2. Gene of known function and location
Gene that allows studying the inheritance of that gene
Genetic information resides in the genome
Genetic Marker
Any phenotypic difference controlled by genes, that can be
used for studying recombination processes or selection of a more
or less closely associated target gene
Anything in the genome that is variable and can be used to
compare individuals
Detectable allelic variation on a chromosome can be a
phenotype, can also be a unique detectable sequence of DNA
3. Marker is a piece of DNA
molecule that is
associated with a certain
trait of a organism
Types of
Markers
Morphological
Biochemical Genetic
Chromosomal
4. Animals are selected based on
appearance
Eg. PIGMENTATION
Disadvantage: lack of polymorphism
5. Animals are selected based on biochemical
properties
Eg. Hb, AMYLASE, BLOOD GROUPS ETC.
Disadvantage:
Sex limited
Age dependent
Influenced by environment
It covers less than 10% of genome
6. Animals are selected based on
structural & numerical variations
Eg. Structural and Numerical Variations
Structural- Deletions, Insertions etc.
Numerical- Trisomy, Monosomy, Nullysomy
Disadvantage: low polymorphism
7.
8. Organism can be differentiated by analysis of patterns derived from cleavage of their
DNA.
Technique is mainly based on the special enzyme called Restriction Endonucleases.
In RFLP restriction enzyme digested DNA is resolved by gel electrophoresis and then
blotted to a nitro cellulose membrane.
Specific binding pattern can be visualized by hybridization with labeled probe.
Different size or length of restriction fragments are produced such polymorphism
are used to distinguish plant species, genotype etc.
