Bovine-associated mucoprotein: de novo synthesis by nonmammary tissues.

Bovine tissues were cultured in vitro in the presence of carbon-14 amino acids and tritiated hexosamine to examine the de novo synthesis of the milk fat globule glycoprotein bovine-associated mucoprotein, by selected tissues. Among tissues examined, the relative synthesis of bovine-associated mucoprotein was highest in mammary tissue. The de novo synthesized bovine-associated mucoprotein in mammary and lacrimal gland cultures when examined for incorporation of carbon-14, had similar sedimentation profiles in sucrose density gradients and incorporated the same relative amount of carbohydrate.

Quantitation of bovine beta 2-microglobulin: occurrence in body fluids, on milk fat globules and origin in milk.

The concns of bovine beta 2-microglobulin (beta 2M) and selected control proteins were measured using a competitive immunoassay to determine the origin of beta 2M in cows' milk. Using milk samples collected at various times, separated into different fractions and treated with protease inhibitors, it was established that beta 2M appears in cows' milk by protease-dependent degradation of the cellular fraction of milk, probably mononuclear cells, but is not derived from milk fat globules (MFG) or from polymorphonuclear leukocytes despite positive immunofluorescence of the former. The latter source could be eliminated by the induction of neutrophilia which produced no changes in beta 2M levels.

In vivo proteolytic activity of the mammary gland. Contribution to the origin of secretory component, beta 2-microglobulin and bovine-associated mucoprotein (BAMP) in cows milk.

Milk samples were collected from Holstein-Friesian cows at various times after milking (10-30 min; 30 min-10 hr) and treated with a protease inhibitor or control solution. Samples were then fractionated into whole, skimmed and cell-free skimmed milk aliquots. Some animals were treated with E.

A simple technique using skin implants to produce histocompatability (BoLA) typing sera.

We describe a technique to produce high-titered bovine lymphocytotoxic antisera using skin implants. The main advantage of this technique is that the skin does not need to be processed prior to implantation and no surgical skill is required. In addition, the skin can be stored for up to 2 weeks and can be shipped to other laboratories without special handling and without loss of immunogenicity.

The bovine major histocompatibility complex (BoLa): close linkage of the genes controlling serologically defined antigens and mixed lymphocyte reactivity.

Detection of linkage between genetic loci in cattle has been hampered by the lack of large full -sib families. A unique source of full-sib families is now available from embryo transplantation. Lymphocytes from six full-sib families, ranging in size from three to seven siblings, were tested for serologically defined BoLA antigens (BoLA-A).