Ivan Balazs

Isolation and subregional mapping of a human cDNA clone detecting a common RELP on chromosome 12

SummarycDNA libraries are a potential source of DNA probes which can be used to screen for restriction fragment length polymorphisms (RFLPs). This approach had not been exploited until recently; in this and another paper (Balazs et al. 1984) we show that they can be a fruitful source for such probes. As an example herein we describe a common EcoRI polymorphism, detected by a randomly selected cDNA probe of unknown function. This sequence has been mapped to human chromosome 12, band q21, through the combined use of somatic cell genetics, DNA recombinant technology, and in situ hybridization.

Hybridization properties of human X-chromosomal RNA transcripts from murine-human hybrids

A human-mouse hybrid cell line which has retained the human X chromosome and a fragment of chromosome 2 contains RNA sequences transcribed from human DNA. Nuclear RNA enriched for human sequences was prepared from this hybrid cell line by a multistep hybridization procedure to mouse and human DNA immobilized on nitrocellulose filters. The properties of this RNA were analyzed by RNA-DNA hybridization techniques. The results indicate that we have pre pared a RNA fraction enriched for sequences homologous to repeated DNA sequences of the human X chromosome.