SSR and ISSR.pdf

Prepare for a genetic face-off as we unravel the intriguing world of microsatellites in our latest PDF, "SSR vs. ISSR Showdown." Dive into the microscopic realm of Simple Sequence Repeats (SSR) and Inter-Simple Sequence Repeats (ISSR), as we dissect their unique features, applications, and the genetic tales they unveil.

1. Simple
Sequence
Repeats
Microsatellite
markers
Microsatellites are tandem
stretches of mono-, di-, tri- or
tetranucleotide sequence
motifs that frequently
occur as randomly dispersed
repetitive elements in
eukaryotic genome

2. •Genetic markers resulting from variation in length of SSR loci (
tandem repeats of very short motifs ( 1-6 bp) e.g.(GT)n, (CAC)n).
•Microsatellite markers are developed by PCR amplification of genomic
DNA segments recognized by primers complementary to unique
flanking sequences(specific primers 20-25 base ).
•Primer sequence might be identified from:
➢Published sequences
➢or Screening a clone library for repeat units and sequencing the
positive clones

3. Advantages
•Highly abundant and evenly
distributed in the genome
•Highly polymorphic.
•Codominant.
•Rapidly typed and easy to
automate
Disadvantages
•Require knowledge about the
primers sequence.

4. Inter
Simple
Sequence
Repeat

5. •Genomic DNA amplified with a microsatellite complementary primer
[eg: (GACA)4 , (GT)n.. etc)].
•SSR-based primers are usually 15 mersto 20 mersenabling high
stringency amplifications than RAPD.
•Amplified products are resolvable on:
➢agarose gel using ethidium bromide staining.
➢or polyacrylamide gels by silver staining.

8. •SSR markers are microsatellite
DNA
•contain nucleotide repeats of 1-
6 nucleotides
•recognize heterozygous loci
•amplify tandem repeats
•codominant
•ISSR markers occur between
microsatellite DNA.
•contain nucleotide repeats of
100-300 nucleotides.
•recognize multiple loci.
•amplify random sequences of
the genome.
•dominant