What are marker genes? Write examples.

Hint: It is a genetic marker that is present in the DNA sequence with a known physical location on a chromosome. They are used to link inherited disease with the gene that is responsible. They are mainly the part of the gene whose role is nil in the chromosome.

Complete answer:
A marker gene is known as a DNA sequence that is located near the target gene with detachable and all the inherited properties. It is an application in genetic engineering experiments, mainly in genetic research in plants. Structurally, the marker gene is known as DNA nearer to a gene that is used to locate the target gene. They are of two types: selectable marker gene and receptor gene.

The antibiotic-resistant gene which is a type of selectable marker gene is one of the examples of the marker gene that is used in genetic transformation experiments. The techniques of genetic engineering are used to alter the genome of the target organism to get the desired phenotype.
By using marker gene sequence, we can distinguish non- altered cell population and layered cell population.

Properties of marker gene:
- To select some gene as a marker gene that should have many unique properties in it.
- It must be located near the target gene.
- It is inherited with the target gene.
- It should be located on the same chromosome as the target gene.
- It is amplified and can be detected very quickly.

Note: Selectable marker gene is used to make genetically modified organisms. Their main function is to use these markers to achieve a subsidiary secondary function along with the target gene. The screen-able markers are gene sequences that are used to screen cell populations which is altered or not. These altered cells that contain screenable markers give a signal that the target is inserted correctly.