| Data source |
SRA: PRJNA551501
|
| Description |
The thyroid gland is responsible for supplying the thyroid hormones to the body. The gland is an endocrine organ with an intricate structure enabling production, storage and release of the thyroid hormones. The gland is composed of numerous spherical follicles of varying sizes, surrounded by thyroid follicular epithelial cells, or thyrocytes. The thyrocytes surrounding the follicles generate the thyroid hormones in a multi-step process. Though the machinery responsible for the production of thyroid hormones by thyrocytes is well established, it remains unknown if all the thyrocytes resident in the thyroid gland are equally capable of generating thyroid hormones. In other words, the extent of molecular homogeneity between individual thyrocytes has not yet been investigated. To obtain an unbiased picture into the molecular heterogeneity present in zebrafish thyrocytes, we performed droplet based next-generation sequencing of individual thyrod gland cells. Using unsupervised clustering, we could identify all the major cell types present in the thyroid gland. Moreover, we could define sub-populations within the major cell-types, demonstrating the presence of molecular heterogeneity within nominally homogenous cell-populations. |
| Key word |
crispr; cas9; heterogeneity; single-cell; thyroid gland; zebrafish;rna-seq; expression; gene; proliferation; p63; follicles; protein; pax2.1; origin |
| Publication |
Gillotay, Pierre, et al. "Singleâ€cell transcriptome analysis reveals thyrocyte diversity in the zebrafish thyroid gland." EMBO reports 21.12 (2020): e50612. |
| Abstract |
The thyroid gland regulates growth and metabolism via production of thyroid hormone in follicles composed of thyrocytes. So far, thyrocytes have been assumed to be a homogenous population. To uncover heterogeneity in the thyrocyte population and molecularly characterize the non-thyrocyte cells surrounding the follicle, we developed a single-cell transcriptome atlas of the region containing the zebrafish thyroid gland. The 6249-cell atlas includes profiles of thyrocytes, blood vessels, lymphatic vessels, immune cells, and fibroblasts. Further, the thyrocytes show expression heterogeneity, including bimodal expression of the transcription factor pax2a. To validate thyrocyte heterogeneity, we generated a CRISPR/Cas9-based pax2a knock-in line that monitors pax2a expression in the thyrocytes. A population of pax2a-low mature thyrocytes interspersed in individual follicles can be distinguished. We corroborate heterogeneity within the thyrocyte population using RNA sequencing of pax2a-high and pax2a-low thyrocytes, which demonstrates 20% differential expression in transcriptome between the two subpopulations. Our results identify and validate transcriptional differences within the presumed homogenous thyrocyte population. |
