Term
| Gene rearrangement in what region of TCRs is responsible for mammals' ability to produce such a huge variety of B & T cell receptors? |
|
Definition
|
|
Term
| What are the immunoglobulin (BCR) gene clusters found in mammals, and what chain does each code for? |
|
Definition
IGK cluster codes κ light chain
IGL cluster codes λ light chain
IGH cluster codes the heavy chain |
|
|
Term
| How many C genes code the C-region (constant region) of light chains? |
|
Definition
|
|
Term
| How many C genes code the immnoglobulin isotype of heavy chains? |
|
Definition
|
|
Term
True or False
V, D and G genes code the V-region (variable region) of light chains |
|
Definition
|
|
Term
| When & where do developing B-cells undergo gene rearrangements to increase receptor diversity? |
|
Definition
| early in development in primary lymphoid tissues |
|
|
Term
| What recombinases 'loop out' unneeded DNA from V region genes? |
|
Definition
|
|
Term
True or False
RAG 1 & 2 genes have been conserved throughout evolution |
|
Definition
|
|
Term
| What are the steps of heavy chain recombination? (5) |
|
Definition
1. Random D-J joining
2. Random V-DJ joining
3. Transcription
4. VDJ joining to C gene
5. Translation |
|
|
Term
| What is allelic exclusion? |
|
Definition
| silencing of one copy of a heavy chain gene so that only one undergoes recombination |
|
|
Term
| What occurs first, recombination of heavy chains or light chains? |
|
Definition
|
|
Term
| What are the steps of light chain recombination? (4) |
|
Definition
1. Random V-J joining
2. Transcription
3. VJ joining to C gene
4. Translation |
|
|
Term
| What light chain rearrangement is attempted first, κ or λ? |
|
Definition
|
|
Term
| What happens if the first κ light chain recombination is not successful? |
|
Definition
| Will first attempt with the other copy of κ, and then with the λ gene if necessary |
|
|
Term
| What happens if none of the light chain recombinations are successful? |
|
Definition
| B cell undergoes apoptosis |
|
|
Term
| ____ preferentially use λ light chains while _____ preferentially use κ light chains |
|
Definition
|
|
Term
| What enzymes carry out base deletions during BCR recombination? |
|
Definition
|
|
Term
| What enzyme can insert N-nucleotides or P-nucleotides into the splice site during BCR recombination? |
|
Definition
| deoxynucleotidyl-transferase (TdT) |
|
|
Term
True or False
B-cells can continue to undergo rearrangements of V-genes even after being exposed to antigens |
|
Definition
|
|
Term
| What regions of the binding site on BCRs are able to increase their binding affinity over time? What enzyme causes these random mutations? |
|
Definition
CRD1 and CRD2
cytidine deaminase |
|
|
Term
| During somatic mutations, cytidine deaminase converts ____ to ____. As a result, ______ recognizes these bases as errors or replaces them with ____ |
|
Definition
cytosines to uracil
DNA polymerase
thymine |
|
|
Term
| Why does IgM binding affinity never increase over time? |
|
Definition
| random somatic mutations doesn't occur until after class switching from IgM to IgG/IgA/IgE |
|
|
Term
| Species with very few V genes are able to increase Ig receptor diversity through.... |
|
Definition
|
|
Term
| During gene conversion, ______ converts cytosines to _____ which are replaced by _______ from pseudogenes |
|
Definition
cytidine deaminase
uracil
nucleotide insertions |
|
|
Term
| How do cattle create diversity in their light chains? |
|
Definition
|
|
Term
| How do cattle create diversity in their heavy chains? |
|
Definition
|
|
Term
True or False
Chickens have a large number of functional V genes |
|
Definition
|
|
Term
| How do chickens create immunoglobulin diversity? |
|
Definition
| gene conversion, some somatic mutation |
|
|
Term
True or False
Truncated avian IgY has a high affinity for binding to Fc receptors |
|
Definition
|
|
Term
| Avian IgY has ____ heavy and ___ light chains and is lacking a ___ |
|
Definition
|
|
Term
True or False
Fish do not have deoxynucleotidyl transferase and as such are not able to carry out nucleotide insertions during recombination |
|
Definition
|
|
Term
True or False
Fish have a poor secondary immune response |
|
Definition
|
|
Term
| How do cartilaginous fish BCR/TCR genes differ from mammals & bony fish? |
|
Definition
| VDJC fences are arranged in that order in a repeating pattern |
|
|
Term
True or False
Cartilaginous fish have Ig light chains, but these do not appear to be homologues to the human versions |
|
Definition
|
|
Term
| What are the TCR gene clusters found in mammals, and what chain does each code for? |
|
Definition
TRB contains VDJC genes for beta chain
TRA/D contains VJC genes for alpha chain, and VDJC for δ chain
TRG cluster contains VJC genes for γ chain |
|
|
Term
| How is TCR diversity generated? |
|
Definition
gene recombination
combinatorial association |
|
|
Term
| What is combinatorial association? |
|
Definition
combination of different α and β
chains, and γ and δ chains
OR between different Ig heavy & light chains |
|
|
Term
| What TCR gene cluster undergoes rearrangement first, and where does this occur? |
|
Definition
|
|
Term
| What happens if TRG rearrangement is unsuccessful in creating a functional γδ TCR? |
|
Definition
TRB & TRA rearrangement will be attempted
-if successful, TRD cluster is deleted |
|
|
Term
| Mice and humans have a ___ combinational repertoire in the TRD and TRG clusters |
|
Definition
|
|
Term
| Which is more diverse in TRD & TRG clusters, ruminants or mice? |
|
Definition
|
|
Term
| Ruminants are able to carry out combinatorial association between single ____ chain and several ____ chains |
|
Definition
|
|
Term
| How many IGHJ germline genes to pigs have? |
|
Definition
|
|
Term
| What is the first stage of developing antigen receptor diversity in piglets? |
|
Definition
| Recombination of VDJ genes, migration of B cells to GALT & subsequent proliferation |
|
|
Term
| Where does the second stage of developing antigen receptor diversity in piglets occur? |
|
Definition
| in intestinal lymphoid organs which are in direct contact with intestinal microflora |
|
|
