Heterozygotes are WT and segregate WT, Uncs and Rollers. or78 zygotic effects: Pv, mild Unc, many explode at vulva upon reaching adulthood. or78 maternal effects: endoderm (E) transformed into mesoderm (MS) in early embryo, severe morphogenesis defect. mig-14, mom-3, pvl-2, and let-553 are the same gene.