Investigators found that cyclin B concentration rises and fa

Investigators found that cyclin B concentration rises and falls in synchrony with mitotic events and MPF activity. However, correlation is not causality. How did they show that cyclin B was responsible for these cell-cycle events?

Solution

ANSWERS : Cyclin B was responsible for the rise and fall in MPF activity synchronous with mitotic events, Murray and krischner treated xenopus extract with RNase and showed that this blocked entry into mitosis. Upon addition of only cyclin B m RNA, mitotic entry was restored, indicating that synthesis of the cyclin B protein in sufficient to drive the extract into M-phase