Identification of the exon structure and four alternative transcripts of the thyroglobulin-encoding gene

The human thyroglobulin (hTg)-encoding gene is a single-copy gene of more than 300 kb and composed of at least 42 exons. After studying the 5' portion of the Tg cDNA (from nucleotides (nt) 1 to 842), we have previously suggested the existence of alternative splicing of the hTg pre-mRNA in human thyroid tissue. Here, we describe four alternative splicings in the central region of the hTg pre-mRNA between nt 3597 and 4653. We have deduced from these results the exonic structure of this region (exons 16 to 22). Finally, the identification of alternative splicings has also allowed us to demonstrate the existence of a strong 5' splice site inside intron 16 of Tg.