A third way that gene duplicates arise is by retrotransposition.

Here the messenger RNA from a gene is reverse-transcribed to DNA, which is then integrated into the genome.

TLS Online TPP Program

#Id: 1681

#Unit 4. Cell Communication and Cell Signaling

Non - templated N nucleotide addition in heavy chains results from TdT activity.

TLS Online TPP Program

#Id: 1682

#Unit 4. Cell Communication and Cell Signaling

Exonuclease trimming sometimes occurs at the VDJ and VJ junctions, causing loss of nucleotides.

TLS Online TPP Program

#Id: 1683

#Unit 4. Cell Communication and Cell Signaling

Combinatorial diversity: The same heavy chain can combine with different light chain

TLS Online TPP Program

#Id: 1684

#Unit 4. Cell Communication and Cell Signaling

This recombinational event is catalyzed by a set of enzymes, many of which are also involved in nonhomologous end joining (NHEJ) DNA repair functions that occur in all cells.

TLS Online TPP Program

#Id: 1685

#Unit 4. Cell Communication and Cell Signaling

Only three of the proteins implicated in V(D)J recombination are unique to lymphocytes: RAG1, RAG2, and Terminal deoxynucleotidyl Transferase (TdT)

TLS Online TPP Program

#Id: 1686

#Unit 4. Cell Communication and Cell Signaling

Recombination between the D and a JH gene segment occur during pre pro-B cell to the early pro-B-cell stage.