Question

What does the germline configuration of the TCR variable region genes look like in all cells except mature T-cells?

a) Rearranged
b) Unrearranged
c) Hypermutated
d) Duplicated

Answer 1

The germline configuration of the TCR variable region genes in all cells except mature T-cells is unrearranged.An enzyme called DNA recombinase randomly excises most of these segments out of the gene, but in all other cells, these segments remain untouched and unrearranged.

Step-by-step explanation:

The germline configuration of the TCR variable region genes in all cells except mature T-cells is unrearranged.

During the maturation of T-cells, genetic rearrangement occurs, resulting in the rearrangement of V, D, and J segments of the TCR variable region genes.

However, in all other cells, these genes remain in their original, unrearranged state.

For example, in germ-line B cells, the variable region of the light chain gene has multiple V and J segments.

An enzyme called DNA recombinase randomly excises most of these segments out of the gene, but in all other cells, these segments remain untouched and unrearranged.