Biotechnology Building Cornell University Ithaca, NY 14853 zyg-1 mutations disrupt cell divisions in the early C. elegans embryo as well as in the vulval lineage.
Mutant embryos show two types of spindle formation defects.
In two alleles, many embryos have multipolar first divisions. Tubulin staining has shown extra centrosomes around the male pronucleus as early as the midpronuclear stage. The abnormal nuclei in these cells continue to break down at regular intervals however, suggesting that at least some aspects of the normal cell cycle are still functioning in zyg-1 embryos. Embryos arrest with fewer than 50 cells. All five alleles show an increased penetrance of this Egl phenotype when heterozygous with ccDf5, a deficiency which deletes zyg-1.