Ovine pulmonary adenocarcinoma as an animal model for human lung cancer, because OPA is histologically similar to human adenocarcinoma in situ of the lung. Dolly the sheep, the first mammal successfully cloned from an adult somatic cell, was euthanized after it was confirmed that she had OPA. Ovine pulmonary adenocarcinoma Ovine pulmonary adenocarcinoma (OPA), also known as ovine pulmonary adenomatosis, or jaagsiekte, is a chronic and contagious disease of the lungs of sheep and goats. OPA is caused by a retrovirus called jaagsiekte sheep retrovirus (JSRV). The disease has a long incubation period, and therefore signs usually occur in adult animals (over 2
Talking animal Talking animal A talking animal or speaking animal is any non-human animal that can produce sounds or gestures resembling those of a human language. Several species or groups of animals have developed forms of communication which superficially resemble verbal language, however, these are not defined as language because they lack one or more of the defining characteristics, i.e. grammar, syntax, recursion and displacement. Researchers have been successful in teaching some animals to make gestures similar to sign language. However, these animals fail to reach one or more of the criteria accepted as defining language. The term refers to animals which