In vitro mutagenesis of Cymbidium La bell “Anna Belle” by γ-rays irradiation and oligochitosan interaction

The optimum media for multiplication of protocorm like bodies (PLBs) and shoot buds of Cymbidium La bell “Anna Belle” were studied in order to prepare the in vitro samples for irradiation. The values of LD50 (lethal dose of 50% samples) of PLBs, shoot buds and plantlets of tested Cymbidium after cultivation of 4 months were also determined about 35.0, 41.0 and 83.1 Gy, respectively. The addition of oligochitosan played as an very important trigger for promotion on the generation of shoot bud from PLBs after irradiation. The in vitro variations have been generated by γ-rays irradiation of PLBs with doses in range of 20 - 50 Gy. The highest mutant frequency (3.83‰) of C. La bell was found by the irradiation of PLB samples at 30 Gy. The different properties of obtained in vitro variations compared to wild types were found to be chlorophyll, short leaves, long leaves, and violet pericardium variations. The genetic relationships among generated variant lines in M1V4 and wild type were analyzed using RAPD techniques

More stories on Th17 cells

For more than two decades, immunologists have been using the so-called Th1/Th2 paradigm to explain most of the phenomena related to adaptive immunity. the Th1/Th2 paradigm implied the existence of two different, mutually regulated, CD4(+) T helper subsets: Th1 cells, driving cell-mediated immune responses involved in tissue damage and fighting infection against intracellular parasites; and Th2 cells that mediate IgE production and are particularly involved in eosinophilic inflammation, allergy and clearance of helminthic infections. A third member of the T helper set, IL-17-producing CD4(+) T cells, now called Th17 cells, was recently described as a distinct lineage that does not share developmental pathways with either Th1 or Th2 cells. the Th17 subset has been linked to autoimmune disorders, being able to produce IL-17, IL-17F and IL-21 among other inflammatory cytokines. Interestingly, it has been reported that there is not only a cross-regulation among Th1, Th2 and Th17 effector cells but there is also a dichotomy in the generation of Th17 and T regulatory cells. Therefore, Treg and Th17 effector cells arise in a mutually exclusive fashion, depending on whether they are activated in the presence of TGF-beta or TGF-beta plus inflammatory cytokines such as IL-6. This review will address the discovery of the Th17 cells, and recent progress on their development and regulation.Crohn's and Colitis Foundation of AmericaNIHLa Jolla Inst Allergy & Immunol, La Jolla, CA 92037 USAUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilNIH: RO1 AI050265-06Web of Scienc