The mouse prostate: a basic anatomical and histological guideline

Abstract

Despite substantial similarities in embryological, cellular and molecular biology features, human and mouse prostates differ in organ morphology and tissue architecture. Thus, a clear understanding of the anatomy and histology of the mouse prostate is essential for the identification of urogenital phenotypes in genetically engineered mice, as well as for the study of the etiology, development, and treatment of human prostatic diseases for which mouse models are used. The purpose of this manuscript is to provide a brief guide for the dissection of the mouse prostate and the identification of its different lobes and histology, to both basic researchers and medical pathologists who are unfamiliar with mouse tissues.

FIGURE 1

Mouse dissection and excision of the male urogenital tract. (A) Adult male mouse in supine position. Dashed lines indicate the skin incision pattern to follow; (B) Bladder (below cotton swab) and seminal vesicles (arrow) are easily identified once the abdominal cavity of the mouse is opened; (C) Most of the urogenital tract can be harvested from the mouse carcass en bloc by grasping the bladder with tweezers, pulling it up, and cutting the base of the urethra (arrowhead). Scale bar, 0.5 cm.

FIGURE 2

Gross view of mouse male urogenital organs. (A) Anterior and (C) posterior aspects of the urogenital tract dissected from an adult male mouse, as seen under the dissecting microscope. Urethra (U), Seminal vesicles (SV); (B) and (D) show the same images with dashed and dotted lines delineating the ventral (VP), lateral (LP), anterior (AP), and dorsal (DP) prostate lobes; (E) Anterolateral view (left side) of the prostate lobes relative to the bladder, seminal vesicles, and urethra (Modified from: Sugimura, Y., et al. [15]). Scale bar, 1 cm.

FIGURE 3

Cross section of a normal urogenital tract from an adult male mouse. (A) Adjacent to the prostate lobes here can be seen the urethra and a vas deferens, both surrounded by thick muscular walls, and a seminal vesicle with characteristic large lumen filled with strong esosinophilic secretion; (B) The different prostate lobes have been highlighted in orange (VP), light blue (LP), green (DP), and grey (AP), for proper identification. Hematoxylin and eosin, 25X.

FIGURE 4

Mouse prostate lobes. Representative images are shown. (A) Ventral prostate: moderate to large acini are lined by cuboidal to simple columnar epithelium with flat luminal borders. Note the basally located nuclei (arrowheads) and the tufting pattern (arrows). A pale serous secretion is a unique characteristic of the ventral prostate lobe; (B) Dorsal Prostate: small acini are mostly line by simple columnar epithelium with centrally located nuclei (arrowhead) and sparse infoldings (arrow). A dense stroma (*) surrounding the acini is typical. An eosinophilic secretion is typically seen in the acini; (C) Lateral prostate: small to large acini are lined by cuboidal to low columnar epithelium with nuclei located basally (arrowhead) that form sparse infoldings (arrow). Similar to the ventral prostate, acini from the lateral prostate have a flat luminal border; (D) Anterior prostate: moderate to large acini lined mostly by cuboidal to columnar epithelium with nuclei located centrally (arrowhead) and with infoldings (arrows). Abundant eosinophilic luminal secretion is characteristic, along with the presence of noticeable smooth muscle (*) surrounding each acinus. Hematoxylin and eosin. Scale bar, 100 µm.

FIGURE 5

Identification of mouse prostate lobes. This decision tree suggests some key points that the basic researcher or pathologist may use to identify the different mouse prostate lobes in hematoxylin and eosin stained sections of the male mouse genitourinary tract.