A Semi-Dominant Mutation in the General Splicing Factor SF3a66 Causes Anterior-Posterior Axis Reversal in One-Cell Stage C. elegans Embryos: e106484

• Published in: PloS one 2014-09, Vol.9 (9)
• Main Authors: Keikhaee, Mohammad R, Nash, Eric B, Bowerman, Bruce
• Format: Article
• Language: English
• Subjects: Caenorhabditis elegans
• ISSN: 1932-6203
• DOI: 10.1371/journal.pone.0106484

Establishment of anterior-posterior polarity in one-cell stage Caenorhabditis elegans embryos depends in part on astral microtubules. As the zygote enters mitosis, these microtubules promote the establishment of a posterior pole by binding to and protecting a cytoplasmic pool of the posterior polarity protein PAR-2 from phosphorylation by the cortically localized anterior polarity protein PKC-3. Prior to activation of the sperm aster, the oocyte Meiosis I and II spindles assemble and function, usually at the future anterior pole, but these meiotic spindle microtubules fail to establish posterior polarity through PAR-2. Here we show that a semi-dominant mutation in the general splicing factor SF3a66 can lead to a reversed axis of AP polarity that depends on PAR-2 and possibly on close proximity of oocyte meiotic spindles with the cell cortex. One possible explanation is that reduced levels of PKC-3, due to a general splicing defect, can result in axis reversal due to a failure to prevent oocyte meiotic spindle microtubules from interfering with AP axis formation.