Gene Mapping
There are 3 different types of genes:
- A regulator gene. That is a gene that causes the production of a protein that regulates or suppresses the activity of one or more structural genes.
- A structural gene. That is a gene that determines the amino acid sequence of a protein.
- An operator gene activates the production of messenger RNA by adjacent structural genes.
Regulator genes are located in the 98% of the DNA that is non-coding. They influence the behavior of the Structural genes, found in the 2% DNA used by the cells in our body.
A Gene is a section of the DNA that encodes instructions that allow a cell to produce a specific molecule- a protein such as an enzyme – that initiates one specific action.
A gene can have several 100.000s of base-Twins. Genes are responsible for physical traits in the organism, such as eye color or blood type. Understanding genes allows scientists to understand physical traits in living creatures.
The latest research findings suggest between 20,000 and 30,000 human protein-coding genes. Human cells make extensive use of alternative splicing to produce different proteins from a single gene.
Structural Gene mapping
Gene mapping refers to one of two different ways of locating the gene on a chromosome:
- Genetic mapping refers to the use of linkage analysis to determine how two genes on a chromosome relate in their positions. It is obtaining an ordered list of genes on a strand of DNA, like listing each exit on a highway.
- Physical mapping locates genes by their absolute positions on a chromosome using any technique, like marking landmarks around each highway exit. Once a gene is located, it can be cloned, its DNA sequence determined, and its molecular product studied.
The diagram shows a gene in relation to the double helix DNA and an X-shaped (dividing) chromosome. Introns are regions that are removed after the DNA is transcribed into RNA. Only the exons encode the protein. A gene-region is usually 100\’s times larger than the diagram shows.
