This document summarizes information about transposons. It discusses that Barbara McClintock discovered transposons in maize in 1948 and was awarded a Nobel Prize for this discovery in 1983. It describes transposons as sequences of DNA that can move to different locations within a genome. The document outlines different types of transposons, including Class 1 and Class 2, and their mechanisms of transposition. It also discusses transposons' involvement in disease.

2. ALI RAZA
BS ZOLOGY 5th SEMESTER
ROLL #4029

3. Presented To
• Mr. Danish Riaz
• Lecturer of Zoology
• Govt. Postgraduate
College ,
Samanabad
Faisalabad

5. INTRODUCTION
• transposon, A sequence of DNA that “jump”
to different locations within a genome.
Although these elements are frequently called
“jumping genes,” they are always maintained
in an integrated site in the genome. In
addition, most transposons eventually
become inactive and no longer move.

6. Contents
Introduction
Discovery of Transposons
Characteristics of Transposons
Types of Transposons
 Mechanism of transposition
Transposons and disease

8. Discovery
Barbara McClintock discovered the first TEs in
maize, Zea mays in 1948.
She was awarded a Nobel Prize in Medicine or
Physiology in 1983 for her discovery of TE.
She noticed insertions, deletions, and
translocations, caused by these elements. These
changes in the genome could, for example, lead to a
change in the colour of corn kernels. About 85% of
the genome of maize consists in Tes.

9. 1. Nbarobelprize.org
BARARRADADDADAADDAFCCACFCCC
AFFAFFAFFF
KA
(1983 Nobel Prize in Physiology and
Medicine)
2. profiles.nlm.nih.gov/LL/
Barbara McClintock 1902-1992
Corn (maize) varieties

15. CLASS 2 ( Sim ple TN)

THESE
CONSIST OF
THAT
MOVES
DIRECTLY
FROM ONE
PLACE
ANOTHER.
CLASS 1 ( Retrotran
sposon TN
These are
retrotransposons that
first the DNA
Into RNA and then
Use reverse
transcriptase to make
a DNA copy of the RNA
to insert in a new
location

16. Transposition Pathways

17. Simple & Replicative Transposons

18.  Known as Insertion Sequences - IS
 bacterial
 Tn10
 eukaryotic
 Ac/Ds
Simple Transposition

20.  Direct repeats – DNA sequences that are identical and
run in the same direction (5’3’)
 Inverted repeats - DNA sequences that are identical (or very
similar) but run in opposite directions
5’ CTGACTCTT 3’
3’ GACTGAGAA 5’
5’ AAGAGTCAG 3’
3’ TTCTCAGTC 5’and
Regulatory Sequences of Transposable Elements
5’ ATGACTGAC 3’
3’ TACTGACTG 5’
5’ ATGACTGAC 3’
3’ TACTGACTG 5’
and
transposon

21. 1) Involves replication of the TE and insertion of the copy
into another chromosomal location
2) Only found in bacteria
Replicative Transposition

23. 1) Very common but only occurs in eukaryotes
2) These types of elements are termed
retroelements or retrotransposons
3) Similar organization to retroviruses
Retrotranposons & Retrotransposition

24. Transposase Catalyzes Excision & Insertion

25. 17-67
They are in the same
direction and are repeated
at both ends of the
element

27. TRANSPOSON and disease
1) They cause resistance against antibiotic.
2) They referred as ‘‘Selfish DNA’’.
3) They cause mutation.
4) Give rise to cancer.
5) A gap are formed in the gene after DNA
6) transposon.