PAG-V: P106 - FLUORESCENCE IN SITU HYBRIDIZATION WITH SIMPLE SEQUENCE REPEAT PROBES IN PHASEOLUS AND CICER

Plant & Animal Genome V Conference

Town & Country Hotel, San Diego, CA, January 12-16, 1997.

P106

FLUORESCENCE IN SITU HYBRIDIZATION WITH SIMPLE SEQUENCE REPEAT PROBES IN PHASEOLUS AND CICER

NENNO, MARIO(1), GOETZ GORTNER(2), Dorothea Zink(2), Kurt Weising(3), Günter Kahl(3), Walter Nagl(3)
1. Division of Cell Biology, Erwin-Schrödinger-Str., University of Kaiserslautern, D-67653 Kaiserslautern, Germany
2. Department of Biology, Biozentrum, Marie-Curie-Str.9 , University of Frankfurt, D-60439 Frankfurt am Main, Germany
3. Biozentrum, Marie-Curie-Str.9 , University of Frankfurt, D-60439 Frankfurt am Main, Germany

Fluorescence in situ hybridization (FISH) was used to examine the distribution of simple sequence repeats (SSR) or microsatellites in two legumes, Phaseolus and Cicer. Polytene chromosomes from the embryo suspensor of Phaseolus coccineus, interphase nuclei from endosperm and metaphase chromosome from root-tips of Cicer arietinum have been investigated. The probes for the simple sequence repeats were 5’-Digoxigenin endlabeled synthetic oligonucleotides. Detections were performed either with the DIG-signal amplification system or a new DIG-Biotin-hybrid detection system to increase the signal intensity of the probes. We found that all of the tested mono-, di-, tri- and tetranucleotide repeats hybridized to polytene chromosomes, interphase nuclei and metaphase chromosomes. The signal distribution of the SSRs is non-random and specific. While the (GATA)₄ element shows a similar hybridization pattern both in Phaseolus and Cicer, the (A)₁₆ element is distributed completely different. The latter is preferentially located in heterochromatic regions of Phaselus polytene chromosomes but in euchromatic regions of interphase nuclei and metaphase chromosomes of Cicer. These data, further findings and their significance for the genomic organization of SSRs in Phaseolus and Cicer will be discussed.