<Emphasis Type="Italic">DAT1</Emphasis> and <Emphasis Type="Italic">DRD4</Emphasis> genes involved in key dimensions of adult ADHD

Attention-deficit hyperactivity disorder (ADHD) is a highly heritable neurodevelopmental disorder often persisting in adulthood. Genetic studies of ADHD mainly focused on the Dopamine Transporter (DAT1) and the Dopamine Receptor 4 (DRD4) genes. Nevertheless, polymorphisms of these genes explain only a small fraction of the assigned risk, suggesting that intermediate dimensions and environmental factors should also be considered. We investigated in 77 adult ADHD subjects compared to 474 controls, how polymorphisms within the genes coding for DAT1 (40-bp VNTR in 3′UTR), the Dopamine Receptor 2 (DRD2) (rs1799732) and DRD4 (48-bp VNTR in exon 3), may modulate the expression of the disorder. By genotyping DAT1, we detected a new 9.5R allele showing a deletion of 40 bp and also an insertion of 19 bp compared to the 10R allele. This novel allele was found to be significantly protective for ADHD (p < 0.0001). Another significant difference was found in the distribution of DRD4 48-bp VNTR 6R allele when comparing patients and controls (p = 0.0007). In addition significant results were also found for DAT1 9.5R allele, which was associated with impulsiveness (p = 1.98 × 10^?4) and trait anger scores (p = 7.66 × 10^?4). Moreover, impulsiveness scores were partly modulated by an interaction between the DRD4 48-bp VNTR 6R allele and childhood maltreatment (p = 0.01), however, this result did not resist correction for multiple comparisons. Altogether, our results show the putative involvement of DAT1 and DRD4 genes in the aetiology of ADHD with a main role in modulation of key dimensions of the disorder.     

The complete mitochondrial genomes of two globally invasive ants,the Argentine ant <Emphasis Type="Italic">Linepithema</Emphasis><Emphasis Type="Italic">humile</Emphasis> and the little fire ant <Emphasis Type="Italic">Wasmannia auropunctata</Emphasis>

Ants are among the most widespread and damaging of invasive alien species. Here, we report the complete mitochondrial genomes for two globally invasive ants: the Argentine ant Linepithema humile and the little fire ant Wasmannia auropunctata. The circular genomes of L. humile and W. auropunctata are 15,929 and 16,362 bp in length, respectively, and encode the same typical set of 37 mitochondrial genes (i.e. 13 PCGs, 22 tRNAs and two rRNAs) and one control region. The mitochondrial genome of W. auropunctata harbors a unique gene arrangement (‘rrnS-trnV-CR-trnM-trnI-trnQ-nad2-trnW-trnC-trnY’; the underlines indicate inverted genes) between rrnL and cox1. Phylogenetic analysis largely corroborated the traditional taxonomy, except for L. humile which was found to be more related to those taxa of the subfamilies Formicinae and Myrmicinae than to the consubfamilial Leptomyrmex pallens. Our genomic data can be readily used for genetic assays of these two globally invasive ants.     

Association of <Emphasis Type="Italic">CILP</Emphasis>, <Emphasis Type="Italic">COL9A2</Emphasis> and <Emphasis Type="Italic">MMP3</Emphasis> Gene Polymorphisms with Lumbar Disc Degeneration in an Indian Population

Lumbar disc degeneration (LDD) is a multifactorial disorder caused by genetic and environmental factors. Polymorphisms in several structural and inflammatory genes like collagens, aggrecan, matrix metalloproteinases are associated with the risk of disc degeneration. In this study, we analyzed the role of a few important single nucleotide polymorphisms in cartilage intermediate layer protein (CILP), collagen 9A2 (COL9A2) and matrix metalloproteinase 3 (MMP3) genes in LDD from an Indian population. Two hundred patients with LDD and 200 healthy controls were recruited for the study. Genotyping was performed by allelic discrimination assay. The rs2073711 polymorphism (CILP gene - GG genotype) was associated with reduced risk of LDD in the Indian population (OR?=?0.43, p?=?0.016). The rs591058 polymorphism (MMP3 gene - TT genotype) is found to be associated with lower risk among women (OR?=?0.34, p?=?0.041). No significant association was found between COL9A2 polymorphism rs7533552 and the risk of LDD. We conclude that the CILP gene polymorphism (rs2073711) is associated with a lower risk of LDD, the MMP3 (rs591058) gene polymorphism is associated with LDD among women, and the TT genotype confers a lower risk of LDD.     

Climbing Fiber Development Is Impaired in Postnatal <Emphasis Type="Italic">Car8</Emphasis><Superscript><Emphasis Type="Italic">wdl</Emphasis></Superscript> Mice

The cerebellum is critical for an array of motor functions. During postnatal development, the Purkinje cells (PCs) guide afferent topography to establish the final circuit. Perturbing PC morphogenesis or activity during development can result in climbing fiber (CF) multi-innervation or mis-patterning. Structural defects during circuit formation typically have long-term effects on behavior as they contribute to the phenotype of movement disorders such as cerebellar ataxia. The Car8 ^wdl mouse is one model in which early circuit destruction influences movement. However, although the loss of Car8 leads to the mis-wiring of afferent maps and abnormal PC firing, adult PC morphology is largely intact and there is no neurodegeneration. Here, we sought to uncover how defects in afferent connectivity arise in Car8 ^wdl mutants to resolve how functional deficits persist in motor diseases with subtle neuropathology. To address this problem, we analyzed CF development during the first 3 weeks of life. By immunolabeling CF terminals with VGLUT2, we found evidence of premature CF synapse elimination and delayed translocation from PC somata at postnatal day (P) 10 in Car8 ^wdl mice. Surprisingly, by P15, the wiring normalized, suggesting that CAR8 regulates the early but not the late stages of CF development. The data support the hypothesis of a defined sequence of events for cerebellar circuits to establish function.     

Mutations in <Emphasis Type="Italic">dock1</Emphasis> disrupt early Schwann cell development

Background

In the peripheral nervous system (PNS), specialized glial cells called Schwann cells produce myelin, a lipid-rich insulating sheath that surrounds axons and promotes rapid action potential propagation. During development, Schwann cells must undergo extensive cytoskeletal rearrangements in order to become mature, myelinating Schwann cells. The intracellular mechanisms that drive Schwann cell development, myelination, and accompanying cell shape changes are poorly understood.

Methods

Through a forward genetic screen in zebrafish, we identified a mutation in the atypical guanine nucleotide exchange factor, dock1, that results in decreased myelination of peripheral axons. Rescue experiments and complementation tests with newly engineered alleles confirmed that mutations in dock1 cause defects in myelination of the PNS. Whole mount in situ hybridization, transmission electron microscopy, and live imaging were used to fully define mutant phenotypes.

Results

We show that Schwann cells in dock1 mutants can appropriately migrate and are not decreased in number, but exhibit delayed radial sorting and decreased myelination during early stages of development.

Conclusions

Together, our results demonstrate that mutations in dock1 result in defects in Schwann cell development and myelination. Specifically, loss of dock1 delays radial sorting and myelination of peripheral axons in zebrafish.

     

The complete chloroplast genome sequence of <Emphasis Type="Italic">Sophora japonica</Emphasis> var. <Emphasis Type="Italic">violacea</Emphasis>: gene organization and genomic resources

Sophora japonica var. violacea is an important ornamental plant, but its wild populations are now in danger, and need urgent conservation. In the present study, we sequenced the complete chloroplast genome of S. japonica var. violacea and used these data to assess genomic resources. The S. japonica var. violacea chloroplast genome is 158,837 bp in length, and includes a pair of inverted repeats of 25,398 bp that are separated by small and large single copy regions of 19,058 and 88,983 bp, respectively. The chloroplast genome of S. japonica var. violacea encodes 112 different genes, including 78 protein-coding genes, 30 transfer RNAs (tRNA) and 4 ribosomal RNAs (rRNA). We identified a total of 171 simple sequence repeat markers in the chloroplast genome. A phylogenetic tree constructed based on 78 protein-coding genes of 42 angiosperms showed that the position of S. japonica var. violacea is on the base of Papilionoideae. Overall, the results of this study will contribute to better support of the evolution, molecular biology and genetic improvement of S. japonica var. violacea.     

<Emphasis Type="Italic">ZNF804A</Emphasis> rs1344706 interacts with <Emphasis Type="Italic">COMT</Emphasis> rs4680 to affect prefrontal volume in healthy adults

The biological function of ZNF804A rs1344706, the first genome-wide supported risk variant of schizophrenia, remains largely unknown. Based on the upregulating effect of ZNF804A on the expression of COMT, we hypothesize that ZNF804A may affect grey matter volume (GMV) by interacting with COMT. Voxel-based morphometry was applied to analyze the main and interaction effects of ZNF804A rs1344706 and COMT rs4680 on brain GMV in 274 healthy young human subjects. The GMV of the left dorsolateral prefrontal cortex (DLPFC) showed a significant COMT rs4680 × ZNF804A rs1344706 interaction, manifesting as an inverted U-shape modulation by the presumed dopamine signaling. In COMT Met-allele carriers, the ZNF804A TG heterozygotes showed greater GMV in the left DLPFC than both GG and TT homozygotes. In COMT Val/Val homozygotes, however, the ZNF804A TG heterozygotes exhibited smaller GMV in the left DLPFC than GG homozygotes and comparable GMV with TT homozygotes. These findings suggest that ZNF804A affects the GMV of the prefrontal cortex by interacting with COMT, which may improve our understanding of neurobiological effect of ZNF804A and its association with schizophrenia.     

<Emphasis Type="Italic">Clostridium septicum</Emphasis> Pneumocephalus

Background

Spontaneous pneumocephalus in the nontraumatic setting is distinctly unusual. Pneumocephalus from central nervous system infection with Clostridium septicum has been rarely reported, and more commonly reflects a later stage of abscess formation. We present an unusual case of invasive C. septicum infection without an associated diagnosed malignancy presenting with rapidly progressive CNS pathology and resultant early pneumocephalus.

Methods

Medical records, radiologic imaging, and microbiological specimens of a case were reviewed.

Results

A 66-year-old male presented with a history of two witnessed generalized tonic–clonic seizures on awakening. He was found unresponsive at the scene by paramedics and subsequently intubated. There was no reported antecedent symptomatology, such as headache, fever, chills, focal weakness, and speech or gait disturbances. Medical history was remarkable only for diet-controlled hypertension. Computed tomography (CT) head imaging revealed an abnormal right parietal hypodensity. The patient was evaluated per the acute stroke protocol but was not deemed a candidate for intervention or thrombolytic therapy given the uncertainty of his clinical presentation; intravenous antibiotics were administered for possible sepsis. Follow-up CT imaging of the head performed 8 h later revealed right parieto-temporal pneumocephalus with extensive cerebral edema and effacement of basilar cisterns. Neurosurgical intervention was not deemed appropriate given the catastrophic nature of his injury and the patient subsequently expired 14 h after presentation. Blood cultures grew gram-positive rods in three of four bottles identified as C. septicum.

Conclusions

Clostridium septicum is an uncommon and often fatal cause of nontraumatic pneumocephalus. This underscores the need for a high index of clinical suspicion in cases with unexplained pneumocephalus, as early diagnosis remains the key to survival. In survivors of C. septicum infection, subsequent colonoscopy should be considered to exclude undiagnosed or occult gastrointestinal malignancy.

     

Coexistence of <Emphasis Type="Italic">CLCN1</Emphasis> and <Emphasis Type="Italic">SCN4A</Emphasis> mutations in one family suffering from myotonia

Non-dystrophic myotonias are characterized by clinical overlap making it challenging to establish genotype-phenotype correlations. We report clinical and electrophysiological findings in a girl and her father concomitantly harbouring single heterozygous mutations in SCN4A and CLCN1 genes. Functional characterization of N1297S hNav1.4 mutant was performed by patch clamp. The patients displayed a mild phenotype, mostly resembling a sodium channel myotonia. The CLCN1 c.501C>G (p.F167L) mutation has been already described in recessive pedigrees, whereas the SCN4A c.3890A>G (p.N1297S) variation is novel. Patch clamp experiments showed impairment of fast and slow inactivation of the mutated Nav1.4 sodium channel. The present findings suggest that analysis of both SCN4A and CLCN1 genes should be considered in myotonic patients with atypical clinical and neurophysiological features.     

Characterization of complete mitochondrial genomes of <Emphasis Type="Italic">Mastacembelus erythrotaenia</Emphasis> and <Emphasis Type="Italic">Mastacembelus armatus</Emphasis> (Synbranchiformes: Mastacembelidae) and phylogenetic studies of Mastacembelidae

Mastacembelus erythrotaenia and Mastacembelus armatus, are economically and ecologically important freshwater fishes and distribute mainly in tropical and subtropical zone. In this study, the complete mitochondrial genomes of M. erythrotaenia and M. armatus were determined. The circle genomes are 16493 and 16487 bp in length, respectively. They contain 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and one control region. All the protein-coding genes use ATG as start codon except COI uses GTG. Most of them have TAA or TA as the stop codon, while COII, ND3, ND4 and Cyt b use T. Phylogenetic trees involving all the available Mastacembelidae species were also constructed, contributing to phylogenetic studies and conservation of these spiny eels.     

<Emphasis Type="Italic">ABCC8</Emphasis> Single Nucleotide Polymorphisms are Associated with Cerebral Edema in Severe TBI

Objective

Cerebral edema (CE) in traumatic brain injury (TBI) is the consequence of multiple underlying mechanisms and is associated with unfavorable outcomes. Genetic variability in these pathways likely explains some of the clinical heterogeneity observed in edema development. A role for sulfonylurea receptor-1 (Sur1) in CE is supported. However, there are no prior studies examining the effect of genetic variability in the Sur1 gene (ABCC8) on the development of CE. We hypothesize that ABCC8 single nucleotide polymorphisms (SNPs) are predictive of CE.

Methods

DNA was extracted from 385 patients. SNPs in ABCC8 were genotyped using the Human Core Exome v1.2 (Illumina). CE measurements included acute CT edema, mean and peak intracranial pressure (ICP), and need for decompressive craniotomy.

Results

Fourteen SNPs with minor allele frequency >0.2 were identified. Four SNPS rs2283261, rs3819521, rs2283258, and rs1799857 were associated with CE measures. In multiple regression models, homozygote-variant genotypes in rs2283261, rs3819521, and rs2283258 had increased odds of CT edema (OR 2.45, p = 0.007; OR 2.95, p = 0.025; OR 3.00, p = 0.013), had higher mean (β = 3.13, p = 0.000; β = 2.95, p = 0.005; β = 3.20, p = 0.008), and peak ICP (β = 8.00, p = 0.001; β = 7.64, p = 0.007; β = 6.89, p = 0.034). The homozygote wild-type genotype of rs1799857 had decreased odds of decompressive craniotomy (OR 0.47, p = 0.004).

Conclusions

This is the first report assessing the impact of ABCC8 genetic variability on CE development in TBI. Minor allele ABCC8 SNP genotypes had increased risk of CE, while major SNP alleles were protective—potentially suggesting an evolutionary advantage. These findings could guide risk stratification, treatment responders, and the development of novel targeted or gene-based therapies against CE in TBI and other neurological disorders.

     

Expression Analysis of <Emphasis Type="Italic">CYFIP1</Emphasis> and <Emphasis Type="Italic">CAMKK2</Emphasis> Genes in the Blood of Epileptic and Schizophrenic Patients

Schizophrenia and epilepsy are two prevalent neurological disorders with high global burden to the society. Genome-wide studies have identified potential underlying causes for these neurological diseases. In the present case-control study, we have assessed expression of CYFIP1 and CAMKK2 genes in the blood samples of epileptic and schizophrenic patients compared with healthy subjects. A total of 180 subjects including 40 epileptic patients, 50 schizophrenic patients, and 90 healthy individuals participated in the study. Expression of the mentioned genes was measured using TaqMan real-time PCR. The results demonstrated a significant upregulation of CYFIP1 gene expression in epileptic patients (P?=?0.029). CAMKK2 was downregulated in female schizophrenic patients compared with female healthy individuals (P?=?0.048). These results may provide new insight into the pathogenesis of epilepsy and schizophrenia and suggest these genes as potential therapeutic targets for these neurological disorders. Future studies should evaluate these results in larger cohorts of patients.     

The complete mitogenome of <Emphasis Type="Italic">Pelochelys cantorii</Emphasis> (<Emphasis Type="Italic">Guangning</Emphasis>) and the comparative analysis of different habitats

Pelochelys cantorii has become one of the most critically endangered species in the world. The complete mitochondrial DNA (mtDNA) genome of P. cantorii (Guangning) was generated by polymerase chain reaction (PCR) amplification, primer-walking sequencing and fragment cloning. The mitochondrial genome is 17,424 base pairs (bp) and contains 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes and one control region. Comparative analyses of complete mitochondrial genome sequences from different habitats, we found that the P. cantorii (unknown) may be wrong identified. And the phylogenetic position of P. cantorii also support this result, maximum likelihood (ML) and Bayesian (BI) analyses were conducted based on 12 heavy-strand PCGs and 2 rRNAs from 18 taxa. P. cantorii (unknown) is not closely related to other P. cantorii, but formed a clade with Apalone spinifera and Apalone ferox.     

Variations in <Emphasis Type="Italic">Disrupted</Emphasis>-<Emphasis Type="Italic">in</Emphasis>-<Emphasis Type="Italic">Schizophrenia 1</Emphasis> gene modulate long-term longitudinal differences in cortical thickness in patients with a first-episode of psychosis

Schizophrenia patients typically present a widespread bilateral cortical thinning from the early stages of the illness. However, there is controversy whether this reduction in cortical thickness (CT) is static or progressive over the evolution of the disorder. Disrupted-in-Schizophrenia 1 (DISC1) is one of the main candidates genes for schizophrenia, as it has been found associated to the illness, and to several endophenotypes of the disorder including structural brain differences. This gene is known to be involved in neurodevelopment and brain maturation processes. We therefore hypothesized that variations in this gene modulate different progressions of CT in psychosis. Seventy-nine Caucasian drug-naive patients experiencing a first episode of non-affective psychosis were genotyped for rs6675281 (Leu607Phe) and rs821616 (Ser704Cys) SNPs of the DISC1 gene. Brain MRIs were carried out at baseline and 3 years after initiating the treatment. Other clinical and socio-demographic variables were recorded to rule out possible confounding effects. Patients homozygous for the Leu allele of the rs6675281 SNP had a significant (p?<?0.05) descend in CT over the 3-years period, while those carrying the Phe allele presented an increase in CT. When combining the two SNPs we found a synergic effect on CT progression, presenting those patients homozygous for Leu607 +Ser704 a more pronounced cortical thinning. In conclusion, DISC1 gene variations may modulate the longitudinal changes in cortical thickness in patients suffering from a first episode of non-affective psychosis.     

Complete plastid genome of <Emphasis Type="Italic">Larix potaninii</Emphasis> var. <Emphasis Type="Italic">macrocarpa</Emphasis>, an endangered conifer endemic to China

Larix potaninii var. macrocarpa Y. W. Law. belongs to the genus Larix within family Pinaceae, is an endangered conifer species endemic to western China. In this study, the complete plastid genome sequence of L. potaninii var. macrocarpa was characterized using next generation Illumina pair-end sequencing data. The chloroplast DNA is 122,642 bp in length, and contains a pair of 436 bp inverted repeat (IR) region, one large single copy (LSC) region of 65,733 bp, and one small single copy (SSC) region of 56,037 bp. The genome contains 110 genes, including 72 protein-coding genes (72 PCG species), 4 ribosomal RNA genes (4 RNA species) and 34 transfer RNA genes (33 tRNA species). The overall G+C content of the whole genome is 38.8%, and the corresponding values of the LSC, SSC and IR regions are 38.0, 39.7 and 37.4%, respectively. Phylogenetic analysis based on 36 chloroplast genomes indicated that L. potaninii var. macrocarpa is closely related to L. potaninii var. chinensis.     

Repeated Failure in Reward Pursuit Alters Innate <Emphasis Type="Italic">Drosophila</Emphasis> Larval Behaviors

Animals always seek rewards and the related neural basis has been well studied. However, what happens when animals fail to get a reward is largely unknown, although this is commonly seen in behaviors such as predation. Here, we set up a behavioral model of repeated failure in reward pursuit (RFRP) in Drosophila larvae. In this model, the larvae were repeatedly prevented from reaching attractants such as yeast and butyl acetate, before finally abandoning further attempts. After giving up, they usually showed a decreased locomotor speed and impaired performance in light avoidance and sugar preference, which were named as phenotypes of RFRP states. In larvae that had developed RFRP phenotypes, the octopamine concentration was greatly elevated, while tβh mutants devoid of octopamine were less likely to develop RFRP phenotypes, and octopamine feeding efficiently restored such defects. By down-regulating tβh in different groups of neurons and imaging neuronal activity, neurons that regulated the development of RFRP states and the behavioral exhibition of RFRP phenotypes were mapped to a small subgroup of non-glutamatergic and glutamatergic octopaminergic neurons in the central larval brain. Our results establish a model for investigating the effect of depriving an expected reward in Drosophila and provide a simplified framework for the associated neural basis.     

microRNA profiling: increased expression of <Emphasis Type="Italic">miR-147a</Emphasis> and <Emphasis Type="Italic">miR-518e</Emphasis> in progressive supranuclear palsy (PSP)

Progressive supranuclear palsy is a sporadic neurodegenerative disorder. Genetic, environmental, and possibly epigenetic factors contribute to disease. In order to better understand the potential role of epigenetic changes in progressive supranuclear palsy, we investigated whether some microRNAs and their target genes are dysregulated. We analyzed expression of 372 well-characterized microRNAs in forebrains of a total of 40 patients and of 40 controls using TaqMan arrays and SYBR Green quantitative real-time PCR. The exploratory cohort included forebrains from 20 patients and 20 controls provided by the Erasmus Medical Centre in Rotterdam, Netherlands. Confirmatory samples were from Jacksonville, Florida, and from Melbourne, Australia. Both microRNA profiling and SYBR Green quantitative real-time PCR revealed significant upregulation of miR-147 (miR-147a) and miR-518e in the exploratory cohort. Highly increased expression of these two microRNAs was validated in the confirmatory samples. Target genes of miR-147a (NF1, ACLY, ALG12) and of miR-518e (CPEB1, JAZF1, RAP1B) were repressed in patients’ forebrains. The results suggest that dysregulation of specific microRNAs contributes to disease by repressing target genes involved in various cellular functions.