Short communication: Localization of Morbillivirus Nucleic Acid in a Pygmy Sperm Whale (Kogia breviceps) by In Situ-Reverse Transcriptase-Polymerase Chain Reaction

Abstract

Combining the sensitivity of PCR and cell-localizing ability of in situ hybridization, the in situ RT-PCR technique was applied to localize cetacean morbillivirus nucleic acid in the lung of a stranded pygmy sperm whale (Kogia breviceps). Primers targeted to phosphoprotein gene of morbillivirus and digoxigenin-11-dUTP was incorporated into the amplicons. Positive signals indicating the presence of morbilliviral specific nucleic acid was clearly found in the type I pneumocyte and mononuclear inflammatory cells in the alveolar septa, space of bronchioli and alveoli. In comparison to previous immunohistochemical findings, in situ RT-PCR provided more direct evidence of causative agents in this case. The result also suggests that in situ RT-PCR with its strength of high sensitivity and natural resistance to sample contamination could be a useful method in the pathogenesis investigation of the morbillivirus infections.