Transposon || Transposon In Human & Transposon in Bacteria

 Transposon






  Transposon Are the group of mobile genetic  element that are  define as a  DNA sequence . Trans. Can jump into  different places of the genome for this reason they are called jumping gene. They are divided in to two main groups-

 i) Retro transposon    ii)  DNA transposon


Trasposon in bacteria: 

There are two main types of transposable elements in bacteria having  diff siz and structure.

 1. Insertion sequence (IS) elements.

2. Prokaryotic transposon Tn - composite and non composite transposons.

1. . Insertion sequence (IS)- 




2. Prokaryotic transposon - 




Transposon in human

Transposon in human are in the form of repetitive  DNA which consists of sequence that are interspersed  within the entire human genome. This sequence are  transposable and can move to diff location within the genome . These are of two types- 1. SINE ( short interspersed elements) 2. LINE( long interspersed elements)

1.SINE ( short interspersed elements)- These are  about 300 bp long and may be present about 5 lakh times in human genome. Ex Alu sequence are the best characterized SINEs in human.

  These are termed as Alu elements because they  contain specific nucleotides sequence which are cleave by the restriction enzyme named Alu1 .Alu elements contains direct terminal repeats DTR of 7 to 20 bp length. This dtr help them in the insertion process during transposition.

2.LINE -(long interspersed elements):  They are about 6499 bp long and  present about 1llakh time in the human genome . Most prominent ex. Is L1 sequence. This transposible elements are some of the most  abundant & common families of moderately repeated sequences in human DNA.


SIGNIFICANT IF TRANSPOSABLE ELEMENTS:

1. Trans may changed the structural snd functional characteristics if genome by changing their position in the genome. 

2. They may caused mutation. Insertion. Deletions etc. 

3. Transposon a make positive contribution in the evolution as they have  tremendous impacts in the alternation if genetic organization if organism. 4. They are useful as cloning vectors in gene cloning and may also be used as genetic markers during genome maping.

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