title: Evaluating microarrays using a semiparametric approach: application to the central carbon metabolism of Escherichia coli BL21 and JM109.
abstract: Escherichia coli K (JM109) and E. coli B (BL21) are strains used routinely for recombinant protein production. These two strains grow and respond differently to environmental factors such as glucose and oxygen concentration. The differences have been attributed to differential expression of individual genes that constitute certain metabolic pathways that are part of the central carbon metabolism. By implementing a semiparametric algorithm, which is based on a density ratio model, it was possible to compare and quantify the expression patterns of groups of genes involved in several central carbon metabolic pathways. The groups comprising the glyoxylate shunt, TCA cycle, fatty acid, and gluconeogenesis and anaplerotic pathways were expressed differently between the two strains, whereas no differences were apparent for the groups comprising either glycolysis or the pentose phosphate pathway. These results further characterized differences between the two E. coli strains and illustrated the potency of the semiparametric algorithm.
authors.affiliation: Biotechnology Unit, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 14A, Room 170, 9000 Rockville Pike, Bethesda, MD 20892, USA.
authors.forename: Je-Nie
authors.initials: JN
authors.lastname: Phue
authors.forename: Benjamin
authors.initials: B
authors.lastname: Kedem
authors.forename: Pratik
authors.initials: P
authors.lastname: Jaluria
authors.forename: Joseph
authors.initials: J
authors.lastname: Shiloach
mesh_terms: D000465:Algorithms; D002244:Carbon / Q000378:metabolism*; D002952:Citric Acid Cycle / Q000235:genetics; D004926:Escherichia coli / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism; D005943:Gluconeogenesis / Q000235:genetics; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis / Q000235:genetics; D006038:Glyoxylates / Q000378:metabolism; D008954:Models, Biological; D008957:Models, Genetic; D015233:Models, Statistical; D020411:Oligonucleotide Array Sequence Analysis / Q000706:statistics & numerical data*; D010427:Pentose Phosphate Pathway / Q000235:genetics; D013045:Species Specificity
chemical_list: D005227:Fatty Acids; D006038:Glyoxylates; D002244:Carbon; D005947:Glucose; C031150:glyoxylic acid