Centromere-specific repetitive sequences from Torenia, a model plant for interspecific fertilization, and whole-mount FISH of its interspecific hybrid embryos

Publication Type:Journal Article
Year of Publication:2005
Authors:S. Kikuchi, Kish, ii, M., Shimizu, M., Tsujimoto, H.
Journal:Cytogenet Genome Res
Date Published:Jan
Keywords:Centromere, Chromosomes: Plant, Cloning: Molecular, DNA: Plant, In Situ Hybridization: Fluorescence, Lamiaceae, Phylogeny, Repetitive Sequences: Nucleic Acid, Reproduction

Torenia fournieri is a good model plant to study fertilization in plants because it is easy to observe the fertilization process due to the protruding nature of the embryo sac. To study the location and movement of chromosomes and their centromeres in early embryogenesis of interspecific hybrid plants, we isolated two families of centromere-specific tandem repetitive sequences from T. fournieri and T. bailonii, and named them the "TCEN-family" and "BCEN-family", respectively. Both sequences consisted of a repeat unit of 52 bp located in the pericentric and centric heterochromatins. All signals of both sequences were prominent, but their intensity varied among the chromosomes. DNA-blot hybridization indicated the presence of similar sequences of TCEN-family in T. concolor, N. caerulea, and "Summer Wave", whereas the BCEN-family was found only in T. bailonii, thus indicating the wide or specific distribution of their repetitive families observed. We also applied whole-mount FISH to the interspecific hybrid embryos by using TCEN- and BCEN-family sequences as probes. Our results suggest that whole-mount FISH with the species-specific centromere sequences as probes is an ideal method to analyze the dynamics of chromosomes and centromeres in interspecific fertilization and early embryogenesis.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith