JcSat1, a novel subtelomeric repeat of Jatropha curcas L. and its use in karyotyping

Abstract

Jatropha is considered a promising crop for the production of biodiesel; however, a standard karyotype based on fluorescent in situ hybridization (FISH) analysis has not yet been constructed. In this paper, we describe the isolation of a tandem repeat sequence, JcSat1 (Jatropha curcas satellite 1). The sequence consists of a repeat unit of 358-360 bp including a telomere repeat sequence and is located in the subtelomeric heterochromatin. The intensity of JcSat1 signal varied between loci, allowing the identification of six out of eleven pairs of Jatropha chromosomes. FISH analysis of the nuclei of meiotic cells revealed the non-Rabl distribution of JcSat1 and the telomere bouquet structure. Our results suggest that JcSat1 together with other chromosome markers, such as ribosomal DNAs, will help in the identification of each Jatropha chromosome and analysis of the chromosome dynamics during mitosis and meiosis.