Search

The bovine Muc1 protein is synthesized by mammary epithelial cells and shed into milk as an integral component of the milk fat globule membrane; however, the structure and functions of this mucin, particularly in relation to lactation, are poorly defined. The objectives of this investigation were to investigate the Muc1 gene and protein structures in the context of lactation and to test the hypothesis that Muc1 has a role in innate immune defense. Polymerase chain reaction analysis of genomic DNA from 630 cattle revealed extensive polymorphism in the variable number of tandem repeats (VNTR) in the bovine Muc1 gene. Nine allelic variants spanning 7 to 23 VNTR units, each encoding 20 AA, were identified. Three alleles, containing 11, 14, and 16 VNTR units, respectively, were predominant. In addition, a polymorphism in one of the VNTR units has the potential to introduce a unique site for N-linked glycosylation. Statistical analysis indicated weak associations between the VNTR alleles and milk protein and fat percentages in a progeny-tested population of Holstein-Friesian dairy cattle. No association with somatic cell count could be demonstrated. Bovine Muc1 was purified from milk fat globule membranes and characterized. The protein was highly glycosylated, primarily with O-linked sialylated T-antigen [Neu5Ac(α2–3)-Gal(β1–3)-GalNAcα1] and, to a lesser extent, with N-linked oligosaccharides, which together accounted for approximately 60% of the apparent mass of Muc1. Purified bovine Muc1 directly bound fluorescently labeled Escherichia coli BioParticles (Invitrogen, Mount Waverley, Australia) and inhibited their binding to bovine mammary epithelial cells grown in vitro.

Appropriate information, participatory processes and wise practice agreements are key elements in reducing conflicts over the use and management of coastal resources. In this work we describe the evolution of a cooperative learning approach to coastal floodplain management, incorporating these elements. Government-encouraged drainage of coastal floodplains in eastern Australia caused accelerated oxidation of acid sulfate soils and export of diffuse acidic drainage into streams. Major impacts on infrastructure, ecology, fisheries and aquaculture resulted. In the Tweed River estuary, in 1987, all gilled organisms were killed by acid discharge from floodplain canelands. This generated major conflicts between fishers, environmentalists and sugarcane producers. The cooperative learning partnership that evolved, involving cane farmers, local government, and researchers, has produced better strategies for managing sulfidic estuarine areas and mitigating impacts on downstream ecosystems. These underpinned mandatory best practice management guidelines for the NSW sugar industry. Increases in productivity and decreases in acid discharge have resulted. Fish kills on the Tweed and elsewhere also generated broader, parallel whole-of-government approaches that led to Australia's national strategy for managing coastal acid sulfate soils and the rapid adoption of information and strategies across Australia.

Different sectors of society claim rights to use valuable coastal ecosystem resources. Conflicts over their use are therefore inevitable. In eastern Australia, government-encouraged development and drainage of coastal flood plains, principally for agricul