An animal heterozygous for a reciprocal balanced translocation has the following chromosomes:
           MN • OPQRST
           MN • OPQRjkl
           cdef • ghijkl
           cdef • ghiST

Identify the gametes produced by adjacent-1 segregation. Which if any of these gametes are viable?

Key Concepts

Reciprocal Balanced Translocation

A reciprocal balanced translocation occurs when two chromosomes exchange segments without any loss of genetic material. This results in a rearrangement of genes but maintains the overall genetic balance. In organisms with such translocations, the chromosomes can pair during meiosis, leading to unique segregation patterns that can affect gamete viability.

Adjacent-1 Segregation

Adjacent-1 segregation is a specific way chromosomes can segregate during meiosis in individuals with reciprocal translocations. In this process, one chromosome from each pair of homologous chromosomes is selected, leading to gametes that contain both segments from the translocated chromosomes. This type of segregation often results in gametes that are unbalanced, which can affect their viability.

Gamete Viability

Gamete viability refers to the ability of gametes to develop into a viable organism after fertilization. In the context of adjacent-1 segregation, the resulting gametes may have an unbalanced genetic composition, which can lead to non-viable embryos or developmental issues. Understanding which gametes are viable is crucial for predicting the outcomes of genetic crosses involving translocations.