Figure 3. Expression of
lin-12::lacZ and
lag-2::lacZ in Z1.ppp and Z4.aaa in
lin-12(+) Hermaphrodites. Open arrow indicates Z1.ppp; solid arrow indicates Z4.aaa. Preforming, forming, and formed refer to the morphology of the gonad primordium (see description in text): preforming, Ll molt/early L2 stage; forming, mid-late L2 stage; formed, L2 molt. Anterior is to the left. All preforming and forming primordia are shown from a ventral view; in forming primordia, the identities of the nonstaining cells is inferred by their position relative to other somatic gonadal cells and to the anterior-posterior and left-right axes. Formed primordia are shown from a dorsal view; in the primordia shown, Zi .ppp has become the AC. The
lin-12:lacZ reporter gene is also expressed in Z1.ppa and Z4.aap. Here, in the pictures of the forming stage, expression in Z1.ppa is visible in this plane of focus, and in the pictures of the preforming and formed stages, expression in Z4.aap is visible.
lin-12 activity influences, but is not absolutely required to specify, the fates of Z1.ppa and Z4.aap in the L2 stage (Greenwald et al., 1983; Seydoux et al., 1990). Other cells stain in other planes of focus (Wilkinson, 1994), and can sometimes be seen as dark areas in the photograph. A complete description of the spatial and temporal pattern of
lin-12 expression in hermaphrodites will be described elsewhere (Wilkinson, 1994; H. A. W. and I. G., unpublished data).Complete genotypes:
uric-54 smg-1; arIs11 [
lin-12::lacZ] or
unc-54 smg-1; arIs13[
lag-2::lacZ].