Genome-wide mapping of 5-hydroxymethylcytosine in three rice cultivars reveals its preferential localization in transcriptionally silent transposable element genes

5-Hydroxymethylcytosine (5hmC), a modified form of cytosine that is considered the sixth nucleobase in DNA, has been detected in mammals and is believed to play an important role in gene regulation. In this study, 5hmC modification was detected in rice by employing a dot-blot assay, and its levels was further quantified in DNA from different rice tissues using liquid chromatography-multistage mass spectrometry (LC-MS/MS/MS). The results showed large intertissue variation in 5hmC levels. The genome-wide profiles of 5hmC modification in three different rice cultivars were also obtained using a sensitive chemical labelling followed by a next-generation sequencing method. Thousands of 5hmC peaks were identified, and a comparison of the distributions of 5hmC among different rice cultivars revealed the specificity and conservation of 5hmC modification. The identified 5hmC peaks were significantly enriched in heterochromatin regions,and mainly located in transposable element (TE) genes, especially around retrotransposons. The correlation analysis of 5hmC and gene expression data revealed a close association between 5hmC and silent TEs. These findings provide a resource for plant DNA 5hmC epigenetic studies and expand our knowledge of 5hmC modification.

Firms in international trade: importers’ and exporters’ heterogeneity in Italian manufacturing industry

Combining data on structural characteristics and economic performance for a large sample of Italian firms with data on exporting and importing activity, we uncover evidence supporting recent theories on firm heterogeneity and international trade, together with some new facts. In particular, we find that importing is associated with substantial firm heterogeneity. First, we document that trade is more concentrated than employment and sales, and show that importing is even more concentrated than exporting both within sectors and along the sector- and country-extensive margins. Second, while supporting the fact that firms involved in both are the best performers, we also find that firms involved only in importing activities perform better than those involved only in exporting. Our evidence suggests there is a strong self-selection effect in the case of importers and the performance premia of internationalised firms correlate relatively more with the degree of geographical and sectoral diversification of imports.

Balkanisation of banking damages international trade and UK GDP

Balkanisation is a way to describe the breakdown of cross-border banking, as nervous lenders retreat in particular from the more troubled parts of the Eurozone or at least try to isolate operations within national boundaries. It is increasing at the Bank level, however the senior policy makers consider this a negative trend – Mario Draghi, president of the European Central Bank, has talked of the need to “repair this financial fragmentation” and Mark Carney, head of global regulatory body the Financial Stability Board, [and now Governor of the Bank of England] has warned that deglobalising finance will hurt growth and jobs by “reducing financial capacity and systemic resilience”. In this article I would like to examine the impact of banking balkanisation on international trade and provide some initial thoughts about remedies for excessive risk in a banking non-balkanising world.