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Summary Amylase activity has been estimated in the sera of 213 cattle by an amyloclastic method with potato amylose as the substrate with the addition of CaCl2. The method has been developed from that of Street and Close to overcome the problems of the high colour of bovine serum which would otherwise interfere with the assay. A relationship has been found between the serum amylase genotype detected on starch-gel and the total enzyme activity. The enzymes AmI-B and AmII-B in homozygous combinations have been found to have the highest activities. Age of animal has no significant effect on the total enzyme activity. Activity has been investigated in sera from three separate cattle populations and it has been found to be a highly heritable character. Heritability estimates of 49 % and 39 % by sib analysis and 75 % by the twin method have been obtained.

Summary Two genetically controlled polymorphic systems of amylase enzymes are described in sera from Friesian, Jersey, Guernsey, Hereford, Ayrshire and Charolais cattle. One of these Ami has been described previously and is controlled by two codominant alleles in British cattle, AmIB and AmIC. Evidence presented here suggests that it could be a gamma.amylase. The other enzyme which is described here for the first time has many of the properties of an alpha amylase. It is also polymorphic and controlled by two codominant alleles AmIIA and AmIIB. AmIIA is only present in low frequency. The inheritance of both enzyme systems has been studied in 419 families.

Peripheral blood lymphocytes (PBL) from cattle have been separated into T & B cell subpopulations using a panning technique. These T and B cell preparations have then been tested by direct and indirect complement mediated cytotoxicity tests with a series of monoclonal antibodies (Moabs) reacting with HLA class I and class II products. The anti-class I monoclonals were monomorphic or non-reactive and where reactive killed both B and T cells. The anti-class II monoclonals reacted only with B lymphocytes. There was no relationship between their reactivity pattern and any BoLA specificity.

The amylase (Ami) phenotypes have been determined in sera collected from 244 heifers before 6 months and after 2 years of age. Fifty of these animals exhibited a change in phenotype from Ami C to an apparent Ami BC with age. Using a modified electrophoretic technique these apparent heterozygotes were reclassified as Ami C(E). Eight hundred and nineteen cows, which had previously been shown to have a highly significant excess of heterozygotes at the Ami locus, were also retyped by this modified technique. The apparent heterozygote excess was not found as it was now possible to differentiate between Ami C(E) and Ami BC.

An earlier report that there is a high incidence (50 to 60 per cent) of cytotoxic antilymphocyte antibody in the sera of parous ewes is confirmed. This antibody is directed against paternally inherited antigens of the fetus. Antibody could be detected pre partum in four out of 34 primiparous ewes. However, there was no strong association between parity and the incidence of antibody. Antibody was also found in three out of 10 older rams which implies that pregnancy is not the only stimulus for antibody production.

SUMMARY Lymphocytotoxic sera have been produced in forty-seven cattle following skin grafting or lymphocyte immunization between dam-offspring pairs. From these sera seventy antilymphocyte reagents have been produced. Seven of the sera were operationally monospecific without absorption, thirty-seven others were made operationally monospecific and twenty-six partially purified by absorption with lymphocytes. Thirty-five of these sera were used in France and an additional thirty-five were used in Scotland. The inheritance of the antigenic factors detected by these sera has been studied in 480 cattle families and the evidence is consistent with the hypothesis that at least seventeen of the factors are inherited in a simple Mendelian fashion. Fourteen of these factors show evidence of linkage with at least one other factor and are likely to be controlled by a limited number of closely linked loci. It is suggested that these loci should be identified as the BLA region.

Homozygous cattle transferrin has been fractionated into six main peaks by DEAE-Sephadex chromatography. These correspond to the six transferrin components seen in starch gel electrophoresis of normal serum. In addition, six more minor components were isolated from DEAE-Sephadex, making 12 in all, and these could be divided into six pairs. Treatment of whole transferrin with neuraminidase yielded only two bands. Treatment of the individual fractionated bands showed that the slower band of each pair had the same mobility as the slow band from treated whole transferrin, while the faster band from each pair corresponded with the fast band of treated whole transferrin. These observations, and the results of sialic acid assays, showed that the difference between the pairs of bands was caused by differing numbers of sialic acid residues (0–5) per molecule of protein, but that sialic acid was not responsible for the difference between the bands within a pair. The mode of genetic control is discussed and probably involves three loci. Other physicochemical properties of cattle transferrins, namely, molecular weight, effect of iron addition, and behavior in isoelectric focusing, were also studied.

SUMMARYThe amylase (Am I) genotypes have been determined in sera from 834 cows comprising 562 Friesians, 77 Ayrshires, 106 Guernseys, 62 Jerseys and 27 crossbred cows. All of these cows had completed their third lactation and many were much older. There was a highly significant excess of heterozygotes at the Am I locus. This excess of heterozygotes was highest in high-yielding Friesian herds and there was a significant correlation between percentage heterozygotes and herd yield in the Friesians.

BoLA w6 is one of 16 specificities agreed upon at the 2nd International BoLA Workshop and many laboratories have produced sera reacting with this specificity. This paper presents evidence for at least four sub-groups in w6. Three Edinburgh sera showing identical reaction patterns in the 1st and 2nd BoLA workshops have been studied by absorption. One serum contained a single antibody population reacting with an epitope common to all w6 positive cells. The other two contained antibodies against the same common epitope, antibodies to epitopes on four sub-groups and an antibody reacting only with one subgroup w6.1. Another Edinburgh serum contained two populations of antibodies. One reacting with the common epitope and one with an epitope on two or possibly three subgroups. Immunisation between w6 positive individuals produced antisera to two subgroups without producing antibodies to common epitopes. At least two additional subgroups are likely to exist. These results indicate the presence of specificities unique to individual subtypes coupled with epitopes common to some and all w6 subgroups.

Summary 1. The inherited differential agglutinability of cattle erythrocytes is shown to be similarly expressed on ghosts and intact cells. 2. Removal of virtually all sialic acid by prolonged neuraminidase treatment does not alter the agglutinability status of ghosts prepared from either high or low agglutinable cells. Hence the differing sialic acid content of the two cell types is not responsible for the differential agglutinability. 3. The significance of these findings with respect to other well defined agglutination systems and current theories of membrane structure is discussed.

This paper reports on a study of1,033 Angoni cattle in the Eastern Province of Zambia. The animals came from two areas, one of which had frequent outbreaks of trypanosomiasis whilst the other was relatively free of clinical trypanosomiasis. Whole body tick collections were made from each animal and blood samples taken together with data on colour, sex, age and skinfold thickness. The blood samples were tested for parasites, red cell antigens and polymorphism at the transferrin (Tf), haemoglobin (Hb), albumin (Alb), amylase I (Am I) and amylase II (Am II) loci.

In an investigation of the expression of major histocompatibility complex (M.H.C.) antigens by cells infected and transformed in vitro by Theileria parasites, Spooner and Brown (1980) reported that the qualitative expression of such antigens remained unaltered by infection and transformation. However, in one instance cells taken from a dizygous twin and transformed by Theileria parva (Muguga) were found to have a different pattern of reactivity with the Edinburgh panel of Bovine Lymphocyte Antigen (BoLA) typing sera from those of the fresh peripheral blood lymphocytes (PBL) from the donor. Conversely PBL from the same animal transformed by T. annulata (Hissar) exhibited the same BoLA phenotype as uninfected PBL. The donor was a chimaera and it was suggested that the T. parva (Muguga) cell line arose from cells of a minor population within the chimaera, the inference being that this minor population was too small to be detectable in the standard BoLA-typing test. The results of BoLA typing of the parents of the cell donor were consistent with this hypothesis.

Summary. Two hundred and eighty-two alloantisera were submitted by 20 participating laboratories from 13 countries and tested against lymphocytes of 1298 cattle. The cell panel consisted of samples from 38 Bos taurus breeds, 11 Bos taurus crossbreeds, 4 Bos indicus breeds, 6 Bos taurus X Bos indicus, and a variety of other crossbred populations. Using a standardized lymphocytotoxicity test, all 17 previously identified BoLA specificities were confirmed. The workshop produced agreement on 16 new lymphocyte alloantigenic specificities. Three of the new specificities behaved as splits of previously identified BoLA specificities. Four of the new specificities behaved as alleles at the agreed BoLA-A locus. Seven new specificities are tentatively assigned to the BoLA-A locus but require further definition. Two new specificities may represent products of a second closely-linked BoLA locus.

Summary This paper describes the effect of gel buffer pH on the resolution of bovine serum amylase (Amylase I) isozymes in starch gel and the consequences for the understanding of the genetics of this locus. The two main findings are: (1) the existence of a satellite isozyme E to isozyme C which at pH 7.3 has the same mobility as the B isozyme but which at pH 8.0 migrates slower than B, and (2) the finding of three alleles AmI A, AmI B and AmI C in British cattle populations previously reported as having only AmI B and AmI C.

Ox red cell membranes have been extracted with butanol. The presence of F, V, J, L, R′, S′, and T′ has been detected in the protein fraction but all activity for other blood group antigens was lost. Protein has been used for isoimmunization in cattle and produced high titre antibodies specific for the injected antigen.