Which tissue is not expected to harbor BSE prions?

Which tissue is not expected to harbor BSE prions?

• A. Muscle
• B. Brain
• C. Distal ileum
• D. Retina

Answer: (A)

Muscle. In BSE, the infectious prion tends to accumulate in the central nervous system and certain peripheral tissues, not in skeletal muscle. Prions are found prominently in the brain and spinal cord, and also in the retina. The distal ileum, which contains gut-associated lymphoid tissue, can harbor prions during early infection, reflecting the oral route of entry and peripheral replication before spread to the CNS. Because skeletal muscle does not typically harbor prions in natural BSE infections, it is not expected to contain infectious prions.

Muscle. In BSE, the infectious prion tends to accumulate in the central nervous system and certain peripheral tissues, not in skeletal muscle. Prions are found prominently in the brain and spinal cord, and also in the retina. The distal ileum, which contains gut-associated lymphoid tissue, can harbor prions during early infection, reflecting the oral route of entry and peripheral replication before spread to the CNS. Because skeletal muscle does not typically harbor prions in natural BSE infections, it is not expected to contain infectious prions.