IGF2 is paternally expressed in sheep, but biallelic in adult sheep liver (as seen in humans)(McLaren
RJ et al, 1999). Additional evidence for imprinting was provided by underexpression in sheep
gynogenetic allantoic and trophoblastic tissue (Hagemann
LJ et al, 1998).
Upstream of H19, methylation was exclusively on the paternal allele consistent with paternal
expression of IGF2 (Young
LE A et al 2003).
IGF2 expression levels in parthenogenetic 21 day fetuses was 0.04 times that of control fetuses,
consistent with paternal expression. In parthenogenetic chorioallantois it was 0.07-fold that of
A et al 2008).