منابع مشابه
Viruses, viroids and vectors
On San Miguel, one of the smallest of the 7 000 islands of the Philippines, a few coconut palms were slowly dying in 1928. Ten years later, 50 000 palms on this island were dead or dying. The disease seemed to be limited to a certain area and affected only coconut palms. No bacteria or fungi were found to be associated with the dying palms. The disease, believed to be caused by a virus, began t...
متن کاملPrions.
The discovery of infectious proteins, denoted prions, was unexpected. After much debate over the chemical basis of heredity, resolution of this issue began with the discovery that DNA, not protein, from pneumococcus was capable of genetically transforming bacteria (Avery et al. 1944). Four decades later, the discovery that a protein could mimic viral and bacterial pathogens with respect to the ...
متن کاملConformaticm of viroids
Viroids are uncoated infectious RNA molecules (MW 107 OOO127 000) known as pathogens of certain higher plants. Thermodynamic and kinetic studies were carried out on highly purified viroid preparations by applying UV-absorption melting analysis and temperature jump methods. The thermal denaturation of viroids is characterized by high thermal stability, high cooperativlty and a high degree of bas...
متن کاملPrions.
Infectious proteins (prions) are usually self-templating filamentous protein polymers (amyloids). Yeast prions are genes composed of protein and, like the multiple alleles of DNA-based genes, can have an array of "variants," each a distinct self-propagating amyloid conformation. Like the lethal mammalian prions and amyloid diseases, yeast prions may be lethal, or only mildly detrimental, and sh...
متن کاملPrions
plants are cloaked in hundreds of tiny projections, known as trichomes. These structures vary in function, shape, size and spacing from species to species, and it’s not known whether similar cellular differentiation programs are responsible for making trichomes in different plants. Trichomes are clearly visible in the scanning electron micrograph of a wild-type Nicotiana tabacum seedling above ...
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ژورنال
عنوان ژورنال: Proceedings of the National Academy of Sciences
سال: 1982
ISSN: 0027-8424,1091-6490
DOI: 10.1073/pnas.79.17.5220