Comparative centromere genomics reveals evolutionary divergence in Solanaceae genomes

Area of Science:

• Genomics
• Molecular Biology
• Evolutionary Biology

Background:

• Centromeres are crucial for accurate chromosome segregation during cell division.
• Their repetitive DNA has historically hindered large-scale characterization.
• Advances in long-read sequencing facilitate centromere evolution studies.

Purpose of the Study:

• To generate near-telomere-to-telomere genome assemblies for eggplant, African eggplant, and wild pepper.
• To delineate functional centromeric chromatin using CENH3 ChIP-seq in various Solanaceae species.
• To investigate the evolution and diversification of centromeres in Solanaceae crops.

Main Methods:

• Near-telomere-to-telomere genome assembly using long-read sequencing.
• Chromatin immunoprecipitation sequencing (ChIP-seq) for CENH3.
• Comparative genomics analysis of centromere composition and organization.

Main Results:

• Solanaceae centromeres are primarily composed of Ty3/Gypsy LTR retrotransposons, with species-specific variations.
• Centromere size correlates with genome size across Solanaceae crops.
• Frequent centromere shifts and rapid synteny decay around centromeres were observed.
• Intra-species centromere haplotype variation exists, notably in African eggplant.

Conclusions:

• Centromeres in Solanaceae crops exhibit dynamic evolution and significant within-species variation.
• Distinct, species-specific centromere organizational patterns were identified.
• Solanaceae serves as a valuable model for comparative plant centromere evolution research.