Histological study on the prenatal development of compartment 1 of the stomach of the camel (Camelus dromedarius).

Abstract

Background: The largest portion of the dromedary camel's stomach, known as Compartment 1, plays a vital role in the microbial fermentation of ingested food.

Aim: This study aimed to investigate the prenatal development of Compartment 1 in camel fetuses during the three gestational trimesters.

Methods: Stomach samples were collected from 21 healthy camel fetuses of both sexes at various gestational ages (79-390 days). The samples were fixed in 10% buffered formalin and histologically examined.

Results: The primitive stomach wall consisted of three layers in the early first trimester (79 days): epithelial, pluripotent blastemic tissue, and myoblastic. By 87-115 days, the wall displayed smooth to undulating surface regions and comprised four layers: epithelium, lamina propria-submucosa, tunica muscularis, and serosa. At 120-128 days, the smooth surface region of Compartment 1 was lined with stratified epithelium comprising a basal layer of cuboidal cells and 2-3 layers of lightly stained polyhedral cells. In contrast, the undulating surface was lined with pseudostratified columnar epithelium. During the second trimester (163-234 days), the smooth surface region differentiated into a non-glandular zone composed of three layers: stratum basale, spinosum, and granulosum. The folded surface developed into a glandular region characterized by multiple folds and deep pits forming chamber-like structures. These folds exhibited distinct epithelial linings: stratified epithelium at the apices, pseudostratified epithelium on the lateral sides, and simple columnar epithelium in the chambers. In the third trimester (270-390 days), a superficial layer of squamous cells forming the stratum corneum appeared above the three epithelial strata in the non-glandular region. Additionally, the glandular region's lamina propria contained simple tubular glands lined by simple columnar epithelium.

Conclusion: Compartment 1 of the dromedary camel undergoes marked histological differentiation throughout gestation, evolving from a simple three-layered wall to a highly specialized organ. Notably, the apical folds develop lateral vertical projections in the glandular region where the stratified epithelium transitions into the pseudostratified epithelium, demonstrating regional specialization and functional differentiation.