The key difference between genetic map and linkage map is the type of genes used for the mapping process. Genetic map consists of all genes present on a particular chromosome while linkage map consists of linked genes present on a particular chromosome.
Genetic map and linkage map are two types of chromosomal maps that illustrate genes found on the chromosomes. A genetic map shows all the genes while a linkage map shows only the linked genes. Both are very useful in diagnosing genetic diseases and disorders. In addition, chromosomal aberrations can also be detected using genetic and linkage maps. Linkage maps further provide an idea of the evolution of particular genes.
CONTENTS
1. Overview and Key Difference
2. What is Genetic Map
3. What is Linkage Map
4. Similarities Between Genetic Map and Linkage Map
5. Side by Side Comparison – Genetic Map vs Linkage Map in Tabular Form
6. Summary
What is a Genetic Map?
Genetic map is the complete map of genes in a chromosome. This is also known as chromosome mapping. This will provide information on the specific genes located in the chromosome. Moreover, the genetic mapping process utilizes physical mapping method to locate genes on the chromosomes.
Figure 01: Genetic Map
Genetic mapping can also find chromosomal aberrations. Therefore, the genetic map acts as a diagnostic tool to detect conditions such as Downs syndrome and Turners syndrome. Karyotyping is one technique that can be used to generate a genetic map. Furthermore, staining is an important technique to generate a genetic map. Different types of stains such as ethidium bromide, acridine orange and Giemsa are utilized in staining.
What is a Linkage Map?
The linkage gene map utilizes the concept of genetic linkage. Therefore, a linkage map shows the linked gens present on a chromosome. This is often misinterpreted as a genetic map as well. Mapping of the linked genes determining the physical characteristics is important in genetic diagnostics. This also provides an idea about the inheritance of genes located very close to each other in a chromosome.
Figure 02: Linkage Map
Linkage mapping also makes the researcher understand how genes exist precisely in a chromosome. It is also important in diagnosing diseases.
What are the Similarities Between Genetic Map and Linkage Map?
- Genetic map and linkage maps are important in the diagnosis of chromosomal aberrations and genetic diseases.
- Both use staining techniques to visualize genes under microscopy.
- Moreover, karyotyping is the method we use in both mapping techniques.
What is the Difference Between Genetic Map and Linkage Map?
A genetic map shows the complete set of genes present on a chromosome. In contrast, a linkage map shows only the linked genes present on a chromosome. So, this is the key difference between genetic map and linkage map. Genetic maps are mainly important in diagnosing diseases and detecting chromosomal aberrations while linkage maps are mainly useful in understanding inheritance and evolution of linked genes and related genetic disorders. This is the difference between genetic map and linkage map in terms of usage.
Summary – Genetic Map vs Linkage Map
Genetic mapping and linkage mapping are two mapping techniques used in genetic diagnosis. DNA is the source for both types of mapping. The genetic map illustrates all the genes in a particular chromosome while the linkage map shows the linked genes in a particular chromosome. This is the key difference between genetic map and linkage map. Karyotyping is the technique we use for both mapping techniques. It plays an important role in determining the evolution and genetic trends.
Reference:
1. “Genetic Linkage & Mapping.” Khan Academy, Khan Academy, Available here.
2. “Gene Map.” Gene Map – an Overview | ScienceDirect Topics, Available here.
Image Courtesy:
1. “NHGRI Fact Sheet- Genetic Mapping (27058469495)” By National Human Genome Research Institute (NHGRI) from Bethesda, MD, USA – NHGRI Fact Sheet: Genetic Mapping (CC BY 2.0) via Commons Wikimedia
2. “Drosophila Gene Linkage Map” By Twaanders17 – Own work (CC BY-SA 4.0) via Commons Wikimedia