Immunocytological study of the distribution of C-cells calcitonin in the thyroid gland of the normal adult gerbil.

The distribution of C-cells in the thyroid gland of the gerbil (Meriones inguiculatus) was studied on serial sections in the cranio-caudal direction. C-cells were visualized by immunofluorescence with an anti-calcitonin immune serum. A very heterogeneous distribution was found. C-cells first appear in the posterio-interior position. Then they progressively occupy the whole posterior part and finally are confined to the posterio-exterior position. No C-cells at all were detected in the upper and lower poles. According to the species, there is a wide variation in the relative distribution of C-cells in the thyroid gland. Our results add to the information available about the distribution of C-cells and its bearing on phylogenic evolution.