![]() ![]() In dispermic chimeras, two eggs that have been fertilized by two sperm fuse together, producing a so-called tetragametic individual-an individual originating from four gametes, or sex cells. (For information on the phenomenon in plants, see chimera.) Included among the different known types of animal chimeras are dispermic and twin chimeras, microchimeras, and parthenogenetic and androgenetic chimeras. Chimeras are distinguished from mosaics, organisms that contain genetically different populations of cells originating from a single zygote, and from hybrids, organisms containing genetically identical populations of cells originating from a cross of two different species. The term is derived from the Chimera of Greek mythology, a fire-breathing monster that was part lion, part goat, and part dragon. SpaceNext50 Britannica presents SpaceNext50, From the race to the Moon to space stewardship, we explore a wide range of subjects that feed our curiosity about space!Ĭhimera, in genetics, an organism or tissue that contains at least two different sets of DNA, most often originating from the fusion of as many different zygotes (fertilized eggs).Learn about the major environmental problems facing our planet and what can be done about them! Saving Earth Britannica Presents Earth’s To-Do List for the 21st Century.Britannica Beyond We’ve created a new place where questions are at the center of learning.100 Women Britannica celebrates the centennial of the Nineteenth Amendment, highlighting suffragists and history-making politicians. CHIMERA PEOPLE HOW TOCOVID-19 Portal While this global health crisis continues to evolve, it can be useful to look to past pandemics to better understand how to respond today.Student Portal Britannica is the ultimate student resource for key school subjects like history, government, literature, and more.This Time in History In these videos, find out what happened this month (or any month!) in history.#WTFact Videos In #WTFact Britannica shares some of the most bizarre facts we can find.Demystified Videos In Demystified, Britannica has all the answers to your burning questions.Britannica Explains In these videos, Britannica explains a variety of topics and answers frequently asked questions.Britannica Classics Check out these retro videos from Encyclopedia Britannica’s archives.The oldest woman to have fetal cells in her brain was 94 years old, suggesting that these cells can sometimes stay in the body for a lifetime. They found that 63 percent of these women had traces of male DNA from fetal cells in their brains. In a 2012 study, researchers analyzed the brains of 59 women ages 32 to 101, after the women had died. In some cases, fetal cells may stay in a woman's body for years. The researchers knew that the cells were from the fetus, and not from the mother, because the cells contained a Y chromosome (found only in males) and all of the women had been carrying sons. The study found that the women had fetal cells in all of these tissues. The researchers tested tissue samples from the kidneys, livers, spleens, lungs, hearts and brains of 26 women who died while pregnant or within one month of giving birth. This can happen when a woman becomes pregnant and a small number of cells from the fetus migrate into her blood and travel to different organs.Ī 2015 study suggested that this happens in almost all pregnant women, at least temporarily. More commonly, people may exhibit so-called microchimerism - when a small fraction of their cells are from someone else. A blood transfusion will also temporarily give a person cells from someone else, but in a bone marrow transplant, the new blood cells are permanent, according to the Tech Museum of Innovation in San Jose, California. ![]() But in other cases, recipients may have a mix of both their own blood cells and donor ones, according to a 2004 review paper (opens in new tab) in the journal Bone Marrow Transplantation. In some cases, all of the blood cells in a person who received a bone marrow transplant will match the DNA of the donor. ![]()
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