Loss of bhlha9 Impairs Thermotaxis and Formalin-Evoked Pain in a Sexually Dimorphic Manner.

C-LTMRs are known to convey affective aspects of touch and to modulate injury-induced pain in humans and mice. However, a role for these neurons in temperature sensation has been suggested, but not fully demonstrated. Here, we report that deletion of C-low-threshold mechanoreceptor (C-LTMR)-expressed bhlha9 causes impaired thermotaxis behavior and exacerbated formalin-evoked pain in male, but not female, mice.

Floor plate descendants in the ependyma of the adult mouse Central Nervous System.

During embryonic development of the Central Nervous System (CNS), the expression of the bHLH transcription factor Nato3 (Ferd3l) is unique and restricted to the floor plate of the neural tube. In mice lacking Nato3 the floor plate cells of the spinal cord do not fully mature, whereas in the midbrain floor plate, progenitors lose some neurogenic activity, giving rise to a reduced population of dopaminergic neurons. Since the floor plate is considered to be disintegrated at the time of birth, Nato3 expression was never tested postnatally and in adult mice.

Gene dosage of the transcription factor Fingerin (bHLHA9) affects digit development and links syndactyly to ectrodactyly.

Distal limb deformities are congenital malformations with phenotypic variability, genetic heterogeneity and complex inheritance. Among these, split-hand/foot malformation is an ectrodactyly with missing central fingers, yielding a lobster claw-like hand, which when combined with long-bone deficiency is defined as split-hand/foot malformation and long-bone deficiency (SHFLD) that is genetically heterogeneous. Copy number variation (CNV) consisting of 17p13.

Nato3 plays an integral role in dorsoventral patterning of the spinal cord by segregating floor plate/p3 fates via Nkx2.2 suppression and Foxa2 maintenance.

During embryogenesis, the dorsal roof plate and the ventral floor plate (FP) act as organizing centers to pattern the developing neural tube. Organizer-secreted morphogens provide signals that are interpreted via the graded expression of transcription factors. These factors establish a combinatorial code, which subsequently determines the fate of neuronal progenitors along the dorsoventral axis.

Nato3 integrates with the Shh-Foxa2 transcriptional network regulating the differentiation of midbrain dopaminergic neurons.

Mesencephalic dopaminergic (mesDA) neurons originate from the floor plate of the midbrain, a transient embryonic organizing center located at the ventral-most midline. Since the loss of mesDA leads to Parkinson's disease, the molecular mechanisms controlling the genesis and differentiation of dopaminergic progenitors are extensively studied and the identification and characterization of new genes is of interest. Here, we show that the expression of the basic helix-loop-helix transcription factor Nato3 (Ferd3l) increases in parallel to the differentiation of SN4741 dopaminergic cells in vitro.

Integrin-targeted nanoparticles for siRNA delivery.

Integrins are heterodimeric membrane glycoproteins composed of noncovalently associated α and β subunits. Integrins support cell attachment and migration on the surrounding extracellular matrix as well as mediate cell-cell interaction in physiological and pathological settings. Constant recycling of integrins from the plasma membrane to the endosome makes integrins ideal receptors for the delivery of drugs to the cell cytoplasm.

Foxa2 regulates the expression of Nato3 in the floor plate by a novel evolutionarily conserved promoter.

The development of the neural tube into a complex central nervous system involves morphological, cellular and molecular changes, all of which are tightly regulated. The floor plate (FP) is a critical organizing center located at the ventral-most midline of the neural tube. FP cells regulate dorsoventral patterning, differentiation and axon guidance by secreting morphogens.

The systemic toxicity of positively charged lipid nanoparticles and the role of Toll-like receptor 4 in immune activation.

Delivery of nucleic acids with positively charged lipid nanoparticles ((+)NPs) is widely used as research reagents and potentially for therapeutics due to their ability to deliver nucleic acids into the cell cytoplasm. However, in most reports little attention has been made to their toxic effects. In the present study, we performed comprehensive analyses of the potential toxicity associated with (+)NPs.

Math1 target genes are enriched with evolutionarily conserved clustered E-box binding sites.

The basic helix-loop-helix (bHLH) transcription factor Math1 and its orthologs are fundamental for proper development of various neuronal subpopulations, such as cerebellar granule cells, D1 interneurons in the spinal cord, and inner ear hair cells. Although crucial for neurogenesis, the mechanisms by which Math1 specifically recognizes its direct targets are not fully understood. To search for direct and indirect target genes and signaling pathways controlled by Math1, we analyzed the effect of Math1 knockout on the expression profile of multiple genes in the embryonic cerebellum.

A novel role for the choroid plexus in BMP-mediated inhibition of differentiation of cerebellar neural progenitors.

Cerebellar granule cells, the most abundant neurons in the mammalian brain, arise in the rhombic lip located at the roof of the brain's fourth ventricle. Bordering the rhombic lip is the choroid plexus, a non-neuronal structure, composed of blood vessels enveloped by epithelial cells. Here, we show a striking decrease in neural differentiation of rhombic lip-derived cells, which failed to extend neuritic processes and attenuate Math1 promoter activity, when co-cultured with choroid plexus cells.

BjalphaIT: a novel scorpion alpha-toxin selective for insects--unique pharmacological tool.

Long-chain neurotoxins derived from the venom of the Buthidae scorpions, which affect voltage-gated sodium channels (VGSCs) can be subdivided according to their toxicity to insects into insect-selective excitatory and depressant toxins (beta-toxins) and the alpha-like toxins which affect both mammals and insects. In the present study by the aid of reverse-phase HPLC column chromatography, RT-PCR, cloning and various toxicity assays, a new insect selective toxin designated as BjalphaIT was isolated from the venom of the Judean Black Scorpion (Buthotus judaicus), and its full primary sequence was determined: MNYLVVICFALLLMTVVESGRDAYIADNLNCAYTCGSNSYCNTECTKNGAVSGYCQWLGKYGNACWCINLPDKVPIRIPGACR (leader sequence is underlined). Despite its lack of toxicity to mammals and potent toxicity to insects, BjalphaIT reveals an amino acid sequence and an inferred spatial arrangement that is characteristic of the well-known scorpion alpha-toxins highly toxic to mammals.

Genotype identification of Math1/LacZ knockout mice based on real-time PCR with SYBR Green I dye.

Knockout mice are widely used in all fields of biomedical research. Determining the genotype of every newborn mouse is a tedious task, usually performed by Southern blot hybridization or Polymerase Chain Reaction (PCR). We describe here a quick and simple genotype identification assay based on real-time PCR and SYBR Green I dye, without using fluorescent primers.

Dual control of neurogenesis by PC3 through cell cycle inhibition and induction of Math1.

Growing evidence indicates that cell cycle arrest and neurogenesis are highly coordinated and interactive processes, governed by cell cycle genes and neural transcription factors. The gene PC3 (Tis21/BTG2) is expressed in the neuroblast throughout the neural tube and inhibits cell cycle progression at the G1 checkpoint by repressing cyclin D1 transcription. We generated inducible mouse models in which the expression of PC3 was upregulated in neuronal precursors of the neural tube and of the cerebellum.

Math1 controls cerebellar granule cell differentiation by regulating multiple components of the Notch signaling pathway.

Cerebellar granule cells (CGC) are the most abundant neurons in the mammalian brain, and an important tool for unraveling molecular mechanisms underlying neurogenesis. Math1 is a bHLH transcription activator that is essential for the genesis of CGC. To delineate the effects of Math1 on CGC differentiation, we generated and studied primary cultures of CGC progenitors from Math1/lacZ knockout mice.

Alternative splicing and neuritic mRNA translocation under long-term neuronal hypersensitivity.

To explore neuronal mechanisms underlying long-term consequences of stress, we studied stress-induced changes in the neuritic translocation of acetylcholinesterase (AChE) splice variants. Under normal conditions, we found the synaptic AChE-S mRNA and protein in neurites. Corticosterone, anticholinesterases, and forced swim, each facilitated a rapid (minutes), yet long-lasting (weeks), shift from AChE-S to the normally rare AChE-R mRNA, promoted AChE-R mRNA translocation into neurites, and induced enzyme secretion.

Nato3 is an evolutionarily conserved bHLH transcription factor expressed in the CNS of Drosophila and mouse.

The evolutionarily conserved basic helix-loop-helix (bHLH) transcription factors play important roles during development. Here we report the identification of Nato3 (nephew of atonal fer3) orthologs in Drosophila, C. elegans, mouse, and man, all of which share a high degree of similarity within the bHLH domain.

Autoregulation and multiple enhancers control Math1 expression in the developing nervous system.

Development of the vertebrate nervous system requires the actions of transcription factors that establish regional domains of gene expression, which results in the generation of diverse neuronal cell types. MATH1, a transcription factor of the bHLH class, is expressed during development of the nervous system in multiple neuronal domains, including the dorsal neural tube, the EGL of the cerebellum and the hair cells of the vestibular and auditory systems. MATH1 is essential for proper development of the granular layer of the cerebellum and the hair cells of the cochlear and vestibular systems, as shown in mice carrying a targeted disruption of Math1.

Functional conservation of atonal and Math1 in the CNS and PNS.

To determine the extent to which atonal and its mouse homolog Math1 exhibit functional conservation, we inserted (beta)-galactosidase (lacZ) into the Math1 locus and analyzed its expression, evaluated consequences of loss of Math1 function, and expressed Math1 in atonal mutant flies. lacZ under the control of Math1 regulatory elements duplicated the previously known expression pattern of Math1 in the CNS (i.e.

Math1: an essential gene for the generation of inner ear hair cells.

The mammalian inner ear contains the cochlea and vestibular organs, which are responsible for hearing and balance, respectively. The epithelia of these sensory organs contain hair cells that function as mechanoreceptors to transduce sound and head motion. The molecular mechanisms underlying hair cell development and differentiation are poorly understood.

Organization and evolution of olfactory receptor genes on human chromosome 11.

Olfactory receptors (OR) are encoded by a large multigene family including hundreds of members dispersed throughout the human genome. Cloning and mapping studies have determined that a large proportion of the olfactory receptor genes are located on human chromosomes 6, 11, and 17, as well as distributed on other chromosomes. In this paper, we describe and characterize the organization of olfactory receptor genes on human chromosome 11 by using degenerate PCR-based probes to screen chromosome 11-specific and whole genome clone libraries for members of the OR gene family.

Math1 is essential for genesis of cerebellar granule neurons.

The cerebellum is essential for fine motor control of movement and posture, and its dysfunction disrupts balance and impairs control of speech, limb and eye movements. The developing cerebellum consists mainly of three types of neuronal cells: granule cells in the external germinal layer, Purkinje cells, and neurons of the deep nuclei. The molecular mechanisms that underlie the specific determination and the differentiation of each of these neuronal subtypes are unknown.

Cerebellar deficient folia (cdf): a new mutation on mouse chromosome 6.

Cerebellar deficient folia, cdf, is a spontaneous autosomal recessive mutation in the mouse with unique pathology; the cerebellar cortex of the cdf/cdf mouse has only 7 folia instead of 10, which is the normal count for the C3H/HeJ strain in which this mutation arose. The cerebellum of the cdf/cdf mouse is hypoplastic and contains mineral deposits in the ventral vermis that are not present in controls. We used an intersubspecific intercross between C3H/HeSnJ-cdf/+ and Mus musculus castaneus (CAST/Ei) to map the cdf mutation to Chromosome (Chr) 6.

Evolutionary conservation of sequence and expression of the bHLH protein Atonal suggests a conserved role in neurogenesis.

atonal is a Drosophila proneural gene that belongs to the family of basic helix-loop-helix (bHLH)- containing proteins. It is expressed in the chordotonal organs and photoreceptor cells, and flies that lack Atonal protein are ataxic and blind. Here we report the cloning of atonal homologs from red flour beetle, puffer fish, chicken, mouse, and human.

Olfactory receptor gene cluster on human chromosome 17: possible duplication of an ancestral receptor repertoire.

A gene superfamily of olfactory receptors (ORs) has recently been identified in a number of species. These receptors share a seven transmembrane domain structure with many neurotransmitter and hormone receptors, and are likely to underlie the recognition and G-protein-mediated transduction of odorant signals. Previously, OR genes cloned in different species were from random locations in the respective genomes.