Rtfc (4931414P19Rik) Regulates in vitro Thyroid Differentiation and in vivo Thyroid Function.

Thyroid is a one of the most important endocrine organs. Understanding the molecular mechanism underlying thyroid development and function, as well as thyroid diseases, is beneficial for the clinical treatment of thyroid diseases and tumors. Through genetic linkage analysis and exome sequencing, we previously identified an uncharacterized gene C14orf93 (RTFC, mouse homolog: 4931414P19Rik) as a novel susceptibility gene for familial non-medullary thyroid carcinoma, and demonstrated its function in promoting thyroid tumor. However, the role of RTFC in thyroid development and function remains unexplored. In this study, we found that knockout of Rtfc compromises the in vitro thyroid differentiation of mouse embryonic stem cells. In contrast, Rtfc-/- mice are viable and fertile, and the size and the morphology of thyroid are not affected by Rtfc knockout. However, female Rtfc-/- mice, but not male Rtfc-/- mice, display mild hypothyroidism. In summary, our data suggest the roles of Rtfc in in vitro thyroid differentiation of embryonic stem cells, and in vivo thyroid function.