In article <199703161455.XAA15243 at chollian.dacom.co.kr>,
=?EUC-KR?B?s7I=?= =?EUC-KR?B?wb65zg==?= <urimini at dacom.co.kr> wrote:
>Hello, every netters.
>I have some questions about human blood type.
>>The relationship bewtween antigen and antibody in blood type is irony.
>In the case of O type, there is no antigen(A and B).
>In spite of this, O type human blood has antibody for A and B always.
>>I think that the direct origin of antibody is exogenous...
>As a result of coevolution with bacteria...??????
>>Hmmm.
>Anyone can tell me about this, mail to me.
This seems to be the case. The ABO blood antigens are carbohydrate, and are
very similar to antigens on intestinal flora, etc. If your red blood cells
carry an antigen, the B cells (which make antibodies) which recognize it will
be deleted or inactivated. Otherwise, as in the case of type O blood, cross-
reacting bacterial antigens will cause antibody production.
As a side note, I am rather intrigued by the genetics of ABO blood types.
O type blood is a recessive trait, yet O is far and away the most common
blood type, suggesting that there was a strong selective pressure for the
trait. Perhaps this is because people with type O blood *can* produce
antibodies to those carbohydrates, allowing an improved anti-bacterial
immune response.
BioKen
--
Ken Frauwirth (MiSTie #33025) _ _
frauwirt at mendel.berkeley.edu |_) * |/ (_ |\ |
http://www.ocf.berkeley.edu/~frauwirt/ |_) | () |\ (_ | \|
DNRC Title: Chairman of Joint Commission on In-duh-vidual Affairs
