Question

• RAG is recombination activating gene
• 1) Identify the technique that could be used to demonstrate the function of RAG
• 2)Hypothesize what would occur in a patient born without functional RAG
• 3) Identify the enzyme that randomly adds nucleotides to the chromosome during VDJ recombination
• 4) Identify the five mechanisms to generate antibody diversity

Answer 1

1) mouse with wild type RAG or knocked out with RAG can be transfected with plasmids envoding suitable V(D) J substrate plasmids with terminator sequence that are flanked by recombination signal sequences (RSS) and the plasmid has GFP gene followed by terminator sequence. If RAG works fine it cleaves the terminator sequence and GFP will be expressed . In RAG knocked out mouse the GDP will not express

2. T lymphocytes or B lynphocytes with receptor recombination is important for adaptive immunity. If RAG gene not active the patients will deveolope sever combined immunodeficiency and omenn syndrome. If RAG is not active the person cannot fight against diseases and infections

3) terminal deoxynuclotidal transferase is the enzyme that adds nuclotides without nucleotides in V(D) J recombination

4. Mechanisms to generate antibody diversity

Somatic hypermutation

Combination of V( D) J joining

Random assortment of heavy and light chains

Multigene organization of immunoglobulin genes

Junctional flexibility

N region addition of nucleotides that are not encoded in the germline

P region additions of nucleotides that are not encoded in the germline