Gene expression variation in Down's syndrome mice allows prioritization of candidate genes

Background  

Down's syndrome (DS), or trisomy 21, is a complex developmental disorder that exhibits many clinical signs that vary in occurrence and severity among patients. The molecular mechanisms responsible for DS have thus far remained elusive. We argue here that normal variation in gene expression in the population contributes to the heterogeneous clinical picture of DS, and we estimated the amplitude of this variation in 50 mouse orthologs of chromosome 21 genes in brain regions of Ts65Dn (a mouse model of DS). We analyzed the RNAs of eight Ts65Dn and eight euploid mice by real-time polymerase chain reaction.     

Protein expression in sputum of smokers and chronic obstructive pulmonary disease patients: a pilot study by CapLC-ESI-Q-TOF

The current report describes the use of CapLC-ESI-Q/TOF-MS for investigating the proteome profiles of hypertonic saline-induced sputum samples from 56 smokers. The severity of their lung disease ranged from normal (healthy smokers) to chronic bronchitis, chronic obstructive pulmonary disease (COPD), and COPD with emphysema. This pilot study examined the hypothesis that there were distinct differences in protein expression profiles that were related to the phenotype and cigarette smoking illness severity. A total of 203 unique proteins were identified. These may represent the most highly expressed proteins in induced sputum. Our results provide evidence that different proteins are expressed, as the disease progresses from health to more advanced stages, and support our contention that a proteomic approach would be beneficial in discovering selective molecules linked to specific COPD stages.     

Synthetic viability genomic screening defines Sae2 function in DNA repair

DNA double-strand break (DSB) repair by homologous recombination (HR) requires 3′ single-stranded DNA (ssDNA) generation by 5′ DNA-end resection. During meiosis, yeast Sae2 cooperates with the nuclease Mre11 to remove covalently bound Spo11 from DSB termini, allowing resection and HR to ensue. Mitotic roles of Sae2 and Mre11 nuclease have remained enigmatic, however, since cells lacking these display modest resection defects but marked DNA damage hypersensitivities. By combining classic genetic suppressor screening with high-throughput DNA sequencing, we identify Mre11 mutations that strongly suppress DNA damage sensitivities of sae2Δ cells. By assessing the impacts of these mutations at the cellular, biochemical and structural levels, we propose that, in addition to promoting resection, a crucial role for Sae2 and Mre11 nuclease activity in mitotic DSB repair is to facilitate the removal of Mre11 from ssDNA associated with DSB ends. Thus, without Sae2 or Mre11 nuclease activity, Mre11 bound to partly processed DSBs impairs strand invasion and HR.     

Methyl jasmonate affects phenolic metabolism and gene expression in blueberry (Vaccinium corymbosum)

Blueberry (Vaccinium corymbosum) is a fruit very much appreciated by consumers for its antioxidant potential and health‐promoting traits. Its beneficial potential properties are mainly due to a high content of anthocyanins and their amount can change after elicitation with methyl jasmonate. The aim of this work is to evaluate the changes in expression of several genes, accumulation of phenolic compounds and alterations in antioxidant potential in two different blueberry cultivars (‘Duke’ and ‘Blueray’) in response to methyl jasmonate (0.1 mM). Results showed that 9 h after treatment, the expression of phenylalanine ammonium lyase, chalcone synthase and anthocyanidin synthase genes was stimulated more in the ‘Blueray’ variety. Among the phenols measured an increase was recorded also for epicatechin and anthocyanin concentrations. ‘Duke’ is a richer sourche of anthocyanins compared to ‘Blueray’, treatment with methyl jasmonate promoted in ‘Blueray’ an increase in pigments as well as in the antioxidant potential, especially in fully ripe berries, but treated ‘Duke’ berries had greater levels, which were not induced by methyl jasmonate treatment. In conclusion, methyl jasmonate was, in some cases, an effective elicitor of phenolic metabolism and gene expression in blueberry, though with different intensity between cultivars.