2,365 research outputs found
Extensive tRNA gene changes in synthetic Brassica napus
Allopolyploidization, where two species come together to form a new species, plays a major role in speciation and genome evolution. Transfer RNAs (abbreviated tRNA) are typically 73-94 nucleotides in length, and are indispensable in protein synthesis, transferring amino acids to the cell protein synthesis machinery (ribosome). To date, the regularity and function of tRNA gene sequence variation during the process of allopolyploidization have not been well understood. In this study, the inter-tRNA gene corresponding to tRNA amplification polymorphism method was used to detect changes in tRNA gene sequences in the progeny of interspecific hybrids between Brassica rapa and B. oleracea, mimicking the original B. napus (canola) species formation event. Cluster analysis showed that tRNA gene variation during allopolyploidization did not appear to have a genotypic basis. Significant variation occurred in the early generations of synthetic B. napus (F and F generations), but fewer alterations were observed in the later generation (F). The variation-prone tRNA genes tended to be located in AT-rich regions. BlastN analysis of novel tRNA gene variants against a Brassica genome sequence database showed that the variation of these tRNA-gene-associated sequences in allopolyploidization might result in variation of gene structure and function, e.g., metabolic process and transport
Asymptomatic ratio for seasonal H1N1 influenza infection among schoolchildren in Taiwan
Studies indicate that asymptomatic infections do indeed occur frequently for both seasonal and pandemic influenza, accounting for about one-third of influenza infections. Studies carried out during the 2009 pH1N1 pandemic have found significant antibody response against seasonal H1N1 and H3N2 vaccine strains in schoolchildren receiving only pandemic H1N1 monovalent vaccine, yet reported either no symptoms or only mild symptoms
Dynamic expression of cytokine and transcription factor genes during experimental Fasciola gigantica infection in buffaloes
Background
Determining the mechanisms involved in the immune-pathogenesis of the tropical liver fluke, Fasciola gigantica, is crucial to the development of any effective therapeutic intervention. Here, we examined the differential gene expression of cytokines and transcription factors in the liver of F. gigantica-infected buffaloes, over the course of infection.
Methods
Water buffaloes (swamp type) were infected orally with 500 F. gigantica encysted metacercariae. Liver tissue samples were collected 3, 10, 28, 42, 70 and 98 days post-infection (dpi). Levels of gene expression of nine cytokines (IFN-γ, TGF-β, IL-1β, IL-4, IL-6, IL-10, IL-12B, IL-13 and IL-17A) and four transcription factors (T-bet, GATA-3, Foxp3 and ROR-γτ) were determined using quantitative real-time PCR (qRT-PCR). We evaluated any correlation between gene expression of these immune-regulatory factors and the severity of liver pathology.
Results
Histopathological examination revealed that cellular infiltration, hemorrhage and fibrosis without calcification in the liver parenchyma of infected buffaloes, increased over the course of infection. This progressive pathology was attributed to dysregulated and excessive inflammatory responses induced by infection. The early infection phase (3–10 dpi) was marked by a generalized immunosuppression and elevated TGF-β expression in order to facilitate parasite colonization. A mixed Th1/Th2 immune response was dominant from 28 to 70 dpi, to promote parasite survival while minimizing host tissue damage. During late infection (98 dpi), the response was biased towards Th1/Treg in order to inhibit the host’s Th2 protective response and promote chronic infection. Both IL-10 and IL-17A and the Th17/Treg balance, played key roles in mediating the inflammatory and immunoregulatory mechanisms in the liver during chronic fasciolosis.
Conclusions
Our data showed distinct CD4+ T helper (Th) polarization and cytokine dysregulation in response to F. gigantica infection in water buffaloes over the course of infection. Characterizing the temporal expression profiles for host immune genes during infection should provide important information for defining how F. gigantica adapts and survives in the liver of buffaloes and how host immune responses influence F. gigantica pathogenicity
Loop-Mediated Isothermal Amplification Assay Targeting the MOMP Gene for Rapid Detection of Chlamydia psittaci Abortus Strain
For rapid detection of the Chlamydia psittaci abortus strain, a loop-mediated isothermal amplification (LAMP) assay was developed and evaluated in this study. The primers for the LAMP assay were designed on the basis of the main outer membrane protein (MOMP) gene sequence of C. psittaci. Analysis showed that the assay could detect the abortus strain of C. psittaci with adequate specificity. The sensitivity of the test was the same as that of the nested-conventional PCR and higher than that of chick embryo isolation. Testing of 153 samples indicated that the LAMP assay could detect the genome of the C. psittaci abortus strain effectively in clinical samples. This assay is a useful tool for rapid diagnosis of C. psittaci infection in sheep, swine and cattle
Design and Research of Intelligent Remote Control Fan Based on Single Chip Microcomputer and Bluetooth Technology
This paper is designed for intelligent remote control fans. The design of the microcontroller as the core, the sensor, Bluetooth and Andrews system applied to the design of intelligent remote control fan. According to the temperature sensor to achieve the indoor temperature collection, to achieve and set the temperature comparison, thus affecting the fan speed. At the same time, the system according to the infrared sensor components to detect external factors, in order to achieve the running or stopping of the fan, that is, to achieve intelligent control of the fan. In addition, the system achieve the Bluetooth and mobile phone Andrews system of effective combination, and through the software program to complete the fan remote operation and wind speed control
Genomewide association study of leprosy.
BACKGROUND: The narrow host range of Mycobacterium leprae and the fact that it is refractory to growth in culture has limited research on and the biologic understanding of leprosy. Host genetic factors are thought to influence susceptibility to infection as well as disease progression. METHODS: We performed a two-stage genomewide association study by genotyping 706 patients and 1225 controls using the Human610-Quad BeadChip (Illumina). We then tested three independent replication sets for an association between the presence of leprosy and 93 single-nucleotide polymorphisms (SNPs) that were most strongly associated with the disease in the genomewide association study. Together, these replication sets comprised 3254 patients and 5955 controls. We also carried out tests of heterogeneity of the associations (or lack thereof) between these 93 SNPs and disease, stratified according to clinical subtype (multibacillary vs. paucibacillary). RESULTS: We observed a significant association (P<1.00x10(-10)) between SNPs in the genes CCDC122, C13orf31, NOD2, TNFSF15, HLA-DR, and RIPK2 and a trend toward an association (P=5.10x10(-5)) with a SNP in LRRK2. The associations between the SNPs in C13orf31, LRRK2, NOD2, and RIPK2 and multibacillary leprosy were stronger than the associations between these SNPs and paucibacillary leprosy. CONCLUSIONS: Variants of genes in the NOD2-mediated signaling pathway (which regulates the innate immune response) are associated with susceptibility to infection with M. leprae
Foxp2 controls synaptic wiring of corticostriatal circuits and vocal communication by opposing Mef2c
Cortico-basal ganglia circuits are critical for speech and language and are implicated in autism spectrum disorder, in which language function can be severely affected. We demonstrate that in the mouse striatum, the gene Foxp2 negatively interacts with the synapse suppressor gene Mef2c. We present causal evidence that Mef2c inhibition by Foxp2 in neonatal mouse striatum controls synaptogenesis of corticostriatal inputs and vocalization in neonates. Mef2c suppresses corticostriatal synapse formation and striatal spinogenesis, but can itself be repressed by Foxp2 through direct DNA binding. Foxp2 deletion de-represses Mef2c, and both intrastriatal and global decrease of Mef2c rescue vocalization and striatal spinogenesis defects of Foxp2-deletion mutants. These findings suggest that Foxp2-Mef2C signaling is critical to corticostriatal circuit formation. If found in humans, such signaling defects could contribute to a range of neurologic and neuropsychiatric disorders.National Institutes of Health (U.S.) (Grant R37 HD028341)Eunice Kennedy Shriver National Institute of Child Health and Human Development (U.S.) (Award R37 HD028341
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