Absence of expression in parthenogenetic sheep fetuses suggests paternal expression (Feil
R et al, 1998). PEG1 isoform 2 expression in day 21 parthenogenetic fetuses was 0.04-fold that
of control fetuses indicating predominant paternal expression. In parthenogenetic chorioallantois
PEG1 isoforms 1 and 2 expression levels were 0.02
and 0.03-fold that of controls (Thurston
A et al 2008).