A balanced reciprocal translocation is an exchange of material between two nonhomologous chromosomes
, without loss or gain of material and balanced translocation carriers are usually healthy and phenotypically normal.
During discontinuous DNA synthesis of similar intermingled DNA sequences of nonhomologous chromosomes
, unpaired single-strand regions (located at the telomeric ends next to centromeres), are able to occasionally base-pair.
Individuals with reciprocal translocation (2-way exchange of material between 2 nonhomologous chromosomes
, with no net gain or loss of genetic material) are phenotypically normal unless the break-points interrupt or modify the function of a gene or genes (1).
According to random probability, we expect about five-sixths of the differences between CS-B lines and TM-1 to be due to the substituted chromosome or segment, and the remaining sixth due to remnant 3-79 genes in nonhomologous chromosomes
that was inadvertently retained during backcrossing and inbreeding.
These translocations, in which nonhomologous chromosomes
exchange DNA sections, result in the repositioning of a gene (located at the chromosome breakpoint) at a foreign locus and in (1) aberrant expression of the gene or (2) expression of a novel from of the gene product.
Similar, homologous chromosomes pair whereas dissimilar, nonhomologous chromosomes