Selected Contribution: A three-dimensional model for assessment of in vitro toxicity in Balaena mysticetus renal tissue

This study established two- and three-dimensional renal proximal tubular ce ll cultures of the endangered species bowhead whale (Balaena mysticetus), d eveloped SV40-transfected cultures, and cloned the 61-amino acid open readi ng frame for the metallothionein protein, the primary binding site for heav y metal contamination in mammals. Microgravity research, modulations in mec hanical culture conditions (modeled microgravity), and shear stress have sp awned innovative approaches to understanding the dynamics of cellular inter actions, gene expression, and differentiation in several cellular systems. These investigations have led to the creation of ex vivo tissue models capa ble of serving as physiological research analogs for three-dimensional cell ular interactions. These models are enabling studies in immune function, ti ssue modeling for basic research, and neoplasia. Three-dimensional cellular models emulate aspects of in vivo cellular architecture and physiology and may facilitate environmental toxicological studies aimed at elucidating bi ological functions and responses at the cellular level. Marine mammals occu py a significant ecological niche (72% of the Earth's surface is water) in terms of the potential for information on bioaccumulation and transport of terrestrial and marine environmental toxins in high-order vertebrates. Few ex vivo models of marine mammal physiology exist in vitro to accomplish the aforementioned studies. Techniques developed in this investigation, based on previous tissue modeling successes, may serve to facilitate similar rese arch in other marine mammals.