Expression of
mig-2::GFP was first detected in early embryos, prior to the onset of morphogenesis (~300 min after first cell cleavage). At this time, expression was seen in nearly every cell with the exception of the intestine. At hatching, many but not all cell types expressed the fusion protein. In particular,
mig-2::GFP was expressed in cells that undergo long-range migration during embryogenesis, such as the neurons HSN, CAN, and ALM. Expression was quite strong in the Q cells and their descendants during their migrations in the first larval stage. Expression in these neurons persisted through development. Many mesodermal cells, such as the embryonic migratory cells Z1 and Z4, also expressed
mig-2::GFP, although one migratory mesodermal cell, M, did not. Weaker
mig-2::GFP expression was also seen in many nonmigratory neurons and epidermal cells; however, no expression was detected in the intestine or germ line. In older larvae and adult hermaphrodites, expression was seen in the vulva, distal tip cells of the gonad, and the sex myoblasts and their descendants. Similar patterns of expression were seen in two additional independently isolated transgenic lines.