Developmental pathways environmental

The exposure pathway and physicochemical characteristics of a particular environmental chemical can provide useful information on the likelihood of childhood exposure (chapter 5). Age-specific exposure pathways of particular relevance include those during the prenatal and early developmental years postnatally (e.g. placental transfer, breast milk, toys, soil, indoor air/dust, child-care centres). Exposures to persistent environmental chemicals are of special concern, since the internal exposure may continue and result in a level sufficient to cause effects during critical developmental stages, even after the external exposure has ceased or been removed. 

SHELLEY D. COPLEY is a professor of molecular, cellular and developmental biology at the University of Colorado at Boulder. Her research interests center on the molecular evolution of enzymes and metabolic pathways and protein structure-function relationships. Dr. Copley is a member of the Council of Fellows of the University of Colorado s Cooperative Institute for Research in Environmental Sciences. Dr. Copley served on the NSF Molecular Biochemistry Panel (1999-2003), was co-chair for the Gordon Conference on Enzymes, Coenzymes, and Metabolic Pathways (2004), and currently serves on the National Institutes of Health Genetic Variation and Evolution Study Section. 

It appears that an early evolutionary adaptation in plants was the ability to regulate levels of IAA via the interplay of both tryptophan-dependent and tryptophan-independent pathways (Figure 1) for IAA biosynthesis.66 The use of individual pathways can differ according to a plant s developmental stage and in response to various environmental stimuli.67-69 Tryptophan-dependent IAA biosynthesis is thought to occur via... 

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