Expression
In germline cells, the gene segment encoding the μ constant region of the heavy chain is positioned first among other constant region gene segments. For this reason, IgM is the first immunoglobulin expressed by mature B cells.
It is also the first immunoglobulin expressed in the fetus (around 20 weeks) and also phylogenetically the earliest antibody to develop.
Read more about this topic: Immunoglobulin M
Famous quotes containing the word expression:
“You have to begin to lose your memory, if only in bits and pieces, to realize that memory is what makes our lives. Life without memory is no life at all, just as an intelligence without the possibility of expression is not really an intelligence. Our memory is our coherence, our reason, our feeling, even our action. Without it, we are nothing.”
—Luis Buñuel (1900–1983)
“An unlicked bear”
—Trans. by Johanna Prins.
Dutch expression meaning “a boor”: from the old belief that bear cubs are licked into shape by their mothers.
“A wicked mortal is not the idea of God. He is little else than the expression of error. To suppose that sin, lust, hatred, envy, hypocrisy, revenge, have life abiding in them, is a terrible mistake. Life and Life’s idea, Truth and Truth’s idea, never make men sick, sinful, or mortal.”
—Mary Baker Eddy (1821–1910)