Complex Organization and Evolution of the Tomato Pericentromeric Region at the FER Gene Locus

Tomato (Lycopersicon esculentum) is a model species for molecular biology research and a candidate for large-scale genome sequencing. Pericentromeric heterochromatin constitutes a large portion of the tomato chromosomes. However, the knowledge of the structure, organization, and evolution of such regions remains very limited. Here, we report the analysis of a 198-kb sequence near the FER gene, located in a distal part of pericentromeric heterochromatin on the long arm of tomato chromosome 6. Nine genes, one pseudogene, and 55 transposable elements (TEs) were identified, showing a low gene density (19.8 kb/gene) and a high content of transposable elements (>45% of the sequence). Six genes (56B23_g3, g5, g7, g8, g9, and g10) have perfect matches (>98% identity) with tomato expressed sequence tags. Two genes (56B23_g1 and g6), which share