IF YOUR sperm or eggs contained genes from another individual, how would you feel about your offspring? This is the extraordinary situation facing marmosets, in which such germ line chimerism has been identified for the first time.
Wied’s black tufted-ear marmosets (Callithrix kuhlii) are unusual in that a high proportion of pregnancies result in fraternal twins, and most of those are chimeras. Genetic analysis of the twins shows that all tissues – including skin, hair, brain, lung and muscle – may contain cells from their sibling. It happens early in development when the placentas of the twins fuse and…
