The main difference between reciprocal and nonreciprocal translocation is that reciprocal translocation is a two-way translocation responsible for the exchange of chromosomal segments between two nonhomologous chromosomes, whereas nonreciprocal translocation is a one-way translocation responsible for the movement of a chromosomal segment from one nonhomologous chromosome to another. Furthermore, two chromosomal segments take part in the reciprocal translocation, while only one chromosomal segment takes part in the nonreciprocal translocation.
In brief, reciprocal and nonreciprocal translocation are two types of interchromosomal translocation in which chromosomal segments move from one locus of the genome to another. Moreover, both types of structural rearrangements bring massive changes to the genome, causing chromosomal mutations.
Key Areas Covered
1. What is a Reciprocal Translocation
– Definition, Type of Rearrangement, Effect
2. What is a Nonreciprocal Translocation
– Definition, Type of Rearrangement, Effect
3. What are the Similarities Between Reciprocal and Nonreciprocal Translocation
– Outline of Common Features
4. What is the Difference Between Reciprocal and Nonreciprocal Translocation
– Comparison of Key Differences
Key Terms
Chromosomal Translocation, Nonreciprocal Translocation, Reciprocal Translocation, Translocation
What is a Reciprocal Translocation
Reciprocal translocation is a type of chromosomal translocation that results from the exchange of two chromosomal segments between nonhomologous chromosomes. Hence, it is a type of interchromosomal translocation, which is two-way. In general, reciprocal translocations occur in about 1 in 500 to 1 in 625 human newborns. Such translocations are harmless and can be identified through prenatal diagnosis. Furthermore, carriers have balanced reciprocal translocations, which in turn increase the risk of creating gametes with unbalanced chromosomal translocations, leading to infertility, miscarriage, and abnormalities in babies. Therefore, genetic counselling and genetic testing are important in identifying families that carry reciprocal translocations.
Figure 1: Reciprocal Translocation
Furthermore, reciprocal translocations in gametes occur due to errors in meiosis, resulting in chromosomal abnormalities in the offspring. However, reciprocal translocations can also occur in somatic cells due to errors in mitosis. And, they result in abnormalities in the affected cell lines such as chronic myelogenous leukemia with Philadelphia chromosome translocation.
What is a Nonreciprocal Translocation
Nonreciprocal translocation is a type of chromosomal translocation that results from the movement of a segment of a chromosome from one location of a nonhomologous chromosome to another. Therefore, it is a one-way transfer of genes from one locus of the genome to another.
Figure 2: Reciprocal and Nonreciprocal Translocation
Furthermore, nonreciprocal translocations result in telomere instability. Consequently, telomere dysfunctions result in the impaired regenerative capacity of hepatocytes and an increased cirrhosis formation. In addition, nonreciprocal translocation can result in neuroblastoma and several cancer types due to increased cell proliferation.
Similarities Between Reciprocal and Nonreciprocal Translocation
- Reciprocal and nonreciprocal translocation are two types of interchromosomal translocations responsible for the transfer of segments of chromosomes from one nonhomologous chromosome to another.
- They bring massive rearrangements to the structure of chromosomes.
- They are involved in the movement of chromosomal segments from one locus in the genome to another.
- Furthermore, both bring structural changes to the chromosomes by altering the size of the chromosomes and their positions of the centromere.
- They may lead to loss of function or gain of function of genes.
- Moreover, they result in chromosomal abnormalities, including leukaemia, cancer, and even infertility.
Difference Between Reciprocal and Nonreciprocal Translocation
Definition
Reciprocal translocation refers to a type of chromosome rearrangement involving the exchange of chromosome segments between two chromosomes, which do not belong to the same pair of chromosomes. In contrast, nonreciprocal translocation refers to a type of chromosomal rearrangement in which a particular chromosomal segment undergoes one-way transfer from one nonhomologous chromosome to another.
Number of Chromosomal Segments Take Part in the Process
Two chromosomal segments take part in the reciprocal translocation, while only one chromosomal segment takes part in the nonreciprocal translocation.
Type of Rearrangement
In reciprocal translocation, two chromosomal segments exchange between two loci of nonhomologous chromosomes. But, in the nonreciprocal translocation, one chromosomal segment moves one to another locus of a nonhomologous chromosome.
Effect
Moreover, reciprocal translocation results in infertility, miscarriages or children with abnormalities. But, nonreciprocal translocation results in increased cell proliferation, neuroblastoma, and especially lung cancers.
Conclusion
In brief, reciprocal translocation is a type of translocation inc which two chromosomal segments exchange between nonhomologous chromosomes. It leads to infertility and abnormalities in children. In contrast, nonreciprocal translocation is a type of translocation in which a segment of a chromosome moves into a different locus of a nonhomologous chromosome. It mainly results in cancer. Hence, the main difference between reciprocal and nonreciprocal translocation is the type of rearrangement and their effect.
References:
1. “Chromosomal Translocation.” Wikipedia, Wikimedia Foundation, 8 Dec. 2019, Available Here.
2. “Nonreciprocal Translocation.” ScienceDirect Topics, Elsevier B.V. Available Here.
Image Courtesy:
1. “Translocation-4-20” By Courtesy: National Human Genome Research Institute (Public Domain) via Commons Wikimedia
2. “Schematic illustration of chromosomal aberrations” By Philippe Hupé(CC BY-SA 3.0) via Commons Wikimedia
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