Long-range organization of plant satellite repeats investigated using strand-specific FISH.
The technique of chromosomal orientation and direction fluorescence in situ hybridization (COD-FISH) was adapted for plant chromosomes in order to study long-range organization of two families of satellite repeats, VicTR-B of Vicia sativa and PisTR-B of Pisum sativum. The technique allowed FISH to be performed on mitotic chromosomes in a strand-specific manner, resulting in visualization of the repeat orientation along the chromosomes and with respect to the direction of telomeric repeats. The VicTR-B probe applied to V. sativa chromosomes produced signals on a single chromatid at most regions containing corresponding sequences, thus confirming a presence of long arrays of head-to-tail arranged repeat monomers which is typical for satellite DNA. However, hybridization signals of different or equal intensities on both chromatids were also detected at some loci, suggesting a more complex arrangement of the repeats. Similar observations were made for PisTR-B repeats on P. sativum chromosomes, although the proportion of loci displaying signals on both chromatids was lower. In contrast to VicTR-B, orientation of the PisTR-B clusters with respect to telomeric sequences appeared to be conserved among subtelomeric regions of metacentric chromosomes and of the short arms of acrocentric chromosomes.
Navrátilová
A
A
Institute of Plant Molecular Biology, Laboratory of Molecular Cytogenetics, Ceské Budejovice, Czech Republic.
Neumann
P
P
Macas
J
J
D001483:Base Sequence; D032461:Chromosomes, Plant / Q000235:genetics* / Q000648:ultrastructure*; D003001:Cloning, Molecular; D017931:DNA Primers; D017404:In Situ Hybridization, Fluorescence; D018519:Meristem / Q000235:genetics; D018532:Pisum sativum / Q000235:genetics*; D036226:Seedlings / Q000235:genetics
D017931:DNA Primers