A translocation in the mouse discovered by B. M. Cattanach. The aberration involves an X chromosome into which a segment of autosome 7 has been translocated. The insertion carries the wild-type alleles of three autosomal genes that control the color of the fur. Studies on mice heterozygous for the Cattanach translocation have shown that during X-chromosome inactivation in somatic cells, the genes in the inserted autosomal segment are turned off sequentially in order of their distances from the X chromosomal element. Thus, the X inactivation spreads into the attached autosomal segment, but does not travel unabated to the end of the segment.
Subjects: Genetics and Genomics.