Mouse Thyroid Nanopore RNAseq

In the present work, we pull attention to a remarkable phenomenon of a perpetually and robustly upregulated gene, the thyroglobulin gene (Tg). The gene is expressed in the thyroid gland and, as it has been recently demonstrated, forms so called transcription loop easily observable with light microscopy. Using this feature, we show that Tg is expressed at a high level from the moment a thyroid cell acquires its identity and both of the alleles remain highly active over the entire cell life, i.e. depending on a species, for months or years. We demonstrate that the high upregulation is characteristic of thyroglobulin genes in all major vertebrate groups. We prove that Tg is not influenced by the organismal levels of T3/T4 hormones, does not oscillate round the clock and is expressed during both exocrine and endocrine phases of the thyrocyte activity. We conclude that the thyroglobulin gene represents a valuable model to study maintenance of a high transcriptional upregulation. Overall design: We performed RNA sequencing to investigate intron retention in Tg transcripts. For this three thyroid glands were isolated and mRNAs were analyzed using Nanopore sequencing.