Chimaeras

About Chimaeras

• A genetic chimaera is a single organism composed of cells of more than one distinct genotype (or genetic makeup).
• The animal kingdom has several examples of varying degrees of chimerism.
  • The half-sider budgerigar, a type of common parakeet widely adopted as pets, has different colours on either side of its body due to chimerism.
  • Anglerfish: The male fish fuses with and is eventually absorbed into the female fish, mixing their genetic makeups into a single animal.
  • Marine sponges are known to have up to four distinct genotypes in a single organism.
• Natural chimaeras among humans
  • They occur when the genetic material in one cell changes and gives rise to a clonal population of cells different from all the other cells.
  • The fusion of two fertilised zygotes early in the embryonic stage can also lead to a condition in which two genetic makeups coexist in a single individual.
  • Chimerism can also result from twin or multiple pregnancies evolving into a single foetus or a twin foetus being absorbed into a singleton.

Q1) What is Zygote?

It is a fertilized egg cell that results from the union of a female gamete (egg, or ovum) with a male gamete (sperm). In the embryonic development of humans and other animals, the zygote stage is brief and is followed by cleavage, when the single cell becomes subdivided into smaller cells.

Source: The chimaeras of nature and their promise to grow human organs | Explained