Characterization and mapping of DNA sequence homologous to mouse U1a1 snRNA: localization on chromosome 11 near the Dlb-1 and Re loci.

A phage clone which contained a functional U1a1 snRNA gene was isolated from a mouse genomic library. A single copy fragment was isolated from the 3' flanking region of the U1a1 gene and used as a hybridization probe for Southern blotted DNAs from recombinant inbred strains of mice, mouse-hamster hybrid cells, and the offspring from backcrosses between BALB/c mice and mice which were heterozygous for the Rex (Re) marker. The results of these experiments prove that the U1a1 gene is located on chromosome 11 near the Delb-1 and Re loci.