Centromeres under Pressure: Evolutionary Innovation in Conflict with Conserved Function

Area of Science:

• Genetics
• Evolutionary Biology
• Molecular Biology

Background:

• Centromeres are essential for accurate chromosome segregation during cell division.
• Despite conserved function, centromeres exhibit remarkable evolutionary diversity in DNA, size, and organization.
• Features include rapidly evolving DNA, diverse structures, repetitive arrays, neocentromere formation, and sequence-driven fragility.

Purpose of the Study:

• To review current understanding of centromere evolution and plasticity.
• To detail mutagenic processes shaping centromere genetic diversity.
• To explore the origins of dynamic centromere features beyond centromere drive.

Main Methods:

• Literature review of centromere evolution.
• Analysis of proposed mutagenic processes.
• Synthesis of findings on centromere plasticity and function.

Main Results:

• Centromere DNA evolves rapidly, driven by "selfish" centromere drive for biased meiotic transmission.
• Mutagenic processes contribute to homogenized repetitive arrays and diverse centromere organization.
• Centromeres display plasticity, including neocentromere formation and sequence-derived fragility.

Conclusions:

• Centromere evolution involves ongoing, dynamic shifts, not just static relics.
• These shifts promote centromere flexibility but can compromise integrity, leading to genome instability.
• Understanding these processes is crucial for comprehending both normal cell function and pathological conditions.