par-6, a gene involved in the establishment of asymmetry in early C. elegans embryos, mediates the asymmetric localization of PAR-3.
The generation of asymmetry in the one-cell embryo of Caenorhabditis elegans is necessary to establish the anterior-posterior axis and to ensure the proper identity of early blastomeres. Maternal-effect lethal mutations with a partitioning defective phenotype (par) have identified several genes involved in this process. We have identified a new gene, par-6, which acts in conjunction with other par genes to properly localize cytoplasmic components in the early embryo. The early phenotypes of par-6 embryos include the generation of equal-sized blastomeres, improper localization of P granules and SKN-1 protein, and abnormal second division cleavage patterns. Overall, this phenotype is very similar to that caused by mutations in a previously described gene, par-3. The probable basis for this similarity is revealed by our genetic and immunolocalization results; par-6 acts through par-3 by localizing or maintaining the PAR-3 protein at the cell periphery. In addition, we find that loss-of-function par-6 mutations act as dominant bypass suppressors of loss-of-function mutations in par-2.
Watts
J L
JL
Section of Genetics and Development, Cornell University, Ithaca, New York 14853, USA.
Etemad-Moghadam
B
B
Guo
S
S
Boyd
L
L
Draper
B W
BW
Mello
C C
CC
Priess
J R
JR
Kemphues
K J
KJ
D000483:Alleles; D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000235:genetics / Q000502:physiology; D029742:Caenorhabditis elegans Proteins; D002970:Cleavage Stage, Ovum; D004330:Drosophila; D015801:Helminth Proteins / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D013489:Suppression, Genetic
D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins; C087977:par-2 protein, C elegans; C097238:PAR-3 protein, C elegans; D017346:Protein Serine-Threonine Kinases