Genome complexity: enzyme controls chromosome knots (Introduction)

by David Turell , Wednesday, February 02, 2022, 19:24 (807 days ago) @ David Turell

Very important to proper reproduction:

https://www.sciencedaily.com/releases/2022/02/220202111811.htm

"A research team, led by the John Innes Centre found that the enzyme DNA topoisomerase VI (topo VI) performs a critical role in removing chromosome tangles that occur in the cell nucleus of plants.

"This function enables the process of endoreduplication where the DNA content is doubled. Endoreduplication is the source of polyploidy, where a plant has multiple sets of chromosomes, including in some major crops.

"Topo VI was discovered, many years ago, in archaea, a type of single-celled organism without a nucleus. It was only found in plants and parasites such as malaria, more recently leading to the scientific question: what is the function of this enzyme in eukaryotes, organisms whose cells contain a nucleus?

"'Our study shows that topo VI in plants functions to remove chromosome tangles that occur during the endoreduplication process. This potentially explains its presence in plants where during endoreduplication, entanglements are most likely to occur," explains lead author Dr Shannon McKie."

Comment: My usual point: enzymes are giant complex working molecules necessary for life. Thisone was first found in Archaea so it had to have appeared with the first DNA, and must have been designed in anticipation of tangle problems. God knew there could be errors.