Responding to Rutgers biologist Dan Stern Cardinale (aka Dr. Dan), David Klinghoffer wrote here (see, “Dr. Dan Has a Taste for Debate”):
From what I’ve been told, there are many examples of “non-conserved” regions having sequence-independent functions. Compare two strains of yeast, and they will often have almost no sequence identity between centromeric regions. Yet these regions are essential because this is where kinetochore is formed and spindle attachment occurs. There are many other examples. Is it not so?
It is so. Some documentation might be welcome, however. How about it?
No problem. A very typical (metazoan) example is provided by Drosophila where each chromosome has its own kinetochoric DNA sequence, and where these are species-specific:
- Kyriacou E, Heun P. 2023. Centromere structure and function: lessons from Drosophila. Genetics 225(4).
- Chang CH, Chavan A, Palladino J, Wei X, Martins NMC, Santinello B, Chen CC, Erceg J, Beliveau BJ, Wu CT, Larracuente AM, Mellone BG. 2019. Islands of retroelements are major components of Drosophila centromeres. PLoS Biology 17(5): e3000241.
For the yeast genus Candida see:
- Sanyal K, Baum M, Carbon J. 2004. Centromeric DNA sequences in the pathogenic yeast Candida albicans are all different and unique. Proc Natl Acad Sci U S A. 101(31): 11374-11379.
- Baum M, Sanyal K, Mishra PK, Thaler N, Carbon J. 2006. Formation of functional centromeric chromatin is specified epigenetically in Candida albicans. Proc Natl Acad Sci U S A. 103(40): 14877-14882.
Then again there is ample evidence that centromere identity is imposed top-down (as in Schizosaccharomyces):
- Wu W, McHugh T, Kelly DA, Pidoux AL, Allshire RC. 2022. Establishment of centromere identity is dependent on nuclear spatial organization. Curr Biol. 32(14):3121-3136.e6.
We hope Professor Stern Cardinale finds these citations of interest.