Figure 4. Maternal expression of
nhr-23 detected by in situ hybridization. A
nhr-23 antisense DNA probe was hybridized to an extruded adult gonad courtesy of B. Harfe and A. Fire (Seydoux and Fire, 1995; Harfe and Fire, 1998). Strong hybridization is seen throughout the gonad and in forming oocytes (small arrows). Weaker expression is detected in embryos until the 4-cell stage (arrowhead) after which it is undetectable in early embryos (e.g. embryos with asterisk). A weak hybridization signal is detected again in late stage embryos after the bean stage of embryogenesis (not shown, see text). Bar, ~10 µm.