Serial analysis of gene expression

Summary of SAGE. Within the organisms, genes are transcribed and spliced (in eukaryotes) to produce mature mRNA transcripts (red). The mRNA is extracted from the organism, and reverse transcriptase is used to copy the mRNA into stable double-stranded–cDNA (ds-cDNA; blue). In SAGE, the ds-cDNA is digested by restriction enzymes (at location 'X' and 'X'+11) to produce 11-nucleotide 'tag' fragments. These tags are concatenated and sequenced using long-read Sanger sequencing (different shades of blue indicate tags from different genes). The sequences are deconvoluted to find the frequency of each tag. The tag frequency can be used to report on transcription of the gene that the tag came from.[1]

Serial Analysis of Gene Expression (SAGE) is a transcriptomic technique used by molecular biologists to produce a snapshot of the messenger RNA population in a sample of interest in the form of small tags that correspond to fragments of those transcripts. Several variants have been developed since, most notably a more robust version, LongSAGE,[2] RL-SAGE[3] and the most recent SuperSAGE.[4] Many of these have improved the technique with the capture of longer tags, enabling more confident identification of a source gene.

  1. ^ Shafee, Thomas; Lowe, Rohan (2017). "Eukaryotic and prokaryotic gene structure". WikiJournal of Medicine. 4 (1). doi:10.15347/wjm/2017.002. ISSN 2002-4436.
  2. ^ Saha S, et al. (2002). "Using the transcriptome to annotate the genome". Nat Biotechnol. 20 (5): 508–12. doi:10.1038/nbt0502-508. PMID 11981567. S2CID 12709815.
  3. ^ Gowda M; Jantasuriyarat C; Dean RA; Wang GL. (2004). "Robust-LongSAGE (RL-SAGE): a substantially improved LongSAGE method for gene discovery and transcriptome analysis". Plant Physiol. 134 (3): 890–7. doi:10.1104/pp.103.034496. PMC 389912. PMID 15020752.
  4. ^ Matsumura H; Ito A; Saitoh H; Winter P; Kahl G; Reuter M; Krüger DH; Terauchi R. (2005). "SuperSAGE". Cell Microbiol. 7 (1): 11–8. doi:10.1111/j.1462-5822.2004.00478.x. PMID 15617519. S2CID 221579149.