Each domain consists of -40 kilobases of DNA, or may be smaller, 10 kb each. About -400 domains in the E. coli genome. The ends of the domains appear to be randomly distributed instead of located at predetermined sites on the chromosome.

TLS Online TPP Program

#Id: 7224

#Unit 5. Developmental Biology

Two distinct selection processes are required

Positive selection, which selects for those thymocytes bearing receptors capable of binding self-MHC molecules, resulting in MHC restriction

Negative selection, which selects against thymocytes bearing high-affinity receptors for self-MHC/peptide complexes, resulting in self-tolerance.

TLS Online TPP Program

#Id: 7225

#Unit 5. Developmental Biology

TLS Online TPP Program

#Id: 7226

#Unit 5. Developmental Biology

Relationship between TCR affinity and selection

TLS Online TPP Program

#Id: 7227

#Unit 5. Developmental Biology

T-cell education

TLS Online TPP Program

#Id: 7228

#Unit 5. Developmental Biology

Superantigens

Viral or bacterial proteins that bind simultaneously to the Vβ domain of a T-cell receptor and to the α chain of a Class II MHC molecule

TLS Online TPP Program

#Id: 7229

#Unit 5. Developmental Biology

Lineage commitment