Centromere sequence-independent but biased loading of subgenome-specific CENH3 variants in allopolyploid Arabidopsis suecica

• Published in: Plant molecular biology Vol. 114; no. 4; p. 74
• Main Authors: Karimi-Ashtiyani, Raheleh, Banaei-Moghaddam, Ali Mohammad, Ishii, Takayoshi, Weiss, Oda, Fuchs, Jörg, Schubert, Veit, Houben, Andreas
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.08.2024; Springer Nature B.V
• Subjects: Arabidopsis - genetics; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis suecica; Biochemistry; Biomedical and Life Sciences; Centromere - genetics; Centromeres; Chromosomes; Gene Expression Regulation, Plant; Genes; Genome, Plant - genetics; Genomes; Histone H3; Histones; Histones - genetics; Histones - metabolism; Hybrids; Life Sciences; Localization; Molecular biology; Nucleosomes; Plant Pathology; Plant Sciences; Polyploidy; Centromere plasticity; Uniparental chromosome elimination; Allopolyploidization; Haploid; CENH3; Species evolution
• ISSN: 0167-4412; 1573-5028; 1573-5028
• DOI: 10.1007/s11103-024-01474-5

Centromeric nucleosomes are determined by the replacement of the canonical histone H3 with the centromere-specific histone H3 (CENH3) variant. Little is known about the centromere organization in allopolyploid species where different subgenome-specific CENH3s and subgenome-specific centromeric sequences coexist. Here, we analyzed the transcription and centromeric localization of subgenome-specific CENH3 variants in the allopolyploid species Arabidopsis suecica. Synthetic A. thaliana x A. arenosa hybrids were generated and analyzed to mimic the early evolution of A. suecica . Our expression analyses indicated that CENH3 has generally higher expression levels in A. arenosa compared to A. thaliana , and this pattern persists in the hybrids. We also demonstrated that despite a different centromere DNA composition, the centromeres of both subgenomes incorporate CENH3 encoded by both subgenomes, but with a positive bias towards the A. arenosa -type CENH3. The intermingled arrangement of both CENH3 variants demonstrates centromere plasticity and may be an evolutionary adaption to handle more than one CENH3 variant in the process of allopolyploidization.