The J Blood‐Group Substance of Cattle

Abstract

I n cattle with J blood-group substance both on erythrocytes and dissolved in serum, J activity was found in the total lipids extracted from erythrocytes, but not in the proteins precipitated by lipid extraction and not in the mucoproteins prepared from erythrocytes. Serum from these animals, however, does not only exhibit J activity of its total lipid, but also of its mucoproteins and of its residue after lipid extraction. This serum, therefore, contains the J substance in a t least two different forms, as a lipoprotein and as a mucoprotein. Only the J lipoprotein is able to coat bovine erythrocytes during a postnatal period. It is suggested that hydrophobic groups are responsible for the attachment of the J substance to the erythrocytes.I n cattle with J substance only in serum, coating of erythrocytes is missing. This is apparently due to the finding that the serum from these animals contains J mucoproteins, but virtually no J lipoprotein. Since the determinant of the J lipoprotein has been found in the glycosphingolipid fraction the genetically fixed difference between animals which have J substance on erythrocytes and in serum and those which have it only in serum seems to consist in the inability of the latter animals to synthesize a glycosphingolipid containing the sequence of sugars which is responsible for J specificity.I n contrast to other bovine blood-group substances the J substance is primarily a soluble plasma constituent [l], which is passively acquired by the erythrocytes from the plasma. Young calves do not carry the J substance on the erythrocytes until 4-12 weeks after birth. After this period the J substance is absorbed from the plasma onto the erythrocytes and remains detectable there for life. I n some animals, however, this coating of erythrocytes is missing. Thus, adult cattle may be classified [2] into three groups: those with J substance both on the cells and in the serum, those with J substance only in the serum, and those lacking J substance a t all.The mechanism of coating in animals which contain J substance on erythrocytes and serum is not clear, nor is it known why the coating of erythrocytes is missing in animals which contain J substance only in serum. It is, however, clear that the absorption of J substance from the serum onto the cells is dependent upon the serum, not upon the cells, since cells from animals in which only the serum contains J substance can be coated with J substance by incubation i n vitro with serum from animals which also contain J substance in erythrocytes [3]. Furthermore, it is believed that the absorption of J substance is a consequence of the concentration of J in the plasma [2] since sera of cattle with J substance only in the serum usually contain relatively low concentrat,ions of J.

Occurrence of J blood group activities in lipid and non‐lipid fractions of organs and body fluids of cattle

“…In fact, we found the non-lipid fractions of bile, faeces and seminal plasma to be J-active. On the other hand, J activity was also found in non-lipid fractions of milk and blood serum (Schroffel et al, 1971) that are not directly associated with mucous secretions. It may therefore be speculated that the non-lipid J substance may exist in an additional form other than mucoprotein, e.g.…”

“…as a glycoprotein with a low percentage of carbohydrate that is also precipitated by the lipid extraction procedure. In addition to a non-lipidic J substance, faeces, seminal plasma, and blood serum (Schroffel et al, 1971) also contain a lipidic J substance. It was demonstrated in a previous paper (Thiele & Koch, 1970) that the J lipid of serum is dissolved as a lipoprotein.…”

“…The Lewis blood-group substance of man (Sneath & Sneath, 1955), the J substance of cattle (Stormont, 1949), the R substance of sheep (Rendel, 1957), and the A substance of pig (Andresen, 1962) are examples of those kinds of blood-group substances. It is well established that there is a diversity of carriers of the J blood-group substance dissolved in bovine serum (Schroffel et al, 1971). Thus, the J activity was found in the lipid fraction as well as in the protein-containing residue obtained after lipid extraction of bovine J-positive serum.…”

“…Since we know (Schroffel et al, 1971;Thiele & Koch, 1973) that the J activity can be demonstrated in both the total lipids and the protein-containing non-lipid residue of J-positive serum, we are able to extend these studies to tissues and body fluids other than serum. By those means it seems not only possible to test various tissues for J activity, but also to discriminate between lipid-bound and non-lipidbound J activity.…”

Distribution of the A Blood Group Activity on Lipid and Nonlipid Fractions of Pig Organs

“…The A blood group antigen of pig [2] and the J blood group antigen of cattle [3] are examples of those kinds of an tigens. It has been shown in previous papers that the J activity of cattle [4] as well as the A activity of pig [5] can be found in both a lipid and a nonlipid fraction of serum. Fur thermore, it has been demonstrated [6,10] that the determinant of the nonlipid J sub stance of bovine serum is transferred to a 1 Supported by «Forschungsmittel des Landes Niedersachsen».…”