Shawn F. Sorrells

Because of the huge size of the common wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD) genome of 17,300 Mb, sequencing and mapping of the expressed portion is a logical first step for gene discovery. Here we report mapping of 7104 expressed sequence tag (EST) unigenes by Southern hybridization into a chromosome bin map using a set of wheat aneuploids and deletion stocks. Each EST detected a mean of 4.8 restriction fragments and 2.8 loci. More loci were mapped in the B genome (5774) than in the A (5173) or D (5146) genomes. The EST density was significantly higher for the D genome than for the A or B. In general, EST density increased relative to the physical distance from the centromere. The majority of EST-dense regions are in the distal parts of chromosomes. Most of the agronomically important genes are located in EST-dense regions. The chromosome bin map of ESTs is a unique resource for SNP analysis, comparative mapping, structural and functional analysis, and polyploid evolution, as well as providing a framework for constructing a sequence-ready, BAC-contig map of the wheat genome.

Although the anti-inflammatory actions of glucocorticoids (GCs) are well established, evidence has accumulated showing that proinflammatory GC effects can occur in the brain, in a poorly understood manner. Using electrophoretic mobility shift assay, real-time PCR, and immunoblotting, we investigated the ability of varying concentrations of corticosterone (CORT, the GC of rats) to modulate lipopolysaccharide (LPS)-induced activation of NF-κB (nuclear factor κB), expression of anti- and proinflammatory factors and of the MAP (mitogen-activated protein) kinase family [ERK (extracellular signal-regulated kinase), p38, and JNK/SAPK (c-Jun N-terminal protein kinase/stress-activated protein kinase)], and AKT. In the frontal cortex, elevated CORT levels were proinflammatory, exacerbating LPS effects on NF-κB, MAP kinases, and proinflammatory gene expression. Milder proinflammatory GCs effects occurred in the hippocampus. In the absence of LPS, elevated CORT levels increased basal activation of ERK1/2, p38, SAPK/JNK, and AKT in both regions. These findings suggest that GCs do not uniformly suppress neuroinflammation and can even enhance it at multiple levels in the pathway linking LPS exposure to inflammation.