1. DNA Marker Lecture 10 BY Ms. Shumaila Azam
Genomics
DNA Marker
Lecture 10
BY Ms. Shumaila Azam

2. DNA Markers
A genetic marker is a gene or DNA sequence with a known location on a chromosome that can be used to identify individuals or species.
It can be described as a variation that can be observed.
Which may arise due to mutation or alteration in the genomic loci.

3. Types Some commonly used types of genetic markers are
RFLP (or Restriction fragment length polymorphism)
RFLP was an important tool in genome mapping, localization of genes for genetic disorders, determination of risk for disease, and paternity testing.
SSLP (or Simple sequence length polymorphism)
can be used to understand genetic variance between two individuals in a certain species
AFLP (or Amplified fragment length polymorphism)
AFLP has become widely used for the identification of genetic variation in strains or closely related species of plants, fungi, animals, and bacteria.

4. Types RAPD (or Random amplification of polymorphic DNA)
RAPD has been used to characterize, and trace, the phylogeny of diverse plant and animal species.
VNTR (or Variable number tandem repeat)
Their analysis is useful in genetics and biology research, forensics, and DNA fingerprinting.
SSR Microsatellite polymorphism, (or Simple sequence repeat)
They can also be used for studies of gene duplication or deletion, marker assisted selection, and fingerprinting.

5. Types SNP (or Single nucleotide polymorphism)
SNPs are also critical for personalized medicine.
STR (or Short tandem repeat)
Their analysis is useful in genetics and biology research, forensics, and DNA fingerprinting.

6. Categories of markers
Biochemical markers which detect variation at the gene product level such as changes in proteins and amino acids
Molecular markers which detect variation at the DNA level such as nucleotide changes: deletion, duplication, inversion and/or insertion.

7. Mode of inheritance Dominance/recessive Co-dominance
If the genetic pattern of homozygotes can be distinguished from that of heterozygotes, then a marker is said to be co-dominant.
Co-dominant markers are more informative than the dominant markers.

8. Uses of Markers
Genetic markers can be used to study the relationship between an inherited disease and its genetic cause
Genetic markers are employed in genealogical DNA testing for genetic genealogy to determine genetic distance between individuals or populations.
With the aid of genetic markers, researchers were able to provide conclusive evidence that the cancerous tumor cell evolved into a transmissible parasite.
molecular genetic markers were used to resolve the issue of natural transmission, the breed of origin (phylogenetics), and the age of the canine tumor.
Genetic markers have also been used to measure the genomic response to selection in livestock.