Creating spatial information at the correct time and location is a necessity for the developing organism. The cytoplasmic gradient of the RNA-binding protein MEX-5 in the C. elegans zygote is a prototypical example of spatiotemporal control of cell fate through concentration gradients. MEX-5 gradient depends on PAR-1 location, and forms through differential-diffusion, a mechanism that relies on a difference in the velocities of a fast and slow form of the protein. Preliminary data indicate that MEX-6, the paralogue of MEX-5, could also form a gradient through a differential-diffusion mechanism, despite MEX-6 diffusion coefficients being two times slower than MEX-5. I aimed to describe the temporal dynamics of MEX-6 gradient establishment using live imaging of fluorescence-tagged strains and computational simulations. I show that a differential-diffusion mechanism contribute to MEX-6 gradient establishment. Additionally, my work reveals that PAR polarity can be affected by impairment of the PLK-1 interaction with MEX-5 and MEX-6.