Cell polarity is required at many different stages of development, including early embryogenesis and organogenesis. Intercellular junctions are believed to be required to polarize epithelial cells. PAR-3/PKC-3/PAR-6 complex, which serves as one of the earlist polarity cues during the early embryogenesis in C. elegans , has been found to be localized at apical junctions of gut epithelium in C. elegans , Drosophila , and mammals. However, the function of PAR-3/PKC-3/PAR-6 in establishment and maintenance of epithelial cell polarity in C. elegans has not been studied, mainly because the loss of function of this protein complex perturbs early embryogenesis. I am trying to overcome this barrier in two different ways. Heat shock-induced
par-3 RNAi, right after early embryogenesis will deplete
par-3 mRNA and hopefully will result in
par-3 knock-out phenotypes in late embryos or L1~L2 larvae. Alternatively, I am examining the effect of a mutation in
pkc-3 on epitheial polarity. I have a
pkc-3 mutant, which is newly generated by Vancouver Gene Knockout Lab. This mutant carries a 1.5kb deletion (
ok544 ) that removes kinase domain. Homozygotes undergo normal embryogenesis due to maternal contribution, but they are arrested as L2 larvae. Currently I am trying to optimize the heat shock conditions for
par-3 RNAi, and to identify the phenotypes of arrested
pkc-3 mutants.