PT  - JOURNAL ARTICLE
AU  - Diana V. Hunter
AU  - Brittney D. Smaila
AU  - Douglas M. Lopes
AU  - Jun Takatoh
AU  - Franziska Denk
AU  - Matt S. Ramer
TI  - Advillin is expressed in all adult neural crest-derived neurons
AID  - 10.1523/ENEURO.0077-18.2018
DP  - 2018 Sep 10
TA  - eneuro
PG  - ENEURO.0077-18.2018
4099  - http://www.eneuro.org/content/early/2018/09/10/ENEURO.0077-18.2018.short
4100  - http://www.eneuro.org/content/early/2018/09/10/ENEURO.0077-18.2018.full
AB  - Promoter-based genetic recombination (via e.g. Cre-lox) is most useful when all cells of interest express a particular gene. The discovery that the actin-binding protein advillin is expressed in all somatic sensory neurons has been exploited repeatedly to drive DNA recombination therein, yet specificity of expression has not been well-demonstrated. Here we characterize advillin expression amongst sensory neurons, and in several other neural and non-neural tissues. We first validate an advillin antibody against advillin knockout tissue, advillin promoter-driven EGFP and advillin mRNA expression. In the dorsal root ganglion, advillin is enriched in non-peptidergic nociceptors. We also show that advillin expression, and advillin promotor-driven EGFP and Cre-recombinase expression, occurs in multiple tissues including the dorsal habenula of the epithalamus, endocrine cells of the gut, Merkel cells in the skin, and most strikingly, throughout the autonomic nervous system (sympathetic, parasympathetic, and enteric neurons) in mice, rats, and non-human primates. In the mouse pelvic ganglion, advillin immunoreactivity is most intense in pairs of small neurons, and concentrated in spine-like structures on the axon initial segment contacted by sympathetic preganglionic axons. In autonomic targets (iris and blood vessels), advillin is distributed along cholinergic parasympathetic axons and in sympathetic varicosities. Developmentally, advillin expression is absent from sympathetics at post-natal day 4, but begins to emerge by day 7, accounting for previous reports (based on embryonic expression) of advillin’s specificity to sensory neurons. These results indicate that caution is warranted in interpreting previous studies in which advillin-driven genomic editing is either constitutive or performed after post-natal day 4.Significance Statement Cell-specific promoters are useful for effecting DNA recombination (e.g. via Cre-lox) for studies of lineage and gene function. Accordingly, advillin, an actin-binding protein expressed in all somatic sensory neurons, has proven valuable in manipulating gene expression therein. Whether advillin expression is restricted to sensory neurons, which is crucial to ascribing primary afferent-specific roles of particular genes, has not been established. Here we show that advillin is also expressed throughout the adult autonomic and enteric nervous systems, the habenula, and endocrine cells of the skin and gut. Thus, while advillin promoter activity remains useful in achieving recombination in sensory neurons (and some other cells), caution is warranted in interpreting results of experiments in which outcomes depend on multiple advillin-expressing tissues.