In situ DNA sequence mapping with surface-spread mouse pachytene chromosomes.
Surface-spread pachytene chromosomes are several times the length of metaphase chromosomes and the decondensed chromatin loops are attached to a well-defined axis (Weith and Traut, 1980). This arrangement permits detailed DNA sequence localization by in situ hybridization. We show that two probes to low-frequency repeated sequences (20 to 50 copies) which locate the centromere proximal in the mouse X metaphase chromosome between bands A1 and A3 (Disteche et al., 1985) and which map 5.5 cM apart (Disteche et al., 1989), hybridize to two distinct chromatin regions 3 to 5 microns apart on a 25 microns long pachytene X chromosome core.
Department of Biology, York University, Downsview, Ontario, Canada.
P B
PB
Moens
R E
RE
Pearlman
D000818:Animals; D002874:Chromosome Mapping / Q000379:methods*; D015342:DNA Probes; D008540:Meiosis; D051379:Mice; D009693:Nucleic Acid Hybridization; D012091:Repetitive Sequences, Nucleic Acid; D014960:X Chromosome / Q000648:ultrastructure
D015342:DNA Probes