The Localization of the Genes Coding for Histone H4 in Human Chromosomes
- L. C. Yu,
- P. Szabo,
- T. W. Borun*, and
- W. Prensky
This extract was created in the absence of an abstract.
Excerpt
The development of in situ hybridization (Gall and Pardue 1969; John et al. 1969) made possible the chromosomal localization of many repetitive DNA sequences (Steffensen and Wimber 1972; Pardue and Gall 1972; Hennig 1973). In the case of species which have polytene chromosomes, in situ hybridization is a powerful cytological mapping tool because even unique DNA sequences are found in up to 1000 copies per chromosomal site. In species lacking polytene chromosomes, a similar sequence will be represented by two copies in a metaphase chromosome, making its detection by present methods difficult at best. The use of 125I for labeling RNA was thought to extend the usefulness of the technique to the mapping of sites containing relatively few copies of a particular gene sequence (Wimber and Steffensen 1973). In particular 5S and 18S + 28S rRNA genes in various diploid chromosomes became amenable to mapping by RNA:DNA hybridization techniques (Steffensen...
