Site-specific Sulphur Amino Acid Uptake, Incorporation and Protein and DNA Synthesis in Bovine Claw Tissue Cultured in Vitro

The claw is a specialised structure of the bovine integument with function dependent on interaction between epidermis and dermis at a number of sites. These sites vary in the composition of horn-produced (Galbraith et al., 2002a) and contribution to suspensory function. Relatively little is known about the dynamics of nutrient uptake and protein and DNA synthesis at these functionally important locations. The sulphur containing amino acids are among important nutrients that support successful horn production. The dermis is known to supply nutrients and chemical signals to support proliferation and differentiation of horn-forming epidermal keratinocytes and expression of proteins involved in cytoskeleton and intercellular adhesion. The cytoskeletal intermediate filament proteins and associated proteins contain variably high concentrations of cysteine, which, in ...