Required for the normal migration of longitudinal and peripheral glial cells. During larval development, required for the migration of the subretinal glia into the eye disk. During embryonic development, also controls the migration of muscle cells toward their attachment sites. Required in the mesoderm for the correct morphogenesis of embryonic gonad and for tracheal branch fusion during tracheal development. Shg may be cooperating with foi to mediate a common mechanism for gonad and tracheal morphogenesis. Acts as a zinc transporter in both yeast and mammalian cells. Maternal foi has almost completely disappeared by embryonic stage 3 except in the pole cells. In stage 6 embryos, expression is enriched in the invaginating mesoderm. In stage 9 embryos, high levels in the anterior and posterior midgut primordia. In stage 14 embryos, broad expression with low levels in the epidermis. Expressed both maternally and zygotically. Glycosylated. Belongs to the ZIP transporter (TC 2.A.5) family.