Morphology of the Uterotubal Junction of the Cheetah (Acinonyx jubatus)

Abstract

Less than 7,000 cheetahs survive in the wild. Captive breeding has proved notoriously difficult. The uterotubal junction acts as major barrier and regulator to the passage of sperm. This study describes the morphology of the uterotubal junction of the cheetah. Reproductive tracts were obtained from seven cheetahs that succumbed from natural causes or were euthanized for humane reasons. The uterotubal junction was isolated and examined macroscopically and microscopically. The extramural isthmus made a characteristic 90° bend before entering the mesometrial border of the uterus close to its tip. The intramural isthmus had approximately four primary folds lined by nonciliated cuboidal to low cuboidal epithelium. The Tunica muscularis was robust, merged with its uterine counterparts and consisted of an inner circular layer and outer longitudinal smooth muscle layer. The uterine ostium opened via a muscular and glandular papilla that projected from the apex of the uterine lumen. A sharply demarcated circular zone of simple columnar epithelial cells surrounded the uterine ostium and separated the simple cuboidal to low cuboidal cells of the isthmus and uterine epithelium from each other. Branched tubulo‐alveolar glands, some with dilated lumens, were present in the papilla and sometimes extended into the adjacent endometrium. These glands might act as sperm storage areas, and could easily be confused with cystic endometrial hyperplasia. Low transverse endometrial ridges surrounded the papilla and extended caudally for a short distance before disappearing. The uterine glands were lined by a simple cuboidal epithelium. Anat Rec, 302:1855–1864, 2019. © 2019 American Association for Anatomy

Distribution of uterine histological changes in aged captive cheetahs (Acinonyx jubatus)

“…Blood supply to and from the ovary and uterus of domestic cats is via the ovarian and uterine arteries and veins respectively; these vessels anastomose with each other in the region of the tip of the uterine horns (Aronsohn & Faggella, 1993), and blood supply in the cheetah appears similar (Penfold, 2019). Additionally, cheetahs have a prominent uterine tube blood vessel which anastomoses with the myometrial blood vessels in the tip of the uterine horn (Penfold et al, 2019). Higher plasma concentrations of ovarian‐derived hormones flow from the ovary, some travelling via the vessels into the uterine horns.…”

“…Our findings support examination of three sections obtained from the tip of the uterine horn as a screening method for detection of diffuse uterine changes in the cheetah. Due caution must be exercised when sampling this site to avoid accidental inclusion of the uterotubal junction with its papillary glands (Penfold et al, 2019) with a resultant erroneous diagnosis of CEH.…”

“…The 1‐mm section between each sample was discarded to prevent mirroring. The cranial third of the horn was sampled starting 5 mm caudal to the junction of the uterine horn with the uterine tube and extending caudally so as to avoid the uterotubal junction and its associated papillary glands (Penfold, Soley, & Hartman, 2019). The sections were routinely processed (Wolfe, 2019), embedded in paraffin and stained with hematoxylin and eosin.…”

Uterotubal Junction of the Bovine (Bos taurus) vs. the Dromedary Camel (Camelus dromedarius): Histological and Histomorphometry Analysis

“…The basic role, morphology, and description of UTJP are still unidenti ed in the camel. A microscopic papilla is present at the UTJ in cheetahs 9 . In the mare, the uterine tube opens into the uterine horn with the ostium forming a barrier against ascending infection 15 .…”

“…The oviduct is a bromuscular structure that connects the ovary to the uterus, it is elongated, and tubular 8 . The uterotubal junction (UTJ), which connects the uterine tube to the uterine horn, is the uterine part of the isthmus and/or the last few millimeters of the extramural isthmus, and the cranial tip of the uterine horn 9 . In mammals, the structure of both the oviduct and uterus showed great diversity in morphological and functional features 10 .…”