Biological complexity: cell division DNA controls (Introduction)

by David Turell , Friday, December 27, 2019, 18:17 (1793 days ago) @ dhw

The division must be evenly split into new cells for cellular DNA, Controls are very tight:

https://phys.org/news/2019-12-insight-cells-dna.html

"During cell division our chromosomes, containing a duplicated set of DNA, must be split equally between the newly created daughter cells. To ensure this equal segregation of DNA, chromosomes must be correctly attached to microscopic rope-like structures, known as microtubules, which pull them apart.

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"'We discovered that Astrin arrives at the attachment site with an enzyme called PP1 when proper attachments have been made. Together these proteins rapidly secure attachments so the attachment site is able to resist pulling forces, which are separating the DNA apart. This protein complex only acts on correct attachments, which helps make sure cells end up with the right number of chromosomes after cell division."

"Dr. Duccio Conti, postdoctoral researcher at Queen Mary and first author of the paper, added, "Whilst we originally thought Astrin would be important to cement attachments, we were surprised to find that it actually works as a dynamic lock, ensuring attachments are not stabilised prematurely."

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"Professor Richard Pickersgill, professor of structural biology and head of the School of Biological and Chemical Sciences at Queen Mary, said: "Right now our cells are dividing to replace lost and damaged cells; it's a wonderful process essential for life but also incredibly complex—over 100 proteins are involved in orchestrating the organisation and segregation of chromosomes alone. There is much still to discover about the detailed mechanism of chromosome segregation, but this work, which explains the role of Astrin in strengthening microtubule attachments, is an important milestone along the way.'" (my bold)

Comment: Note my bold. Over 100 specific proteins are involved. Not a chance development if that many specific proteins are involved. Designed.