How to mask in Illustrator then use in After Affects aswell

I am trying to do this tutorial http://ift.tt/ZD5mFA. Basically it has a circle and uses a mask to create holes in it and animate it. I was wondering if I could import circles from illustrator with masks over it and animate it as well. If so could someone tell me how I can make the mask in Illustrator as well which I can animate in AE. Thank you