Ultrastructural banding induced by DraI or HaeIII progressive digestion and in situ nick translation on human chromosomes.
Fixed human metaphase chromosomes were progressively digested with DraI or HaeIII restriction enzymes, submitted to in situ nick translation, and observed by transmission electron microscopy to obtain further information on the localization of the endonuclease target sequences and on the conformational changes in chromosomal bands. This approach allows us to detect specific nick translation patterns, namely, G-banding or R-like banding after short DraI and HaeIII endonuclease digestion, respectively. Intermediate banding recognizable as C-negative banding and G + C banding are induced by longer HaeIII digestion, before the C-positive banding. These patterns appear to depend both on different target sites of the employed endonucleases and on the DNA loss at different digestion times.
Del Coco
R
R
Istituto di Citomorfologia Normale e Patologica, CNR, Bologna, Italy.
Stuppia
L
L
Cinti
C
C
Peila
R
R
Maraldi
N M
NM
D002478:Cells, Cultured; D002871:Chromosome Banding / Q000379:methods*; D002875:Chromosomes / Q000648:ultrastructure*; D015252:Deoxyribonucleases, Type II Site-Specific; D006801:Humans; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000166:cytology; D008854:Microscopy, Electron
D015252:Deoxyribonucleases, Type II Site-Specific; C024403:GGCC-specific type II deoxyribonucleases; C035594:TTTAAA -specific type II deoxyribonucleases