100 research outputs found
Corticostriatal Projection Neurons – Dichotomous Types and Dichotomous Functions
The mammalian striatum receives its main excitatory input from the two types of cortical pyramidal neurons of layer 5 of the cerebral cortex – those with only intratelencephalic connections (IT-type) and those sending their main axon to the brainstem via the pyramidal tract (PT-type). These two neurons types are present in layer 5 of all cortical regions, and thus they appear to project together to all parts of striatum. These two neuron types, however, differ genetically, morphologically, and functionally, with IT-type neurons conveying sensory and motor planning information to striatum and PT-type neurons conveying an efference copy of motor commands (for motor cortex at least). Anatomical and physiological data for rats, and more recent data for primates, indicate that these two cortical neuron types also differ in their targeting of the two main types of striatal projection neurons, with the IT-type input preferentially innervating direct pathway neurons and the PT-type input preferentially innervating indirect pathway striatal neurons. These findings have implications for understanding how the direct and indirect pathways carry out their respective roles in movement facilitation and movement suppression, and they have implications for understanding the role of corticostriatal synaptic plasticity in adaptive motor control by the basal ganglia
Analysis of Archived Residual Newborn Screening Blood Spots After Whole Genome Amplification
Deidentified newborn screening bloodspot samples (NBS) represent a valuable potential resource for genomic research if impediments to whole exome sequencing of NBS deoxyribonucleic acid (DNA), including the small amount of genomic DNA in NBS material, can be overcome. For instance, genomic analysis of NBS could be used to define allele frequencies of disease-associated variants in local populations, or to conduct prospective or retrospective studies relating genomic variation to disease emergence in pediatric populations over time. In this study, we compared the recovery of variant calls from exome sequences of amplified NBS genomic DNA to variant calls from exome sequencing of non-amplified NBS DNA from the same individuals. Results: Using a standard alignment-based Genome Analysis Toolkit (GATK), we find 62,000-76,000 additional variants in amplified samples. After application of a unique kmer enumeration and variant detection method (RUFUS), only 38,000-47,000 additional variants are observed in amplified gDNA. This result suggests that roughly half of the amplification-introduced variants identified using GATK may be the result of mapping errors and read misalignment. Conclusions: Our results show that it is possible to obtain informative, high-quality data from exome analysis of whole genome amplified NBS with the important caveat that different data generation and analysis methods can affect variant detection accuracy, and the concordance of variant calls in whole-genome amplified and non-amplified exomes.National Institute of Health P01HD067244, NS076465, R01ES021006Nutritional Science
A non-coding insertional mutation of Grhl2 causes gene over-expression and multiple structural anomalies including cleft palate, spina bifida and encephalocele
Orofacial clefts, including cleft lip and palate (CL/P), and neural tube defects (NTDs) are among the most common congenital anomalies but knowledge of the genetic basis of these conditions remains incomplete. The extent to which genetic risk factors are shared between CL/P, NTDs and related anomalies is also unclear. While identification of causative genes has largely focused on coding and loss of function mutations, it is hypothesised that regulatory mutations account for a portion of the unidentified heritability. We found that excess expression of Grainyhead-like 2 (Grhl2) not only causes spinal NTDs in Axial defects (Axd) mice, but also multiple additional defects affecting the cranial region. These include orofacial clefts comprising midline cleft lip and palate, abnormalities of the craniofacial bones and frontal and/or basal encephalocele, in which brain tissue herniates through the cranium or into the nasal cavity. To investigate the causative mutation in the Grhl2Axd strain, whole genome sequencing identified an approximately 4Â kb LTR retrotransposon insertion which disrupts the non-coding regulatory region, lying approximately 300 base pairs upstream of the 5' UTR. This insertion also lies within a predicted long non-coding RNA, oriented on the reverse strand, which like Grhl2 is over-expressed in Axd (Grhl2Axd) homozygous mutant embryos. Initial analysis of the GRHL2 upstream region in individuals with NTDs or cleft palate revealed rare or novel variants in a small number of cases. We hypothesise that mutations affecting the regulation of GRHL2 may contribute to craniofacial anomalies and NTDs in humans
Differential organization of cortical inputs to striatal projection neurons of the matrix compartment in rats
In prior studies, we described the differential organization of corticostriatal and
thalamostriatal inputs to the spines of direct pathway (dSPNs) and indirect
pathway striatal projection neurons (iSPNs) of the matrix compartment. In the
present electron microscopic (EM) analysis, we have refined understanding of
the relative amounts of cortical axospinous vs. axodendritic input to the two
types of SPNs. Of note, we found that individual dSPNs receive about twice as
many axospinous synaptic terminals from IT-type (intratelencephalically projecting)
cortical neurons as they do from PT-type (pyramidal tract projecting) cortical
neurons. We also found that PT-type axospinous synaptic terminals were about 1.5
times as common on individual iSPNs as IT-type axospinous synaptic terminals.
Overall, a higher percentage of IT-type terminals contacted dSPN than iSPN
spines, while a higher percentage of PT-type terminals contacted iSPN than
dSPN spines. Notably, IT-type axospinous synaptic terminals were significantly
larger on iSPN spines than on dSPN spines. By contrast to axospinous
input, the axodendritic PT-type input to dSPNs was more substantial than that
to iSPNs, and the axodendritic IT-type input appeared to be meager and
comparable for both SPN types. The prominent axodendritic PT-type input to
dSPNs may accentuate their PT-type responsiveness, and the large size of
axospinous IT-type terminals on iSPNs may accentuate their IT-type responsiveness.
Using transneuronal labeling with rabies virus to selectively label the cortical
neurons with direct input to the dSPNs projecting to the substantia nigra pars
reticulata, we found that the input predominantly arose from neurons in the upper
layers of motor cortices, in which IT-type perikarya predominate. The differential
cortical input to SPNs is likely to play key roles in motor control and motor
learning
Aberrant epigenetic changes and gene expression in cloned cattle dying around birth
<p>Abstract</p> <p>Background</p> <p>Aberrant reprogramming of donor somatic cell nuclei may result in many severe problems in animal cloning. To assess the extent of abnormal epigenetic modifications and gene expression in clones, we simultaneously examined DNA methylation, histone H4 acetylation and expression of six genes (<it>β-actin</it>, <it>VEGF</it>, <it>oct4</it>, <it>TERT</it>, <it>H19 </it>and <it>Igf2</it>) and a repetitive sequence (<it>art2</it>) in five organs (heart, liver, spleen, lung and kidney) from two cloned cattle groups that had died at different stages. In the ED group (early death, n = 3), the cloned cattle died in the perinatal period. The cattle in the LD group (late death, n = 3) died after the perinatal period. Normally reproduced cattle served as a control group (n = 3).</p> <p>Results</p> <p>Aberrant DNA methylation, histone H4 acetylation and gene expression were observed in both cloned groups. The ED group showed relatively fewer severe DNA methylation abnormalities (p < 0.05) but more abnormal histone H4 acetylations (p < 0.05) and more abnormal expression (p < 0.05) of the selected genes compared to the LD group. However, our data also suggest no widespread gene expression abnormalities in the organs of the dead clones.</p> <p>Conclusion</p> <p>Deaths of clones may be ascribed to abnormal expression of a very limited number of genes.</p
Characterization of Bioactive Recombinant Human Lysozyme Expressed in Milk of Cloned Transgenic Cattle
BACKGROUND: There is great potential for using transgenic technology to improve the quality of cow milk and to produce biopharmaceuticals within the mammary gland. Lysozyme, a bactericidal protein that protects human infants from microbial infections, is highly expressed in human milk but is found in only trace amounts in cow milk. METHODOLOGY/PRINCIPAL FINDINGS: We have produced 17 healthy cloned cattle expressing recombinant human lysozyme using somatic cell nuclear transfer. In this study, we just focus on four transgenic cattle which were natural lactation. The expression level of the recombinant lysozyme was up to 25.96 mg/L, as measured by radioimmunoassay. Purified recombinant human lysozyme showed the same physicochemical properties, such as molecular mass and bacterial lysis, as its natural counterpart. Moreover, both recombinant and natural lysozyme had similar conditions for reactivity as well as for pH and temperature stability during in vitro simulations. The gross composition of transgenic and non-transgenic milk, including levels of lactose, total protein, total fat, and total solids were not found significant differences. CONCLUSIONS/SIGNIFICANCE: Thus, our study not only describes transgenic cattle whose milk offers the similar nutritional benefits as human milk but also reports techniques that could be further refined for production of active human lysozyme on a large scale
Editorial: Health effects and pathophysiological mechanisms of one-carbon metabolism nutrients intake throughout the life cycle
Geometric Accuracy Evaluation Method for Subway Stations Based on 3D Laser Scanning
The rapid development of three-dimensional (3D) laser scanning technology has provided a new technical means for the geometric accuracy evaluation of subway stations. With high precision and high efficiency, laser scanning technology can present the construction site condition in a panoramic way, which is essential for achieving high precision and all-round geometric accuracy evaluation. However, when the survey coordinate system of the design building information modeling (BIM) predefined in the design stage is not applied during the laser scanning data acquisition or the BIM loses the survey coordinate system during the interaction, the objects will have different coordinate positions in the point cloud and BIM, which will limit the accuracy comparison between the two data sources. Meanwhile, the existing methods mainly focus on the above overground buildings, and the accuracy evaluation of underground structures mainly focuses on the overall deformation monitoring. So far, the existing methods do not constitute a hierarchical index system to assess the geometric accuracy of various objects in the subway station. This study proposes a method to evaluate the geometric accuracy of subway stations based on laser scanning technology. A coarse-to-fine coordinate registration from point cloud to the design BIM is used to unify coordinates in different reference systems; and geometric accuracy evaluation of different structures in subway stations is achieved by developing geometric accuracy evaluation indexes and technical systems. The method is applied to the geometric accuracy monitoring of the Hongqi Road subway station, and the experimental results verify the reliability of the method
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Characteristics of airborne bacterial communities and antibiotic resistance genes under different air quality levels
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•The compositions of total bacteria and pathogens varied with air quality.•The deterioration of air quality increased the proportion of pathogens in airborne bacteria.•The bioaerosol concentrations and absolute abundances of ARGs were varying with different particle size.•The effects of ions and metals on pathogenic and non-pathogenic bacteria were different.•The deterioration of air quality was detrimental for the dissemination of ARGs.
Pathogenic bacteria and antibiotic resistance genes (ARGs) in bioaerosols are major threats to human health. In this study, the microbial community structure and ARG distribution characteristics of airborne bacteria in total suspended particulates (TSP) and PM2.5 were investigated under different air quality levels in Xinxiang, Central China. The results revealed that with the deterioration of air quality, the concentrations of airborne bacteria in both TSP and PM2.5 decreased; however, the relative amounts of pathogenic bacteria increased. The predominant genera in pathogenic bacteria of Bacillus, Sphingomonas, Corynebacterium, Rhodococcus, and Staphylococcus were identified in both TSP and PM2.5. Although the airborne bacteria concentrations and absolute abundances of ARGs in TSP were higher than those in PM2.5 under identical air quality conditions, the bacterial community structure and relative amounts of pathogenic bacteria were similar. In addition, the relationship between environmental factors of ions, metal elements, and meteorological parameters and the community structures of airborne bacteria and pathogenic bacteria were also analyzed. The effects of soluble ions and metal elements on several dominant genera of total bacteria and pathogenic bacteria differed, probably due to the strong tolerance of pathogenic bacteria to harsh atmospheric environments Different subtypes of ARGs showed various distribution characteristics with variations in air quality. The deterioration of air quality can inhibit the dissemination of ARGs, as the minimum values of all ARGs and class 1 integrase intI1 were observed under Severely Polluted conditions. This study provides a comprehensive understanding of the effect of air pollution levels on the airborne bacteria community composition and ARG distribution
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