Organism that contains a mixture of genetically different cells.
An organism consisting of tissues or parts of diverse genetic constitution. An example of a chimera would be a centaur; the half-man, half-goat figure of Greek mythology. The word “chimera” is from the mythological creature by that name which possessed the head of a lion, the body of a goat, and the tail of a serpent. The word chimera is very general and may be applied to any number of entities. For example, chimeric antibodies may be produced by cell cultures in which the variable, antigen-binding regions are of murine (mouse) origin while the rest of the molecule is of human origin. It is hoped that this combination will lead to an antibody which, when injected, would not give rise to a lesser immune response by the host.
A mixture of tissues or genetically different constitution in the same part of an organism. It may result from mutation, irregular mitosis, somatic crossing over or an artificial fusion may be preclinical with parallel layers of genetically different tissues, or sectorial.
Double-egg twin whose blood cells have mixed during development with those of the other twin; prior to the mix, each twin had a different blood type. Following the mix, each now has a combination type (mixed type). Recently, one hospital performed the first combined kidney and bone marrow transplantation to treat multiple myeloma. Chimerism of the bone marrow was deliberately induced, meaning that the patient’s new blood cells were a mix of her previous type and the donor type. Since she received the bone marrow transplant in the first place because her own bone marrow was devoid of any cells, her new blood and tissue type is now functionally the same as the donor. The result was complete remission of the multiple myeloma, as well as a markedly reduced need for immunosuppressive drugs.
Chimera is an organism, whether plant, animal or human, in which there are at least two kinds of tissue differing in their genetic constitution.
A chimera is a botanical entity, which is composed of diverse genetic tissues due to the occurrence of grafting, somatic mutation, or similar biological events. The plant structure manifests itself in two ways: first, as separate germinal layers in the apical meristem, giving rise to periclinal and mericlinal chimaeras, where one tissue is either wholly or partially enclosed by a “skin” of the other. Second, as distinct segments involving all layers of the apical meristem, which give rise to sectorial chimaeras.