Regulski, M., Lu, Z., Kendall, J., Donoghue, M. T., Reinders, J., Llaca, V., Deschamps, S., Smith, A., Levy, D., McCombie, W. R., Tingey, S., Rafalski, A., Hicks, J., Ware, D., Martienssen, R. (June 2013) The maize methylome influences mRNA splice sites and reveals widespread paramutation-like switches guided by small RNA. Genome Research, 23 (10). pp. 1651-1662. ISSN 10889051 (ISSN)
Abstract
The maize genome, with its large complement of transposons and repeats, is a paradigm for the study of epigenetic mechanisms such as paramutation and imprinting. Here, we present the genome-wide map of cytosine methylation for two maize inbred lines, B73 and Mo17. CG (65%) and CHG (50%) methylation (where H = A, C or T) is highest in transposons, while CHH (5%) methylation is likely guided by 24nt, but not 21nt, small interfering RNA (siRNA). Correlations with methylation patterns suggest that CG methylation in exons (8%) may deter insertion of Mutator transposon insertion, while CHG methylation at splice acceptor sites may inhibit RNA splicing. Using the methylation map as a guide, we used low coverage sequencing to show that parental methylation differences are inherited by recombinant inbred lines. However, frequent methylation switches, guided by siRNA, persist for up to 8 generations suggesting that epigenetic inheritance resembling paramutation is much more common than previously supposed. The methylation map will provide an invaluable resource for epigenetic studies in maize.
Actions (login required)
 |
Administrator's edit/view item |