Search PubMed⌕ Search

Biomedical subjects

Mark E Williams

Publications and source records attributed to Mark E Williams.

21 records · Page 2Linked to original sources

DNA array profiling of gene expression changes during maize embryo development.

We are using DNA microarray-based gene expression profiling to classify temporal patterns of gene expression during the development of maize embryos, to understand mRNA-level control of embryogenesis and to dissect metabolic pathways and their interactions in the maize embryo. Genes involved in carbohydrate, fatty acid, and amino acid metabolism, the tricarboxylic acid (TCA) cycle, glycolysis, the pentose phosphate pathway, embryogenesis, membrane transport, signal transduction, cofactor biosynthesis, photosynthesis, oxidative phosphorylation and electron transfer, as well as 600 random complementary DNA (cDNA) clones from maize embryos, were arrayed on glass slides. DNA arrays were hybridized with fluorescent dye-labeled cDNA probes synthesized from kernel and embryo poly(A)(+)RNA from different stages of maize seed development. Several characteristic developmental patterns of expression were identified and correlated with gene function. Patterns of coordinated gene expression in the TCA cycle and glycolysis were analyzed in detail. The steady state level of poly(A)(+) RNA for many genes varies dramatically during maize embryo development. Expression patterns of genes coding for enzymes of fatty acid biosynthesis and glycolysis are coordinately regulated during development. Genes of unknown function may by assigned a hypothetical role based on their patterns of expression resembling well characterized genes. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s10142-002-0046-6.

Blotting, Northern↗

Medicare medical nutrition therapy: legislative process and product.

The new Medicare benefit, medical nutrition therapy (MNT), came into effect January 2002-the product of a lengthy legislative process. Over several years, evidence-based advocacy by groups such as the American Diabetic Association and the National Kidney Foundation led to a legislative product that was introduced and passed by Congress. More recently, the legislation entered an implementation process, including the most recent Coverage Determination phase. The definition of MNT and the scientific evidence supporting it are presented. Evidence-based nutrition now enters a new phase of implementation and additional analysis.

Dietetics↗