A transcriptome approach towards understanding the development of ripening capacity in Bartlett pears (Pyrus communis L.).

The capacity of European pear fruit (Pyrus communis L.) to ripen after harvest develops during the final stages of growth on the tree. The objective of this study was to characterize changes in Bartlett pear fruit physico-chemical properties and transcription profiles during fruit maturation leading to attainment of ripening capacity

Measuring socio-economic data in tuberculosis prevalence surveys

Addressing social determinants in the field of tuberculosis (TB) has received great attention in the past years, mainly due to the fact that worldwide TB incidence has not declined as much as expected, despite highly curative control strategies. One of the objectives of the World Health Organization Global Task Force on TB Impact Measurement is to assess the prevalence of TB disease in 22 high-burden countries by active screening of a random sample of the general population. These surveys provide a unique opportunity to assess socio-economic determinants in relation to prevalent TB and its risk factors. This article describes methods of measuring the socio-economic position in the context of a TB prevalence survey. An indirect measurement using an assets score is the most feasible way of doing this. Several examples are given from recently conducted prevalence surveys of the use of an assets score, its construction, and the analyses of the obtained dat

A transcriptome approach towards understanding the development of ripening capacity in 'Bartlett' pears (Pyrus communis L.)

Background: The capacity of European pear fruit (Pyrus communis L.) to ripen after harvest develops during the final stages of growth on the tree. The objective of this study was to characterize changes in 'Bartlett' pear fruit physico-chemical properties and transcription profiles during fruit maturation leading to attainment of ripening capacity. Results: The softening response of pear fruit held for 14days at 20°C after harvest depended on their maturity. We identified four maturity stages: S1-failed to soften and S2- displayed partial softening (with or without ET-ethylene treatment); S3 - able to soften following ET; and S4 - able to soften without ET. Illumina sequencing and Trinity assembly generated 68,010 unigenes (mean length of 911bp), of which 32.8% were annotated to the RefSeq plant database. Higher numbers of differentially expressed transcripts were recorded in the S3-S4 and S1-S2 transitions (2805 and 2505 unigenes, respectively) than in the S2-S3 transition (2037 unigenes). High expression of genes putatively encoding pectin degradation enzymes in the S1-S2 transition suggests pectic oligomers may be involved as early signals triggering the transition to responsiveness to ethylene in pear fruit. Moreover, the co-expression of these genes with Exps (Expansins) suggests their collaboration in modifying cell wall polysaccharide networks that are required for fruit growth. K-means cluster analysis revealed that auxin signaling associated transcripts were enriched in cluster K6 that showed the highest gene expression at S3. AP2/EREBP (APETALA 2/ethylene response element binding protein) and bHLH (basic helix-loop-helix) transcripts were enriched in all three transition S1-S2, S2-S3, and S3-S4. Several members of Aux/IAA (Auxin/indole-3-acetic acid), ARF (Auxin response factors), and WRKY appeared to play an important role in orchestrating the S2-S3 transition. Conclusions: We identified maturity stages associated with the development of ripening capacity in 'Bartlett' pear, and described the transcription profile of fruit at these stages. Our findings suggest that auxin is essential in regulating the transition of pear fruit from being ethylene-unresponsive (S2) to ethylene-responsive (S3), resulting in fruit softening. The transcriptome will be helpful for future studies about specific developmental pathways regulating the transition to ripening. © 2015 Nham et al