Maes A.,University Paris Diderot |
Gracia C.,University Paris Diderot |
Innocenti N.,Albanova University Center |
Innocenti N.,Combient AB |
And 6 more authors.
Nucleic Acids Research | Year: 2017
Polyadenylation is thought to be involved in the degradation and quality control of bacterial RNAs but relatively few examples have been investigated. We used a combination of 5'-tagRACE and RNA-seq to analyze the total RNA content from a wild-type strain and froma poly(A)polymerase deletedmutant. A total of 178 transcripts were either up- or down-regulated in the mutant when compared to the wild-type strain. Poly(A)polymerase up-regulates the expression of all genes related to the FliA regulon and several previously unknown transcripts, including numerous transporters. Notable down-regulation of genes in the expression of antigen 43 and components of the type 1 fimbriae was detected. The major consequence of the absence of poly(A)polymerase was the accumulation of numerous sRNAs, antisense transcripts, REP sequences and RNA fragments resulting from the processing of entire transcripts. A new algorithm to analyze the position and composition of post-transcriptional modifications based on the sequence of unencoded 3'-ends, was developed to identify polyadenylated molecules. Overall our results shed new light on the broad spectrum of action of polyadenylation on gene expression and demonstrate the importance of poly(A) dependent degradation to remove structured RNA fragments. © The Author(s) 2016.
Torma P.T.,AaltoUniversity |
Ali M.,AaltoUniversity |
Svensk O.,AaltoUniversity |
Suihkonen S.,AaltoUniversity |
And 5 more authors.
CrystEngComm | Year: 2010
A study of GaN films and nitride based light emitting diodes (LEDs) grown on low density pillar structure (LDPS) and high density pillar structure (honeycomb like) sapphires patterned by chemical wet etching is described. Both types of patterned sapphire substrate (PSS) offered reduced defect density and improved performance of near-ultraviolet LED. In the case of LDPS patterned sapphire the correct choice of the pillar depth was found to be crucial for high quality crystal growth. A reduction of threading dislocation (TD) density from the level of 108 cm-2 down to the level of 2 × 109 cm-2 was observed. It was found that mostly enhanced light extraction rather than improved material quality caused the improvement of the LED performance. © 2010 The Royal Society of Chemistry.