After allowing the?slides to cool, they were washed once in TBS, endogenous peroxidases were blocked in 0.1% hydrogen peroxide for 10 min, followed by three 1 TBS washes. the loss of Alfy in mice disrupts localization of glial guidepost cells, and attenuates axon outgrowth in response to Netrin-1. These findings further BAF312 (Siponimod) support the growing indication that macroautophagy plays a key role in the developing CNS. DOI: http://dx.doi.org/10.7554/eLife.14810.001 is nearly identical to the gene that encodes the Alfy protein, and has been implicated in neurodevelopmental disorders such as autism and microencephaly. Studying Alfy therefore may help us to understand human conditions that affect the developing or aging brain. DOI: http://dx.doi.org/10.7554/eLife.14810.002 Introduction The Autophagy linked FYVE domain protein (Alfy) [gene name, WD40 repeat and FYVE domain protein 3 (is evolutionarily conserved and the most extensively studied homolog is in (Finley et al., 2003). In the developing and adult fly central nervous system (CNS), Bchs is abundantly expressed, with preferential accumulation in axon terminals and at the growth cone (Finley et al., 2003; Khodosh et al., 2006). Adult null flies have a shortened life span and show signs of adult onset neurodegeneration, including the accumulation of ubiquitinated aggregates (Filimonenko et al., Mouse monoclonal to SCGB2A2 2010; Finley et al., 2003; Khodosh et al., 2006). Loss-of-function (LoF) mutations in disrupt the BAF312 (Siponimod) axonal transport of endolysosomal vesicles (Lim and Kraut, 2009), however no defects in axon guidance have been reported in null larva (Khodosh et al., 2006). Recently it has been reported that in vertebrates, genetically diminished levels of Alfy disrupts neurogenesis leading to altered forebrain morphology (Orosco et al., 2014). Furthermore, genetic screening has revealed a possible role for the human homolog as a genetic risk factor for intellectual and developmental disabilities (IDD), microcephaly and neuropsychiatric disorders (Bonnet et al., 2010; Iossifov et al., 2012; Kadir et al., 2016). These findings raise the possibility that Alfy could have an important function in mammalian?CNS?development. Here, we present two new mouse models that eliminate Alfy expression and identify an essential role for Alfy during murine development. Constitutive elimination of Alfy leads to perinatal lethality, in conjunction with developmental brain wiring defects throughout the CNS, involving forebrain commissures, internal capsule, optic chiasm, spinal cord and longitudinal tracts such as the medial forebrain bundle. In the ventral midbrain, dopaminergic cell populations retain an immature morphology and their axons aberrantly project into the hypothalamic region, forming an ectopic commissure near the optic chiasm. Consistent with a failure of axon guidance mechanisms, localization of glial guidepost cells for callosal axons were disrupted, and sensitivity of Alfy knockout axons to the trophic effect of Netrin-1 was significantly diminished. Moreover, Alfy is enriched in membrane fractions, suggesting that it may play a key role in membrane trafficking events to establish neural connectivity in the mammalian brain. Results Alfy is highly expressed in the CNS To characterize the role of Alfy in mouse, we initially determined when and where Alfy/Wdfy3 is expressed. Multiplex, semi-quantitative RT-PCR revealed that mRNA could be detected as early as embryonic day (E) 11 in CNS tissue, and remains detectable throughout gestation (Figure 1A). Similar analysis in adult tissue revealed that the transcript is ubiquitously expressed, and?that?the highest concentration of Alfy was observed in the brain (Figure 1figure supplement 1), confirming previous results (Simonsen et al., 2004). transcript is detected throughout the both the perinatal and adult brain, as determined by hybridization (ISH) (Figure 1B and not shown). Immunoblotting revealed that expression of the protein was present uniformly throughout the brain (Figure 1C). Using both primary neuronal and purified astroglial cultures, endogenous Alfy expression was detected in both cell types (Figure 1figure supplement 2), supporting recent transcriptome analysis of the mouse cortex (Zhang et al., BAF312 (Siponimod) 2014). Therefore, we conclude that Alfy is a CNS-enriched protein that is present in various neuronal and non-neuronal cell types in the developing and adult brain. Open in a separate window Figure 1. Alfy is highly expressed throughout the developing and adult mouse CNS.(A) (Top) RT-PCR demonstrates Alfy/Wdfy3.
Categories