Explain the molecular mechanism of isotype switching
What will be an ideal response?
The molecular mechanism involves a recombination between sequences, called switch regions, which lie upstream (on the 5? side) of heavy-chain C genes. All heavy-chain C genes except C? have a switch region. Recombination between two switch regions results in the excision of DNA (as a circular DNA molecule) between the two and the movement of the new heavy-chain C gene next to the preserved V region. Transcription will produce an mRNA encoding the same V-region sequence and the new C region. Switching can occur between the first switch region and any other switch region that lies downstream (on the 3? side). Isotype switching is not random but is influenced by T-cell cytokines.
You might also like to view...
Juvenile papillomatosis was diagnosed in the larynx of a two-year-old child. This lesion is caused by
A. herpes simplex virus B. human papilloma virus (HPV) C. hepadna virus D. adenovirus E. parvovirus
This procedure involves the use of sandpaper-like abrasives for the removal of unwanted scars or tattoos
A) rhytidectomy B) liposuction C) debridement D) dermabrasion
Animal proteins are usually a good source of ________ proteins, which are composed of ample amounts of essential amino acids.
Fill in the blank(s) with the appropriate word(s).
In which of the following cases did the court find that the pharmacist could be held liable for failing to warn a customer that he should not take the prescribed medication with alcohol?
A. Ingram v. Hooks B. Hand v. Krakowski C. Riff v. Morgan D. Dooley v. Everett