The phrase "a transcript start" is not standard in written English and may cause confusion.
It could be used in contexts related to the beginning of a transcript, but it lacks clarity and specificity.
Example: "At the transcript start, the speaker introduced the main topic of discussion."
Alternatives: "the beginning of the transcript" or "the start of the transcript".
Variants are associated with transcripts if they are located within transcript or intron sequences, within 5 KB of a transcript start or end, or if they are located within a regulatory region associated with a gene or transcript.
Besides using a chosen cut-off for the increase in the number of read starts relative to the preceding position for calling a transcript start, the 5′-ends were validated by promoter searches, and from these validated 5′-ends, 3′-ends of transcripts were determined by another chosen cut-off of ten reads.
These data confirm the existence of a transcript starting in c-fos first intron in vivo, in tissues consistent with the transgenic analysis.
Thus a transcript starting with exon 7b, ending in intron 18, containing exon 9 and splicing E10-E11b-E14 would be called 'α-dystrobrevin-5b+'. Cloned products were used to generate dilution series as standards for quantitative nested RT-PCR.
Many of the 469 candidate STEPs not reported to have EST evidence of alternative splicing may exhibit an effect leading to an upstream transcript start (where an upstream exon is added by activation of an upstream splice site), intron extension (by activation of a weaker splice site in the adjacent exon) or exon skipping.
However, our RACE data did not identify a heterogeneous transcript start site.
However, a SyR2 transcript start was mapped within apcC, 49 nt before the end of the reading frame.
The number of candidate STEPs near exons causing an upstream transcript start (UTS) is an interesting result, perhaps illustrating that the common scenario of alternative splicing in 5' untranslated sequences results in an alternative first exon and not so commonly the activation of a cryptic splice site [21] or exon skipping.
Our results indicate the existence of at least two unique isoforms of NEAT1: a widely expressed, abundant 4 kb transcript and a much larger (> 17 kb), less common transcript sharing a transcriptional start site, based on 5'-RLM-RACE and Northern analysis.
Analysis of these lists revealed that many of the genes regulated by SYT-SSX1 expression in hMSCs belong to a restricted set of categories (table 1) that include imprinted genes, genes that encode for chromatin associated proteins, and genes having at least one transcript with a transcription start site (TSS) within a CpG island.
These different amplicons allow for comparison of the three distinct stages leading to a mature transcript starting from the genome, to a transcript without a trans-spliced leader, to a spliced transcript ready for translation.
