Pertussis toxin "Bordetella" is that "B. pertussis" produces PT and the other species do not. "Bordetella parapertussis" shows the most similarity to "B. pertussis" and was therefore used for research determining the role of PT in causing the typical symptoms of whooping cough. Rat studies showed the development of paroxysmal coughing, a characteristic for whooping cough, occurred in rats infected with "B. pertussis". Rats infected with "B. parapertussis" or a PT-deficient mutant of "B. pertussis" did not show this symptom; neither of these two strains produced PT. A large group of bacterial exotoxins are referred to as "A/B toxins", in essence because
Machado–Joseph disease Abandonment" (Berkeley: University of California Press, 2006). Machado–Joseph disease Machado–Joseph disease (MJD), also known as Machado–Joseph Azorean disease, Machado's disease, Joseph's disease or spinocerebellar ataxia type 3 (SCA3), is a rare autosomal dominantly inherited neurodegenerative disease that causes progressive cerebellar ataxia, which results in a lack of muscle control and coordination of the upper and lower extremities. The symptoms are caused by a genetic mutation that results in an expansion of abnormal "CAG" trinucleotide repeats in the ATXN3 gene that results in an abnormal form of the protein ataxin which causes degeneration of cells in the hindbrain. Some symptoms, such