Encyclopaedia
to blood

Group blood - the description of individual antigene characteristics eritrotsitov, defined through a chemical compound of carbohydrates and fibers on a membrane eritrotsitov animals.
in a membrane eritrotsitov the person than 300 various antigene determinant which molecular structure is coded corresponding gene alleljami chromosomal loci contains more. The quantity such allelej and loci precisely is not established now.
the term «the blood group» characterises systems eritrotsitarnyh the antigenes supervised by certain loci, containing various number allelnyh genes, such, for example, as A, B and 0 in system AB0. The term «blood type» reflects its antigene phenotype (full antigene "portrait", or an antigene profile) - set of all group antigene characteristics of blood, serologicheskoe expression of all complex of inherited genes of group of blood.
two major classifications of group of blood of the person is system AB0 and a Rhesus factor-system.
46 classes of other antigenes from which the majority meets much less often, than AB0 and a Rhesus factor are known also.

system AB0
It is known four basic allelnyh a gene of this system: A1, A and # 178;, B and 0. The gene locus for these allelej is on a long shoulder of a chromosome 9. The basic products of first three genes - genes A1, A and # 178; and B, but not a gene 0 - are specific enzymes glikoziltransferazy, belonging to the class transferaz. These glikoziltransferazy transfer specific sugar - N-atsetil-D-galaktozamin in case of A1 and A and # 178; Types glikoziltransferaz, and D-galaktozu in case of B-type glikoziltransferazy. Thus all three types glikoziltransferaz attach a transferable carbohydrate radical to an alpha link short oligosaharidnyh chains.

substrata glikozilirovanija these glikoziltransferazami are, in particular and in particular, just carbohydrate parts glikolipidov and glikoproteidov membranes eritrotsitov, and in much smaller degree - glikolipidy and glikoproteidy other fabrics and organism systems. Specific glikozilirovanie glikoziltransferazoj A or B one of superficial antigenes - aggljutinogena - eritrotsitov that or other sugar (N-atsetil-D-galaktozaminom or D-galaktozoj) also forms specific aggljutinogen A or B.

In plasma of blood of the person can contain aggljutininy and #945; and and #946;, in eritrotsitah - aggljutinogeny A and B, and from fibers A and and #945; one contains and only one, the same - for fibers B and and #946;.

Thus, exists four admissible combinations; what of them is characteristic for the given person, defines its group of blood:
) and #945; and and #946;: the first (0)
A and and #946;: the second (A)
and #945; and B: the third (B)
A and B: the fourth (AB)

System Rh (Rhesus factor-system)
the Rhesus factor is an antigene (fiber) which is on a surface of red blood little bodies (eritrotsitov). It is found out in 1919 g in blood of monkeys, and later - and in people. About 85 % of people have a Rhesus factor and accordingly are a Rhesus factor-positive. The others of 15 % at which it is not present, - a Rhesus factor-are negative. The Rhesus factor plays the important role in formation so-called gemoliticheskoj the jaundice of newborns called owing to the Rhesus factor-conflict of blood little bodies immunizovannoj of mother and a fruit.