Theoretical and Applied Genetics

, Volume 96, Issue 6–7, pp 832–839

Cloning and characterization of a centromere-specific repetitive DNA element from Sorghum bicolor

  • J. T. Miller
  • S. A. Jackson
  • S. Nasuda
  • B. S. Gill
  • R. A. Wing
  • J. Jiang

DOI: 10.1007/s001220050809

Cite this article as:
Miller, J., Jackson, S., Nasuda, S. et al. Theor Appl Genet (1998) 96: 832. doi:10.1007/s001220050809

Abstract

 A 823-bp Sau3AI fragment (pSau3A10) was subcloned from a sorghum bacterial artificial chromosome (BAC) clone, 13I16, that contains DNA sequences specific to the centromeres of grass species. Sequence analysis showed that pSau3A10 consists of six copies of an approximately 137-bp monomer. The six monomers were organized into three dimers. The monomers within the dimers shared 62–72% homology and the dimers were 79–82% homologous with each other. Fluorescence in situ hybridization (FISH) analysis indicated that the Sau3A10 family is present only in the centromeres of sorghum chromosomes. Sequencing, Southern hybridization, and Fiber-FISH analyses indicated that the Sau3A10 family is tandemly arranged and is present in uninterrupted stretches of up to at least 81 kb of DNA. Slot-blot analysis estimated that the Sau3A10 family constitutes 1.6–1.9% of the sorghum genome. The long stretches of Sau3A10 sequences were interrupted by other centromeric DNA elements. Southern analysis indicated that the Sau3A10 sequence is one of the most abundant DNA families located in sorghum centromeres and is conserved only in closely related sorghum species. Methylation experiments indicated that the cytosine of the CG sites in sorghum centromeric regions is generally methylated. The structure and organization of the Sau3A10 family shared similarities with centromeric DNA repeats in other eukaryotic species. It is suggested that the Sau3A10 family is probably an important part of sorghum centromeres.

Key words Sorghum bicolor Repetitive DNA sequences Centromeres Molecular cytogenetics 

Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • J. T. Miller
    • 1
  • S. A. Jackson
    • 1
  • S. Nasuda
    • 2
  • B. S. Gill
    • 2
  • R. A. Wing
    • 3
  • J. Jiang
    • 1
  1. 1.Department of Horticulture, University of Wisconsin-Madison, Madison, WI 53706, USAUS
  2. 2.Department of Plant Pathology, Kansas State University Manhattan, KS 66506, USAUS
  3. 3.Department of Agronomy and Biological Sciences, Clemson University, Clemson, SC 29634, USAUS

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