| From the series "Weird Or What" first broadcast 6-9-10. Two separate fertilized eggs can fuse together in utero, eventually forming what is essentially one person with two completely different sets of DNA. Lydia Fairchild is one such "Chimera". Her blood, saliva and certain other parts of her body have one set of genes, while her ovaries, uterus, and other parts have another. This means any children she might have will share their father's DNA, but only one set of hers. From Wikipedia: "Tetragametic chimerism is a form of congenital chimerism. This condition occurs through the fertilization of two separate ova by two sperm, followed by the fusion of the two at the blastocyst or zygote stages. This results in the development of an organism with intermingled cell lines. Put another way, the chimera is formed from the merging of two nonidentical twins in a very early (zygote or blastocyst) phase. As such, they can be male, female, or hermaphroditic. As the organism develops, it can come to possess organs that have different sets of chromosomes. For example, the chimera may have a liver composed of cells with one set of chromosomes and have a kidney composed of cells with a second set of chromosomes. This has occurred in humans, and at one time was thought to be extremely rare, though more recent evidence suggests that it is not as rare as previously believed." |
