Genetic control of wheat quality: interactions between chromosomal regions determining protein content and composition, dough rheology, and sponge and dough baking properties.

While the genetic control of wheat processing characteristics such as dough rheology is well understood, limited information is available concerning the genetic control of baking parameters, particularly sponge and dough (S&D) baking. In this study, a quantitative trait loci (QTL) analysis was performed using a population of doubled haploid lines derived from a cross between Australian cultivars Kukri x Janz grown at sites across different Australian wheat production zones (Queensland in 2001 and 2002 and Southern and Northern New South Wales in 2003) in order to examine the genetic control of protein content, protein expression, dough rheology and sponge and dough baking performance. The study highlighted the inconsistent genetic control of protein content across the test sites, with only two loci (3A and 7A) showing QTL at three of the five sites.

Repetitive DNA elements as mediators of genomic change in response to environmental cues.

There is no logical or theoretical barrier to the proposition that organismal and cell signaling could transduce environmental signals into specific, beneficial changes in primary structure of noncoding DNA via repetitive element movement or mutation. Repetitive DNA elements, including transposons and microsatellites, are known to influence the structure and expression of protein-coding genes, and to be responsive to environmental signals in some cases. These effects may create fodder for adaptive evolution, at rates exceeding those observed for point mutations.

Microsatellite mutation directed by an external stimulus.

Microsatellites are regions of DNA containing tandem repeats of a core 2-6 bp nucleotide sequence. To test the hypothesis that microsatellite mutation can be directed by exposure to specific external cues, control and treatment groups of resistant and susceptible wheat varieties were grown under controlled conditions and genotyped at a number of microsatellite loci that map to chromosomes known to contain Fusarium head blight (FHB) resistance/susceptibility loci. Genotyping was undertaken both prior to and following exposure to Fusarium graminearum, the FHB pathogen.

Normal regulation of elevated plasma ghrelin concentrations in dialysis patients.

Background: Chronic renal failure is often associated with malnutrition, and malnourished patients are subject to increased morbidity and mortality. Therefore plasma concentrations of the stomach-derived peptide hormone ghrelin, which has been shown to exert potent GH-releasing and appetite-stimulating effects, were determined and correlated with nutritional parameters.

Methods: Twenty-four patients (15 male, 9 female) undergoing hemodialysis (HD) were studied.

Plasma ghrelin concentrations are not regulated by glucose or insulin: a double-blind, placebo-controlled crossover clamp study.

Ghrelin plasma concentrations increase during fasting and fall rapidly after nutrient ingestion. We hypothesized that insulin or glucose could regulate ghrelin secretion by a feedback mechanism. In this randomized, double-blind, placebo-controlled crossover study, three different study days were carried out in nine healthy volunteers (age 26 +/- 6 years).