Targeted Sequencing of TIN2 transcripts

TIN2 is an important regulator of telomere length, and mutations in TINF2, the gene encoding TIN2, cause short telomere syndromes. To identify full-length transcripts from the TINF2 gene in human and mouse cells, we used a modified 3' RACE paired with PacBio sequencing. Whole cell RNA was reverse transcribed using oligo(dT20) with an adapter sequence, then TIN2 mRNA was specifically amplified using primers to the adapter sequence and to a unique sequence in exon 1. These amplicons were sequenced with PacBio sequencing to determine the splicing variants, and we were able to identify a novel isoform expressed in human but not mouse cells. This isoform may have been missed by previous sequencing approaches because it does not contain a novel splice junction but rather a unique pattern of spliced and retained introns.