Differential action of restriction endonucleases on chromosomes prepared for light and electron microscopy

Abstract

Whole mounted chromosomes from the L929 mouse cell line were digested on grids with HinfI and AluI restriction endonucleases and studied by electron microscopy. Results show differences in the pattern of bands obtained in a marker chromosome when compared with those previously reported by light microscopy with the same restriction endonucleases. These differences suggest that the accessibility of restriction sites on chromosomes may be modulated by preparatory methods for chromosome analysis.

Restriction enzymes induced bands in the cave cricketDolichopoda schiavazzii(Orthoptera, Rhaphidophoridae): Implications for heterochromatin characterization and satellite DNA distribution

“…Recent studies have pointed out that a number of factors may deeply influence the action of RE on chromatin in toto, so that a direct correlation between the obtained banding patterns and the distribution of the target sequences could not always be detected (Gosalvez et al, 1990). In spite of this, in many cases molecular data and the results obtained by the RE in situ have shown a high degree of correlation, particularly when the presence and localization of highly repeated DNAs are considered (Bianchi et al, 1985;De Stefano et al, 1985;Ferrucci et al, 1987).…”