Genome-wide identification of transcriptional start sites in the haloarchaeon Haloferax volcanii based on differential RNA-Seq (dRNA-Seq)

BMC Genomics

Research Article

Rolf Hilker¹  Karina A. Haas²  Anita Marchfelder²  Friedhelm Pfeiffer³  Daniela Näther-Schindler⁴  Jörg Soppa⁴  Matthias Hammelmann⁴  Julia Babski⁴  Anke Becker⁵  Konrad U. Förstner⁶  Cynthia M. Sharma⁶ 

[1] Bioinformatik und Systembiologie, University of Gießen, Heinrich-Buff-Ring 58, 35392, Gießen, Germany;Biologie II, University of Ulm, 89069, Ulm, Germany;Computational Biology Group, MaxPlanckInstitute of Biochemistry, Am Klopferspitz 18, 82152, Martinsried, Germany;Institute for Molecular Biosciences, Goethe University, Biocentre, Max-von-Laue-Str. 9, D-60439, Frankfurt, Germany;LOEWE-Center for Synthetic Microbiology, Hans-Meerwein-Str., 35032, Marburg, Germany;Research Center for Infectious Diseases (ZINF), University of Würzburg, Josef-Schneider-Str. 2/D15, 97080, Würzburg, Germany;

关键词: Archaea;    Haloferax volcanii;    dRNA-Seq;    Transcriptome;    Promoter;    Leaderless transcript;    Non-coding RNA;    sRNA;    Antisense RNA;   

DOI  :  10.1186/s12864-016-2920-y

 received in 2016-03-09, accepted in 2016-07-07,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundDifferential RNA-Seq (dRNA-Seq) is a recently developed method of performing primary transcriptome analyses that allows for the genome-wide mapping of transcriptional start sites (TSSs) and the identification of novel transcripts. Although the transcriptomes of diverse bacterial species have been characterized by dRNA-Seq, the transcriptome analysis of archaeal species is still rather limited. Therefore, we used dRNA-Seq to characterize the primary transcriptome of the model archaeon Haloferax volcanii.ResultsThree independent cultures of Hfx. volcanii grown under optimal conditions to the mid-exponential growth phase were used to determine the primary transcriptome and map the 5′-ends of the transcripts. In total, 4749 potential TSSs were detected. A position weight matrix (PWM) was derived for the promoter predictions, and the results showed that 64 % of the TSSs were preceded by stringent or relaxed basal promoters. Of the identified TSSs, 1851 belonged to protein-coding genes. Thus, fewer than half (46 %) of the 4040 protein-coding genes were expressed under optimal growth conditions. Seventy-two percent of all protein-coding transcripts were leaderless, which emphasized that this pathway is the major pathway for translation initiation in haloarchaea. A total of 2898 of the TSSs belonged to potential non-coding RNAs, which accounted for an unexpectedly high fraction (61 %) of all transcripts. Most of the non-coding TSSs had not been previously described (2792) and represented novel sequences (59 % of all TSSs). A large fraction of the potential novel non-coding transcripts were cis-antisense RNAs (1244 aTSSs). A strong negative correlation between the levels of antisense transcripts and cognate sense mRNAs was found, which suggested that the negative regulation of gene expression via antisense RNAs may play an important role in haloarchaea. The other types of novel non-coding transcripts corresponded to internal transcripts overlapping with mRNAs (1153 iTSSs) and intergenic small RNA (sRNA) candidates (395 TSSs).ConclusionThis study provides a comprehensive map of the primary transcriptome of Hfx. volcanii grown under optimal conditions. Fewer than half of all protein-coding genes have been transcribed under these conditions. Unexpectedly, more than half of the detected TSSs belonged to several classes of non-coding RNAs. Thus, RNA-based regulation appears to play a more important role in haloarchaea than previously anticipated.

【 授权许可】

CC BY   
© The Author(s). 2016