The pituitary gland cell type enriched transcriptome

The pituitary gland is a small endocrine gland located at the base of the brain, with a crucial role in regulating many bodily functions. It consists of two main lobes: the anterior lobe, which produces and releases several important hormones such as growth hormone and thyroid-stimulating hormone, and the posterior lobe, which is highly enervated, and stores and releases hormones produced by the hypothalamus. Connected to the hypothalamus through blood vessels and nerve fibres, the pituitary gland forms part of the hypothalamic-pituitary axis, controlling various physiological processes such as growth, metabolism, reproduction, and stress response.

1522 genes were predicted to have cell type specificity in the pituitary gland.

12 cell types profiled
397 very highly enriched genes
380 highly enriched genes
745 moderately enriched genes

Pituitary gland cell type enriched transcriptome: Summary

Genes with predicted cell type specificity within pituitary gland are detailed in Table 1. Identified genes are subdivided into 3 specificity categories, based on the difference between the enrichment score in the corresponding cell type, compared to the other cell types profiled in the tissue (see Methods Summary page for details):

Predicted specificity: ´Very high´ - Differential score vs. other profiled cell types within the tissue >0.35
Predicted specificity: ´High´ - Differential score vs. other profiled cell types within the tissue >0.25
Predicted specificity: ´Moderate´ - Differential score vs. other profiled cell types within the tissue >0.15

Table 1. Number of genes in each specificity category in the pituitary gland cell types.

Cell type	Very high	High	Moderate	Total enriched
Somatotropes	94	36	12	142
Lactotropes	21	53	105	179
Gonadotropes	75	38	49	162
Corticotropes	93	76	77	246
Thyrotropes	12	35	60	107
Undifferentiated cells (Pituitary gland)	1	19	141	161
Endothelial cells	11	27	101	139
Fibroblasts	3	21	92	116
Macrophages	12	25	39	76
Neutrophils	7	10	12	29
T-cells	1	7	53	61
Plasma cells	67	33	4	104
All cell types	397	380	745	1522

Figure 1. Bar plot of the number of enriched genes in the cell types of the pituitary gland, divided by specificity category

Pituitary gland cell type enriched transcriptome: Illustrative examples

Corticotropes

Corticotropes make up about 20% of the anterior pituitary cells. These cells synthesize and release adrenocorticotropic hormone, cleaved from Pro-opiomelanocortin (POMC), which stimulates the adrenal cortex to produce cortisol and other steroid hormones. Other genes classified as having specificity in corticotropes included the neuropeptide galanin (GAL).

POMC - Pituitary gland
POMC
GAL - Pituitary gland
GAL

Gonadotropes

Gonadotropes secrete follicle-stimulating hormone (FSHB) and luteinizing hormone (LHB), which are essential for reproductive function.

FSHB - Pituitary gland
FSHB
LHB - Pituitary gland
LHB

Lactotropes

Lactotropes produce and release prolactin (PRL), which is important for milk production in mammals, and they express the transcription factor Pituitary-specific positive transcription factor 1 (POU1F1).

PRL - Pituitary gland
PRL
POU1F1 - Pituitary gland
POU1F1

Somatotropes

Somatotropes are the most abundant cell type in the anterior pituitary, comprising 30-50% of the gland. They produce and secrete growth hormone (GH1), which is crucial for regulating body growth and metabolism. Other genes classified as having specificity in somatotropes included Delta Like Non-Canonical Notch Ligand 1 (DLK1).

GH1 - Pituitary gland
GH1
DLK1 - Pituitary gland
DLK1

Thyrotropes

Thyrotropes constitute 3-5% of the anterior pituitary cells. They produce thyroid-stimulating hormone (TSHB), which regulates the function of the thyroid gland, and they express the transcription factor GATA Binding Protein 2 (GATA2).

TSHB - Pituitary gland
TSHB
GATA2 - Pituitary gland
GATA2