Genome wide expression profiling of the mesodiencephalic region identifies novel factors involved in early and late dopaminergic development

Abstract

SummaryMeso-diencephalic dopaminergic (mdDA) neurons are critical for motor control and cognitive functioning and their loss or dysfunction is associated with disorders such as Parkinson's disease (PD), schizophrenia and addiction. However, relatively little is known about the molecular mechanisms underlying mdDA neuron development and maintenance. Here, we determined the spatiotemporal map of genes involved in the development of mdDA neurons to gain further insight into their molecular programming. Genome-wide gene expression profiles of the developing ventral mesencephalon (VM) were compared at different developmental stages leading to the identification of novel regulatory roles of neuronal signaling through nicotinic acthylcholine receptors (Chrna6 and Chrnb3 subunits) and the identification of novel transcription factors (Oc2 and 3) involved in the generation of the mdDA neuronal field. We show here that Pitx3, in cooperation with Nurr1, is the critical component in the activation of the Chrna6 and Chrnb3 subunits in mdDA neurons. Furthermore, we provide evidence of two divergent regulatory pathways resulting in the expression of Chrna6 and Chrnb3 respectively.

Frizzled3 Controls Axonal Polarity and Intermediate Target Entry during Striatal Pathway Development

“…Wnt5a knockout mice (Yamaguchi et al, 1999) and ROSA26-DTA mice (Ivanova et al, 2005) were obtained from The Jackson Laboratory, and Drd2-EGFP, Chrm4-EGFP, and Drd2-Cre (ER44) BAC transgenic mice from Mutant Mouse Regional Resource Center (www.gensat.org) (Gong et al, 2003(Gong et al, , 2007. Frizzled3 fl/fl mice were as described previously (Chai et al, 2014). The morning of detection of the vaginal plug was defined as embryonic (E) day 0.5, and the day of birth as postnatal (P) day 0.…”

“…Each experimental sample consisted of pooled RNA derived from at least two hemizygous D2-EGFP or M4-EGFP embryos. cDNA synthesis, cRNA double amplification, and quality control and fragmentation were performed using an automated system (Caliper Life Sciences) and starting with 70 ng total RNA from each sample, as described previously (Chakrabarty et al, 2012). The qPCR was performed in a 10 l reaction solution using Roche SYBR Green I (LC-FastStart DNA MasterPlus) and 0.5 M of each primer.…”

“…For quantification of corridor-striatal explant cocultures, the length of the 40 longest axons extending into the quadrants proximal and distal to the corridor explant was measured with ImageJ software. Once the mean P/D ratio of each explant was determined, a guidance index was calculated as described previously (Bielle et al, 2011b). Data were statistically analyzed by unpaired two-tailed Mann-Whitney test, one-way ANOVA (␣ ϭ 5%) or Kruskal-Wallis test and expressed as mean Ϯ SEM.…”

“…10 N, O). Corridor cells express repulsive axon guidance proteins, such as Slit1, ephrinA5, and class 3 semaphorins (Sema3s), that guide thalamocortical axons in the subpallium (Garel and Ló pez-Bendito, 2014). The ectopic expression of these cues in the GP, due to mislocalization of corridor cells, could counteract the normally attractive effect of the GP on MSN axons.…”

Onecut transcription factors act upstream of Isl1 to regulate spinal motoneuron diversification

“…These proteins are detected during development in several endodermal derivatives including liver and pancreas, where they redundantly control different aspects of cell fate decision and morphogenetic processes (Jacquemin et al, 2000;Clotman et al, 2002;Jacquemin et al, 2003a;Pierreux et al, 2006;Vanhorenbeeck et al, 2007). They are also present in the embryonic CNS (Landry et al, 1997;Jacquemin et al, 2003b;Vanhorenbeeck et al, 2007), where they regulate the generation, maintenance or the projections of different encephalic structures (Hodge et al, 2007;Chakrabarty et al, 2012;Espana and Clotman, 2012a;Espana and Clotman, 2012b) and of a spinal interneuron population (Stam et al, 2012). In the ventral spinal cord, the three OC genes are differentially and dynamically expressed during the early steps of MN differentiation (Francius and Clotman, 2010), suggesting that OC factors might contribute to spinal MN development.…”