Added heterochromatin segments in chromosomes of squirrel monkeys (Saimiri sciureus)

Variant structural homozygosity, observed previously only in plants and insects, is reported herein for the first time in mammalian chromosomes. The addition of a heterochromatic chromosome segment to either one or both homologues is described in autosomes B5 and B12 of the squirrel monkey, Saimiri sciureus.