Analysis and application of the En transposable element and genetic study of resistance to Bipolaris maydis in maize

Since its original isolation and molecular characterization, the En (Enhancer) transposable element has been studied extensively. It also has been used as a tool to tag and isolate genes and to elucidate mechanisms of transposition and gene regulation. The first aspect of this dissertation is on the analysis and application of En. Three En-mutable alleles at the maize A2 locus harboring an autonomous En element, but showing different somatic variegation patterns, were studied by PCR and sequence analysis. It is shown that a fine variegation type (late reversions) is caused by En insertion in the 5[superscript]\u27 region, whereas two coarse variegation types (early reversions) are caused by En insertions in the 3[superscript]\u27 region, in the coding sequence of the intronless A2 gene. In the second project, at least one En-mutable allele has been relocated to each of the 20 maize chromosome arms. Because En has been shown to transpose more frequently to closely linked sites, the relocation of En elements to chromosome arms (chromosome labeling) should facilitate the gene tagging process. Progress in transposon tagging of Rp1, a resistance gene to Puccinia sorghi, is reported in the third project. Instability of Rp1 in different transposable element-laden lines is compared;The second aspect of this dissertation is the genetic study of resistance to Bipolaris maydis. This resistance was determined to be monogenically controlled in the 1970\u27s. However, non-monogenic types of resistance were also reported. Data are reported that support a two-gene model of resistance. Two transposable element lines, one chromosome labeling line, the T line, and a Cy (Cycler) line (both Rhm/Rhm) showed ~10[superscript]-5 mutation rates of Rhm to rhm when tested against the recessive rhm/rhm line. The hybrid of the two lines, however, produced ~5% resistant individuals when tested against the same rhm line. It is hypothesized that these two lines possessed two different dominant genes and recombination between the two genes yielded the ~5% resistant individuals. A genetic test showed results consistent with the two-gene model. The possibility of adjacent-1 segregation with the T line has not been excluded, which might result in viable gametes lacking Rhm and expose the effect of the tester rhm allele which will then produce resistant seedlings. A molecular marker exchange analysis is proposed to exclude this possibility

Surface scattering mechanisms of tantalum nitride thin film resistor

In this letter, we utilize an electrical analysis method to develop a TaN thin film resistor with a stricter spec and near-zero temperature coefficient of resistance (TCR) for car-used electronic applications. Simultaneously, we also propose a physical mechanism mode to explain the origin of near-zero TCR for the TaN thin film resistor (TFR). Through current fitting, the carrier conduction mechanism of the TaN TFR changes from hopping to surface scattering and finally to ohmic conduction for different TaN TFRs with different TaN microstructures. Experimental data of current–voltage measurement under successive increasing temperature confirm the conduction mechanism transition. A model of TaN grain boundary isolation ability is eventually proposed to influence the carrier transport in the TaN thin film resistor, which causes different current conduction mechanisms

Targeted association mapping demonstrating the complex molecular genetics of fatty acid formation in soybean

Palmitic acid bi-alleles of Map-6064 in three subpopulations. (TIFF 1235 kb

Immune reconstitution inflammatory syndrome of Kaposi’s sarcoma in an HIV-infected patient

We present a case of Kaposi’s sarcoma-related immune reconstitution inflammatory syndrome in an HIV-infected patient who developed fever, worsening pulmonary infiltrates with respiratory distress, and progression of skin tumors at the popliteal region and thigh that resulted in limitation on movement of the right knee joint at 3.5 months following a significant increase of CD4 count after combination antiretroviral therapy

Razvoj kvantitativnog PCR testa temeljenog na SYBR Green I za identifikaciju cirkovirusa svinja 1, 2 i 3

Porcine Circovirus (PCV) includes Porcine Circovirus 1(PCV1), Porcine Circovirus 2 (PCV2) and Porcine Circovirus 3 (PCV3). In recent years, co-infection exists between PCV1, PCV2 and PCV3 serotypes. Therefore, it is particularly necessary to establish a fast, specific and sensitive SYBR Green I real-time quantitative PCR detection method for PCV1, PCV2 and PCV3. In this experiment, specific primers were selected and the reaction conditions were optimized. A real-time quantitative PCR identification method was established. The results showed the detection limits of this assay were 40.3 copies/μl for PCV1, 25.2 copies/μl for PCV2 and22.4 copies/ μl for PCV3. There was no cross-reactivity with swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine pseudorabies virus (PRV) and porcine parvovirus (PPV). The intra-assay and inter-assay coefficients of variation were less than 1%. The test results of 100 PCV suspected positive samples revealed that the PCV1, PCV2 and PCV3 singular infection rate was 10% (10/100), 64% (64/100) and 52% (52/100), respectively. The PCV1 and PCV2 co-infection rate was 8% (8/100), the PCV1 and PCV3 co-infection rate was 7% (7/100), the PCV2 and PCV3 co-infection rate was 26% (26/100), and the PCV1, PCV2 and PCV3 co-infection rate was 7% (7/100). This method has good specificity, sensitivity and stability. It provides a promising tool for rapid differential detection of PCV1, PCV2 and PCV3.Među cirkovirusima svinja razlikujemo cirkovirus svinja tipa 1 (PCV1), cirkovirus svinja tipa 2 (PCV2) i cirkovirus svinja tipa 3 (PCV3). Posljednjih se godina pojavljuje koinfekcija ovim trima serotipovima, stoga je potrebno uspostaviti brzu, specifičnu i osjetljivu metodu kako bi se kvantitativnim PCR testom temeljenom na SYBR Green I mogli identificirati PCV1, PCV2 i PCV3. U ovom su istraživanju upotrijebljene specifične početnice te su optimizirani uvjeti rekacije za uspostavljanje kvantitativnog PCR-a u stvarnom vremenu. Rezultati su pokazali da su granice detekcije ovog testa 40,3 kopije/μL za PCV1, 25,2 kopije/μL za PCV2 i 22,4 kopije/μL za PCV3. Nije bilo križne reaktivnosti s virusom svinjske kuge (CSFV), virusom reproduktivnog i respiratornog sindroma svinja (PRRSV), virusom pseudobjesnoće svinja (PRV) i parvovirusom svinja (PPV). Koeficijenti varijacije unutar testa i među testovima bili su manji od 1 %. Rezultati analize 100 uzoraka sa sumnjom na PCV pokazali su da je stopa infekcije serotipom PCV1 bila 10% (10/100), PCV2 64% (64/100), a PCV3 52% (52/100). Stopa koinfekcije serotipovima PCV1 i PCV2 bila je 8% (8/100), PCV1 i PCV3 7% (7/100), a PCV2 i PCV3 26% (26/100). Koinfekcija svim trima serotipovima, PCV1, PCV2 i PCV3, bila je 7% (7/100). Metoda primjenjena u ovom istraživanju ima dobru specifičnost, osjetljivost i postojanost te je obećavajući alat za brzo otkrivanje serotipova PCV1, PCV2 i PCV3

Lentivirus-mediated RNA interference targeting the H19 gene inhibits cell proliferation and apoptosis in human choriocarcinoma cell line JAR

BACKGROUND: H19 is a paternally imprinted gene that has been shown to be highly expressed in the trophoblast tissue. Results from previous studies have initiated a debate as to whether noncoding RNA H19 acts as a tumor suppressor or as a tumor promotor in trophoblast tissue. In the present study, we developed lentiviral vectors expressing H19-specific small interfering RNA (siRNA) to specifically block the expression of H19 in the human choriocarcinoma cell line JAR. Using this approach, we investigated the impact of the H19 gene on the proliferation, invasion and apoptosis of JAR cells. Moreover, we examined the effect of H19 knockdown on the expression of insulin-like growth factor 2 (IGF2), hairy and enhancer of split homologue-1 (HES-1) and dual-specific phosphatase 5 (DUSP5) genes. RESULTS: H19 knockdown inhibited apoptosis and proliferation of JAR cells, but had no significant impact on cell invasion. In addition, H19 knockdown resulted in significant upregulation of HES-1 and DUSP5 expression, but not IGF2 expression in JAR cells. CONCLUSIONS: The finding that H19 downregulation could simultaneously inhibit proliferation and apoptosis of JAR cells highlights a putative dual function for H19 in choriocarcinoma and may explain the debate on whether H19 acts as a tumor suppressor or a tumor promotor in trophoblast tissue. Furthermore, upregulation of HES-1 and DUSP5 may mediate H19 downregulation-induced suppression of proliferation and apoptosis of JAR cells

Cinnamaldehyde up-regulates the mRNA expression level of TRPV1 receptor potential ion channel protein and its function in primary rat DRG neurons in vitro

Cinnamaldehyde (1) is a pharmacologically active ingredient isolated from cassia twig (Ramulus Cinnamomi), which is commonly used in herbal remedies to treat fever-related diseases. Both TRPV1 and TRPM8 ion channel proteins are abundantly expressed in sensory neurons, and are assumed to act as a thermosensor, with the former mediating the feeling of warmth and the latter the feeling of cold in the body. Both of them have recently been reported to be involved in thermoregulation. The purpose of this paper is to further uncover the antipyretic mechanisms of 1 by investigating its effects on the mRNA expression levels and functions of both TRPV1 and TRPM8. The results showed that 1 could up-regulate the mRNA expression levels of TRPV1 at both 37 and 39 degrees C, and its calcium-mediating function was significantly increased at 39 degrees C, all of which could not be blocked by pretreatment of the neuronal cells with ruthenium red, a general transient receptor potential (TRP) blocker, indicating that the action of 1 was achieved through a non-TRPA1 channel pathway. In conclusion, the findings in our in vitro studies might account for part of the peripheral molecular mechanisms for the antipyretic action of 1

Excavatoids O and P, New 12-Hydroxybriaranes from the Octocoral Briareum excavatum

Two new 12-hydroxybriarane diterpenoids, designated as excavatoids O (1) and P (2), were isolated from the octocoral Briareum excavatum. The structures of briaranes 1 and 2 were established on the basis of extensive spectral data analysis. Excavatoid P (2) is the first metabolite which possesses a 6β -chlorine atom in briarane analogues