The two main chromosome-segregation patterns in a reciprocal-translocation heterozygoteThe segregating chromosomes of a reciprocal-translocation heterozygote form a cross-shaped pairing configuration. The two most commonly encountered segregation patterns that result are the often inviable “adjacent-1” and the viable “alternate.” N1 and N2, normal nonhomologous chromosomes; T1 and T2, translocated chromosomes. Up and Down designate the opposite poles to which homologs migrate in anaphase I.