Trisomies in the mouse

During the 1970s, A. Gropp and co-workers investigated
the effect of trisomies on the
development of the mouse. Trisomic mice, resulting
from the segregation of translocations,
had a developmental profile and certain morphological
changes characteristic for each
trisomy (1). Embryos with a chromosome
missing (monosomies) died very early in gestation.
(Figure fromA. Gropp, 1982). Amouse embryo
with trisomy 12 shows an open skull cap
and other malformations on the 14th day of
development (2), unlike other embryos of the
same age (H.Winking, Lübeck, 1991; Boué et al.,
1985). Only trisomy 19 is compatible with survival
until birth (day 21), but the brain is too
small (3). These animals die shortly after birth.