I know that microtubules build up and break down at the plus end, and I think only at the plus end (I’m not sure). I’m just wondering how can they break off/shrink during cell division (and pull the chromosomes apart) while they’re stuck on the chromosomes with their plus end?
I put this question to my cell biology teacher, but he didn’t know the answer. I hope you know!
Answer
Dear Jannique,
There are 2 types of microtubules found in the dividing cell: microtubules from one pole to the other and microtubules that are half as long and carry a chromosome from the equatorial plane to the poles. The latter microtubules ‘crawl’, as it were, over the former to allow the chromosome to migrate. They do this by means of other proteins (MAPs: Microtubule Associated Proteins) that hook and change shape (with the consumption of ATP cfr. muscle action). At the pole, the microtubule will then disintegrate into subunits to make room for the following pieces.
kind regards,
Answered by
ir. Myriam Meyers
industrial microbiology and biochemistry
Old Market 13 3000 Leuven
https://www.kuleuven.be/
.