De novo transcriptome sequencing of drought tolerance-associated genes in little millet (Panicum sumatrense L.)

The genome size of the little millet Panicum sumatrense is unknown, although its genome is fairly diploid (2n = 4x = 36). Despite tremendous nutritional value and adaptability to adverse climatic conditions, P. sumatrense use was limited by their low palatability, coarse grain, and lack of variety of culinary preparations. Hence, understanding how to vary their usage to offer food and nutritional security in the continuously changing modern world, the proposed study was aimed to determine potential genes and metabolites implicated in drought resistance. The drought-resistant genotype of tiny millet OLM-203/Tarini was offered in pots under both relaxed and demanding circumstances. The experimental seedlings were 32 days old and had been under water stress for 23 days. A total of 7606 genes were compared between 23 and 32 days for roots and 7264 total genes were compared between 23 and 32 days for leaves, according to a research on differential expression genes (DEGs). Twenty essential genes for drought tolerance were up-or down-regulated in the control and treated roots of the OLM-203 genotype. For instance, the genes RS193 and XB34 were up-regulated in leaves while, WLIM1 was found to be down-regulated. Gene SKI35 was up-regulated in roots, whereas MPK6 and TCMOp1 were down-regulated in root samples. The roots and leaves of the tiny millet OLM-203 genotype expressed 36 up-regulated and 21 down-regulated serine transcripts, respectively. Gene annotations for leaf samples were classified as having "molecular function" (46%), "cellular component" (19%), and "biological process" (35%), while root sample gene annotations were categorized as having "biological process" (573 contigs), "molecular function" (401 contigs), and "cellular components" (166 contigs). Noteworthy, polyamines play a crucial role in drought stress tolerance in the genotype, and it was found that top ten DEGs encoding for polyamines were common in two tissues (leaf and root). Collectively, transcriptomics profiling (RNA-seq) unveiled transcriptional stability drought stress provide a new insight in underlying modus of operandi in little millet genotype "OLM-203/Tarini" in response to heat stress.

Shifting the limits in wheat research and breeding using a fully annotated reference genome

An annotated reference sequence representing the hexaploid bread wheat genome in 21 pseudomolecules has been analyzed to identify the distribution and genomic context of coding and noncoding elements across the A, B, and D subgenomes. With an estimated coverage of 94% of the genome and containing 107,891 high-confidence gene models, this assembly enabled the discovery of tissue- and developmental stage-related coexpression networks by providing a transcriptome atlas representing major stages of wheat development. Dynamics of complex gene families involved in environmental adaptation and end-use quality were revealed at subgenome resolution and contextualized to known agronomic single-gene or quantitative trait loci. This community resource establishes the foundation for accelerating wheat research and application through improved understanding of wheat biology and genomics-assisted breeding.

Assessment of phytotoxicity of anthracene in soybean (Glycine max) with a quick method of chlorophyll fluorescence

A decrease in photosynthetic efficiency may indicate the toxic effects of environmental pollutants on higher plants. Measurement of chlorophyll (Chl) a fluorescence to assess the performance of photosystem II (PSII) was used as an bioindicator of toxicity of the polycyclic aromatic hydrocarbon (PAH) anthracene (ANT) in soybean plants. The results revealed that ANT treatment caused a reduction in quantum yield of PSII, damage to the oxygen evolving complex, as well as a significant reduction in performance index of PSII. However, change in performance index was more prominent, and it seems that the performance index is a more sensitive parameter to environmental contaminants. Moreover, a change in heterogeneity of PSII was also observed. The number of active reaction centres decreased with increasing concentration of ANT, as secondary plastoquinone reducing centres were converted into non-reducing centres, and PSIIα centres were converted into PSIIβ and PSIIγ centres. The influence of ANT on PSII heterogeneity could be an important reason for reductions in the PSII performance.

Molecular epidemiology of measles in India, 2005-2010

Measles is a childhood disease that causes great morbidity and mortality in India and worldwide. Because measles surveillance in India is in its infancy, there is a paucity of countrywide data on circulating Measles virus genotypes. This study was conducted in 21 of 28 States and 2 of 7 Union Territories of India by MeaslesNetIndia, a national network of 27 centers and sentinel practitioners. MeaslesNetIndia investigated 52 measles outbreaks in geographically representative areas from 2005 through June 2010. All outbreaks were serologically confirmed by detection of antimeasles virus immunoglobulin M (IgM) antibodies in serum or oral fluid samples. Molecular studies, using World Health Organization (WHO)-recommended protocols obtained 203 N-gene, 40 H-gene, and 4 M-gene sequences during this period. Measles genotypes D4, D7, and D8 were found to be circulating in various parts of India during the study period. Further phylogenetic analysis revealed 4 lineages of Indian D8 genotypes: D8a, D8b, D8c, and D8d. This study generated a large, countrywide sequence database that can form the baseline for future molecular studies on measles virus transmission pathways in India. This study has created support and capabilities for countrywide measles molecular surveillance that must be carried forward.

Detection of Mycoplasma species in cell culture by PCR and RFLP based method: effect of BM-cyclin to cure infections

PURPOSE

A two-stage nested polymerase chain reaction (PCR) assay system was described that amplifies the 16S-23S rRNA spacer region sequences of Mycoplasma and Acholeplasma infections in cell cultures and virus stocks.

METHODS

Established cell lines and virus stocks were screened for the presence of Mycoplasma by using nested PCR using two sets of outer and inner primers, amplifies 16S-23S rRNA. PCR and restriction fragment length polymorphism (RFLP) assay was used to detect and identify most of the species-specific Mycoplasmas involved in cell cultures and virus stock contaminants. Infected cultures detected by PCR-RFLP were further treated with BM-cyclin (5 microg/mL) and passaged for three times and tested for Mycoplasma infections by PCR-RFLP.

RESULTS

Mycoplasma pirum and Mycoplasma orale infections were detected by nested PCR. Species specificity was identified by using RFLP of Vsp I, Cla I and Hin dIII restriction enzymes. Mycoplasma infections were cured by treatment with BM-cyclin. This was further confirmed by non-amplification of PCR amplimers in BM-cyclin treated vs. non-treated cultures.

CONCLUSIONS

Regular monitoring of cell cultures for Mycoplasma infections and identification of species-specific Mollicutes will identify the source of contaminations. This approach can be used for quality control of the biological reagents used in cell culture and virology laboratories.

Development of California Public Health Goals (PHGs) for chemicals in drinking water

As part of a program for evaluation of environmental contaminants in drinking water, risk assessments are being conducted to develop Public Health Goals (PHGs) for chemicals in drinking water, based solely on public health considerations. California's Safe Drinking Water Act of 1996 mandated the development of PHGs for over 80 chemicals by 31 December 1999. The law allowed these levels to be set higher or lower than federal maximum contaminant levels (MCLs), including a level of zero if data are insufficient to determine a specific level. The estimated safe levels and toxicological rationale for the first 26 of these chemicals are described here. The chemicals include alachlor, antimony, benzo[a]pyrene, chlordane, copper, cyanide, dalapon, 1,2-dichlorobenzene, 1,4-dichlorobenzene, 2,4-D, diethylhexylphthalate, dinoseb, endothall, ethylbenzene, fluoride, glyphosate, lead, nitrate, nitrite, oxamyl, pentachlorophenol, picloram, trichlorofluoromethane, trichlorotrifluoroethane, uranium and xylene(s). These risk assessments are to be considered by the State of California in revising and developing state MCLs for chemicals in drinking water (which must not exceed federal MCLs). The estimates are also notable for incorporation or consideration of newer guidelines and principles for risk assessment extrapolations.

Reduced T-helper cell function in mice exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

Antibody production to the T-dependent antigen SRBC is highly sensitive to suppression by polychlorinated dibenzo-p-dioxins. The present study provides evidence for a defect in T-helper (TH) cells in TCDD-exposed mice. Because spleen cells from nonimmune TCDD-exposed mice did not show suppressed antibody responses when adoptively transferred to irradiated hosts, we used a hapten-carrier (TNP-SRBC) system with cell separation/reconstitution techniques to determine the effects of TCDD on carrier-specific TH cells. In vitro cultures of spleen cells from SRBC-primed TCDD-treated (5 micrograms/kg) mice produced fewer anti-TNP plaque-forming cells (PFC) when immunized with TNP-SRBC, as compared to cells from primed vehicle-treated controls. A reduced anti-TNP PFC response was also observed in experiments where non-immune B-cells were induced to produce anti-TNP PFC by TH-cells obtained from carrier-primed TCDD-exposed mice, as compared to carrier-primed vehicle-exposed mice. Removal of Lyt-2+ (suppressor) T-cells in these experiments did not alter the anti-TNP PFC response. These results provide direct evidence for reduced activity of TH-cells after exposure to TCDD.

The effects of epoxidized xenobiotics on mitogen responsiveness and antibody-producing ability of murine spleen cells in vitro

The effects of benzo(a)pyrene [B(a)P], B(a)P-4,5- and 7,8-dihydroepoxide, (+)-B(a)P-7,8-diol, (-)-B(a)P-7,8-diol, cholestan-5 alpha,6 alpha-epoxy-3 beta-ol, cholestan-5 beta,6 beta-epoxy-3 beta-ol, cholestantriol and styrene oxide, on the in vitro mitogen responses and antibody-producing ability of mouse spleen cells were evaluated. B(a)P suppressed the plaque-forming cell (PFC) response to T-cell dependent antigen sheep red blood cells (SRBC), but had no effect on the proliferative response to mitogens (phytohemagglutinin, concanavalin A and lipopolysaccharides) except a slight but significant increase to concanavalin A at lower doses. B(a)P-4,5- and 7,8-dihydroepoxides completely inhibited the proliferative response at concentrations exceeding 10(-6) M, but lower concentrations were without any effect. These two epoxides also suppressed the PFC response at concentration greater than or equal to 10(-5) M. This was accompanied by reduced cell viability. (+)-B(a)P-7,8-diol produced a dose-dependent suppression of PFC response to SRBC without altering the cell viability. The proliferative response was inhibited only at concentration greater than or equal to 10(-4) M. In contrast, (-)-B(a)P-7,8-diol has no effect on the PFC response and suppressed the proliferative response only at concentration of greater than or equal to 10(-5) M. Cholestan compounds had no effect on the plaque-forming cell response at concentrations less than or equal to 10(-5) M. The effects on the proliferative response to mitogens were inhibitory and stimulatory depending upon the dose used. Styrene oxide neither inhibited the PFC nor the proliferative responses.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of the Ah locus on the humoral immunotoxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin: evidence for Ah-receptor-dependent and Ah-receptor-independent mechanisms of immunosuppression

There are conflicting reports in the literature regarding the role of the Ah locus in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) immunotoxicity. The present studies have utilized two congenic strains of C57Bl/6 mice that differ only at this locus to assess its influence on TCDD-induced suppression of antibody responses. Mice were given a single oral dose of TCDD 2 days prior to challenge with sheep red blood cells (SRBC) or trinitrophenyl-lipopolysaccharide (TNP-LPS). The subsequent dose-dependent effects of TCDD on the amount of antibody produced by splenic plasma cells were measured using the hemolytic antibody isotope release assay. In addition, the relative importance of the Ah genotype of lymphoid versus nonlymphoid tissue was examined in adoptive transfer experiments. Aryl hydrocarbon hydroxylase (AHH) activity was significantly induced in Ahbb mice by a dose of 0.5 micrograms/kg TCDD and maximally induced by a dose of 2 micrograms/kg. Ahdd mice required 10-fold higher doses of TCDD to induce comparable levels of AHH. The degree of thymic involution and liver hypertrophy induced by TCDD was also influenced by the Ah genotype of the animals. Both Ahbb and Ahdd mice exhibited dose-dependent suppression of the anti-TNP response following TCDD exposure. The ID50 was 7.0 micrograms/kg in Ahbb mice and 30.8 micrograms/kg in Ahdd mice. Suppression of the antibody response to SRBC was also dependent on the Ah locus. The ID50 in Ahbb mice was 0.6 micrograms/kg TCDD. However, an apparent biphasic dose response for suppression of the anti-SRBC response in Ahdd mice suggested the involvement of an Ah-independent component of suppression as well. In adoptive transfer studies, lymphocytes were identified as an Ah-dependent component of the response. The Ah-independent component of the response was not identified, and could be either lymphoid or nonlymphoid in nature. The possibility that T helper cells represent the Ah-independent component is discussed.

In vitro effects of T-2 toxin on the mitogen responsiveness and antibody-producing ability of human lymphocytes

The effects of T-2 toxin on the in vitro mitogen responses and the antibody-producing ability of human peripheral blood lymphocytes were evaluated. T-2 toxin inhibited the mitogen response to concanavalin A (ConA) at a lower concentration (1.6 ng/ml) as compared to phytohemagglutinin (2.4 ng/ml) and pokeweed mitogen (2.4 ng/ml). Maximum inhibition was observed when the toxin was present during the first 8 h; however, the cultures were not refractory to inhibition until 48 h after culture initiation. The antibody-producing ability was inhibited by T-2 toxin concentrations of greater than or equal to 3.2 ng/ml. T-2 toxin did not induce or interfere with the generation of suppressor cells by ConA. The results of this study indicate that various lymphocyte subpopulations have different susceptibilities to T-2 toxin. The activation process associated with lymphocyte proliferation appears to be one of the most sensitive time periods.

Antibody producing ability of mouse spleen cells after subacute dietary exposure to T-2 toxin

The effects of T-2 toxin on the antibody producing ability of CD-1 mice after dietary exposure to 0, 2.5, 5 and 15 ppm of T-2 toxin for 29 days was studied. The antibody response against sheep red blood cells, a T-lymphocyte and macrophage-dependent response was suppressed at 2.5, 5 and 15 ppm of T-2 toxin exposure. In contrast, the antibody responses against dinitrophenyl-aminoethylcarbamylmethyl - Ficoll (DNP - Ficoll), a T-lymphocyte independent macrophage-dependent response, and Escherichia coli 0127 (LPS), a T-lymphocyte and macrophage-independent response, were not affected. These results suggest that the inhibitory effects of T-2 toxin on antibody-producing ability after subacute dietary exposure appear to be a direct affect on T-lymphocyte function, possibly involving the T-helper lymphocytes.

Immunological responsiveness of mouse spleen cells after in vivo or in vitro exposure to 3-acetyldeoxynivalenol

The effects of 3-acetyldeoxynivalenol (3-AcDON) on mitogen-induced lymphocyte proliferation and antibody production were studied in male CD-1 mice exposed to 0, 2.5, 5 or 10 ppm 3-AcDON in the diet for 35 days. Mitogen-induced lymphocyte proliferation and T-cell-independent antibody responses to dinitrophenyl-ficoll or Escherichia coli were not altered by dietary exposure to 3-AcDON. The T-cell-dependent antibody response to sheep red blood cells was increased in the group fed 10 ppm 3-AcDON. In vitro, 3-AcDON inhibited lymphocyte proliferation in a dose-dependent manner. Inhibition was observed when the toxin was present during the first 8 hr in phytohaemagglutinin-stimulated cultures and during the first 24 hr in lipopolysaccharide-stimulated cultures. This suggests that 3-AcDON blocks an early step in lymphocyte activation. This inhibition was not restored by thiol reducing agents (dithiothreitol, L-cysteine or 2-mercaptoethanol). Similarly, the addition of lymphokines, including interleukin-1 or interleukin-2, did not alter the inhibitory effects of 3-AcDON. These results suggest that the in vitro effects of 3-AcDON may not reflect its in vivo immunotoxicity. However, 3-AcDON may serve as a chemical probe for examining the activation process of lymphocyte proliferation.

The effect of cadmium on antibody responses to antigens with different cellular requirements

Six week old BDF1 or CD-1 female mice were exposed to cadmium chloride in the drinking water at concentrations ranging from 0 to 50 ppm cadmium for 3 weeks. The in vivo antibody response against dinitrophenyl-aminoethylcarbamylmethyl-Ficoll (DNP-Ficoll), a T-lymphocyte independent, macrophage dependent response, was enhanced by cadmium. Similarly, the in vivo antibody response against Escherichia coli 0127 (LPS), a T-lymphocyte and macrophage independent response, was also enhanced by cadmium. In contrast, the in vitro antibody response against sheep red blood cells (SRBC), a T-lymphocyte and macrophage dependent response, was suppressed in spleen cell cultures that contained cadmium-exposed non-adherent cells (lymphocytes). Cultures containing cadmium-exposed adherent cells (macrophages) were not suppressed by cadmium. These results suggest that the immunosuppressive effects of cadmium as it relates to humoral immunity involve T-lymphocyte function rather than macrophage or B-lymphocyte activity. The enhanced T-lymphocyte independent antibody responses which accompany suppressed T-lymphocyte-dependent responses following cadmium exposure are an indication of compensatory mechanisms that are associated with the immune system.

In vitro effects of 3-acetyl-deoxynivalenol on the immune response of human peripheral blood lymphocytes

The effects of 3-acetyl-deoxynivalenol (3-AcDON) on the in vitro mitogen responses and the antibody producing ability of human peripheral blood lymphocytes were evaluated. 3-AcDON inhibited the proliferative response to pokeweed mitogen and concanavalin A at a lower concentration (100 ng/ml) as compared to phytohemagglutinin (200 ng/ml). The antibody producing ability was inhibited by 3-AcDON concentrations of greater than or equal to 200 ng/ml. Higher concentrations of 3-AcDON (greater than or equal to 300 ng/ml) produced severe suppression of plaque forming cell response in vitro and reduced the total yield of lymphocytes without altering cell viability. The results of this study indicate that 3-AcDON produces immunosuppressive effects in a dose dependent manner in vitro.

Subacute toxicity of dietary 3-acetyldeoxynivalenol in mice

3-Acetyldeoxynivalenol was incorporated into a semisynthetic diet at levels of 2.5, 5, 10 or 20 ppm and fed to mice for up to 48 days. Body weights and feed consumption were determined, and blood samples for hematological evaluation were taken. Selected tissues were examined microscopically and the humoral immune response was assessed using the Jerne plaque assay. 3-Acetyldeoxynivalenol caused a dose-related depressed feed consumption within the first seven days and reduced body weight until day 14 when fed at levels up to 10 ppm. When fed at a level of 20 ppm, an initial depression in body weight gain and a general malaise were followed by a return to normal. At necropsy, no macroscopic or microscopic lesions could be found. The immune response was not significantly affected after seven or 14 days, but at 21 days, a dose-dependent enhanced response was observed. The findings indicate that, after an initial period of reduced feed intake, animals are apparently able to overcome the toxic effects of 3-acetyldeoxynivalenol.