Scientists create a part-human, part-pig embryo — raising the possibility of interspecies organ transplants
"For the first time, scientists have grown an embryo that is part-pig, part-human.
The experiment, described Thursday in the journal Cell, involves injecting human stem cells into the embryo of a pig, then implanting the embryo in the uterus of a sow and allowing it to grow. After four weeks, the stem cells had developed into the precursors of various tissue types, including heart, liver and neurons, and a small fraction of the developing pig was made up of human cells.
The human-pig hybrid — dubbed a “chimera” for the mythical creature with a lion's head, a goat's body and a serpent's tail — was “highly inefficient,” the researchers cautioned. But it's the most successful human-animal chimera and a significant step toward the development of animal embryos with functioning human organs."
Interspecies Implantation and Mitochondria Fate of Panda-Rabbit Cloned Embryos
https://web.archive.org/web/20150923202940/http://www.biolreprod.org/content/67/2/637.long
https://en.wikipedia.org/wiki/Interspecific_pregnancy
"In this experiment, nuclei from cells taken from abdominal muscles of giant pandas were transferred to egg cells of rabbits and, in turn, transferred into the uterus of cat together with cat embryos. Concomitant use of SCNT and interspecific pregnancy has also been speculated to potentially recreate the mammoth species, for example by taking genetic material from mammoth specimens preserved in permafrost and transferring it into egg cells and subsequently the uterus of an elephant.[16][17]"
Next steps for the xenotransplantation of pig organs into humans
"Pigs offer a potentially plentiful supply of organs for humans, but widespread xenotransplantation will require a collaborative and iterative approach to research, as well as involvement of transplant patients and the public."