Glycoconjugate-specific developmental changes in the horse vomeronasal organ.

The study investigates the developmental changes in the glycoconjugate profile of a horse’s vomeronasal organ (VNO), a pheromone-sensing part of the olfactory system. Various techniques highlighted changes in both sensory and non-sensory epithelium cells, revealing potential influences on the organ’s function in adult horses.

Understanding the Vomeronasal Organ (VNO)

• The Vomeronasal Organ (VNO) is an essential part of most animals’ olfactory system; an organ that allows the sense of smell. It is specialized in detecting pheromones, chemical substances animals release to signal other individuals of the same species, impacting various aspects of their behavior including mating, territory marking, and social bonding.
• This cylindrical VNO includes sensory and non-sensory epithelia cells lining its lumen, with each type playing distinct roles in the functioning of the organ.

Procedure of the Study

• Scientists employed techniques like immunohistochemistry and lectin histochemistry to observe the developmental changes in a horse’s VNO, especially focusing on the glycoconjugate profile, a class of complex carbohydrates that are bonded to proteins or lipids.
• Immunostaining analysis revealed PGP9.5 protein expressions in some VNSE cells and vomeronasal receptor cells across different stages, from fetuses to adult horses. This protein is usually used as a marker to indicate the presence of nerve fibers and endocrine cells.
• Meanwhile, OMP (Olfactory Marker Protein) expression was found exclusively in receptor cells and was absent in VNSE, consistently, across fetuses, young foals, and adult horses.

Evaluating the Glycoconjugate Profile with Lectin Histochemistry

• To identify changes in the glycoconjugate content, scientists used lectin histochemistry, a method that employs specific proteins called lectins that can recognize and bind to particular sugar structures.
• With the application of 21 different lectins, semi-quantitative analysis revealed varying intensities of glycoconjugates labeled with these lectins. The most noticeable difference was between the young foals and adult horses’, indicating the higher presence of certain complex sugars in adults.
• These sugars (N-acetylglucosamine and galactose) are crucial for cellular communication processes, implying that their increased presence over the course of development may influence the functioning of the VNO in adult horses.