A Subset of Olfactory Sensory Neurons Express Forkhead Box J1-Driven eGFP

Abstract

Forkhead box protein J1 (FOXJ1), a member of the forkhead family transcription factors, is a transcriptional regulator of motile ciliogenesis. The nasal respiratory epithelium, but not olfactory epithelium, is lined with FOXJ1-expressing multiciliated epithelial cells with motile cilia. In a transgenic mouse where an enhanced green fluorescent protein (eGFP) transgene is driven by the human FOXJ1 promoter, robust eGFP expression is observed not only in the multiciliated cells of the respiratory epithelium but in a distinctive small subset of olfactory sensory neurons in the olfactory epithelium. These eGFP-positive cells lie at the extreme apical part of the neuronal layer and are most numerous in dorsal-medial regions of olfactory epithelium. Interestingly, we observed a corresponding small number of glomeruli in the olfactory bulb wherein eGFP-labeled axons terminate, suggesting that the population of eGFP+ receptor cells expresses a limited number of olfactory receptors. Similarly, a subset of vomeronasal sensory neurons expresses eGFP and is distributed throughout the full height of the vomeronasal sensory epithelium. In keeping with this broad distribution of labeled vomeronasal receptor cells, eGFP-labeled axons terminate in many glomeruli in both anterior and posterior portions of the accessory olfactory bulb. These findings suggest that Foxj1-driven eGFP marks a specific population of olfactory and vomeronasal sensory neurons, although neither receptor cell population possess motile cilia.

The role of motile cilia in the development and physiology of the nervous system

“…Olfactory cilia lack dynein arms in many species including humans [23], rodents [30] and zebrafish [22], and are therefore considered immotile. Yet, OSNs express the motile ciliary marker Foxj1 in mice [31,32] and olfactory placodes express foxj1b in zebrafish [33,34]. Strikingly, olfactory cilia were observed to be motile in frog [35] and trout [36].…”

Assessment of the effect of auditory integration therapy on human forkhead box protein J1 and its impact on behavioral, social, and sensory symptoms in children with autism spectrum disorder

“…Forkhead box protein J1 (Foxj1) is a member of the forkhead family transcription factors (Larson et al, 2019) associated with an extensive range of biological processes including DNA repair, cell cycle regulation, neurogenesis, and apoptosis (Genin et al, 2014). Foxj1 is associated with the production of motile cilia which are the main elements of ependymal cell differentiation and function in the central nervous system (CNS) (Spassky et al, 2005).…”