Prosaposin/Saposin Expression in the Developing Rat Olfactory and Vomeronasal Epithelia

Area of Science:

• Neuroscience
• Developmental Biology
• Molecular Biology

Background:

• Prosaposin, a glycoprotein, serves as a precursor for saposins or acts as a neurotrophic factor.
• Olfactory neuroepithelia (OE and VNE) exhibit lifelong neurogenesis, with mature neurons expressing prosaposin.
• The role of prosaposin during the development of the olfactory system is not fully understood.

Purpose of the Study:

• To investigate the expression pattern of prosaposin in the rat olfactory organ during postnatal development.
• To determine if prosaposin expression differs between the olfactory epithelium (OE) and vomeronasal epithelium (VNE) during development.
• To explore the potential role of prosaposin in the development of olfactory and vomeronasal receptor neurons.

Main Methods:

• Immunohistochemistry was used to detect prosaposin expression in rat olfactory organs.
• Olfactory marker protein (OMP) was used to identify mature olfactory receptor neurons (ORNs) and vomeronasal receptor neurons (VRNs).
• Prosaposin and OMP expression were examined from postnatal day 0 (P0) through postnatal day 20 (P20).

Main Results:

• In the OE, prosaposin immunoreactivity was detected in mature ORNs (OMP-positive) from P0.
• Immature ORNs in the OE did not show prosaposin immunoreactivity during the study period.
• In the VNE, prosaposin immunoreactivity was observed in VRNs from P0, including immature VRNs, while mature VRNs showed adult-like distribution from P20.

Conclusions:

• Prosaposin is expressed in both mature and immature neurons of the developing rat olfactory system, but with distinct patterns in the OE and VNE.
• The findings suggest that prosaposin may play different roles in the development of the OE and VNE.
• Further research is needed to elucidate the specific functions of prosaposin in olfactory and vomeronasal organ development.