Centromere inactivation and epigenetic modifications of a plant chromosome with three functional centromeres
- First Online:
- 489 Downloads
A chromosome with two functional centromeres is cytologically unstable and can only be stabilized when one of the two centromeres becomes inactivated via poorly understood mechanisms. Here, we report a transmissible chromosome with multiple centromeres in wheat. This chromosome encompassed one large and two small domains containing the centromeric histone CENH3. The two small centromeres are in a close vicinity and often fused as a single centromere on metaphase chromosomes. This fused centromere contained approximately 30% of the CENH3 compared to the large centromere. An intact tricentric chromosome was transmitted to about 70% of the progenies, which was likely a consequence of the dominating pulling capacity of the large centromere during anaphases of meiosis. The tricentric chromosome showed characteristics typical to dicentric chromosomes, including chromosome breaks and centromere inactivation. Remarkably, inactivation was always associated with the small centromeres, indicating that small centromeres are less likely to survive than large ones in dicentric chromosomes. The inactivation of the small centromeres also coincided with changes of specific histone modifications, including H3K27me2 and H3K27me3, of the pericentromeric chromatin.
- Cardone MF, Alonso A, Pazienza M, Ventura M, Montemurro G, Carbone L, de Jong PJ, Stanyon R, D'Addabbo P, Archidiacono N, She XW, Eichler EE, Warburton PE, Rocchi M (2006) Independent centromere formation in a capricious, gene-free domain of chromosome 13q21 in Old World monkeys and pigs. Genome Biol 7:R91CrossRefPubMedGoogle Scholar
- Gill BS, Friebe B, Endo TR (1991) Standard karyotype and nomenclature system for description of chromosome bands and structural aberrations in wheat (Triticum aestivum). Genome 34:830–839Google Scholar
- Qi LL, Echalier B, Chao S, Lazo GR, Butler GE, Anderson OD, Akhunov ED, Dvorak J, Linkiewicz AM, Ratnasiri A, Dubcovsky J, Bermudez-Kandianis CE, Greene RA, Kantety R, La Rota CM, Munkvold JD, Sorrells SF, Sorrells ME, Dilbirligi M, Sidhu D, Erayman M, Randhawa HS, Sandhu D, Bondareva SN, Gill KS, Mahmoud AA, Ma XF, Miftahudin GJP, Conley EJ, Nduati V, Gonzalez-Hernandez JL, Anderson JA, Peng JH, Lapitan NLV, Hossain KG, Kalavacharla V, Kianian SF, Pathan MS, Zhang DS, Nguyen HT, Choi DW, Fenton RD, Close TJ, McGuire PE, Qualset CO, Gill BS (2004) A chromosome bin map of 16, 000 expressed sequence tag loci and distribution of genes among the three genomes of polyploid wheat. Genetics 168:701–712CrossRefPubMedGoogle Scholar
- Zhang XY, Clarenz O, Cokus S, Bernatavichute YV, Pellegrini M, Goodrich J, Jacobsen SE (2007) Whole-genome analysis of histone H3 lysine 27 trimethylation in Arabidopsis. PLoS Biol 5:1026–1035Google Scholar