Could someone tell me what in the hell is going on here? Could this be one of the ways in which these viruses end up being in a complex hybrid state?
This is from 2002:
Abstract.Swine influenza virus (SIV) RNA and antigen were detected in 15 naturally infected pigs by in
situ hybridization using a nonradioactive digoxigenin-labeled cDNA probe and by immunohistochemistry using
an influenza virus H1N1–specific monoclonal antibody. A 582–base pair cDNA probe for viral RNA encoding
the nucleocapsid protein of SIV type A H1N1 strain was generated by the reverse transcription polymerase
chain reaction. In situ hybridization and immunohistochemistry gave similar results for serial sections from
each of 15 lung samples. Positive cells typically exhibited a dark brown (in situ hybridization) or red (immunohistochemistry)
reaction product in the nucleus and cytoplasm without background staining. A strong positive
signal for both in situ hybridization and immunohistochemistry was detected mainly in the bronchial and
bronchiolar epithelial cells. A less intense signal was detected in the interstitial and alveolar macrophages.
Simultaneous detection of hybridization and immunohistochemical signals on serial sections provided evidence
that SIV had replicated in positive cells. The in situ hybridization technique developed in this study was useful
for the detection of SIV RNA in tissues taken from naturally infected pigs and may be a valuable technique
for studying the pathogenesis of SIV infection.
"Hybridization was done overnight at 45 C. The digoxigenin-
labeled probe (0.1 ng/ml) was diluted in 300 ml of the
standard hybridization buffer, heated for 10 minutes at 95 C
on a heating block, and quenched on ice before being applied
to the tissue sections."
ResultsThe SIV H1N1 (A/Seoul/20/91) and human influenza
virus H3N2 (A/Johannesberg/33/95) reacted with
the primers of SIV. The primers did not react with
human influenza B (B/Beijing/184/93), PRRSV,
PRCV, TGEV, PEDV, and PCV types 1 and 2. SIV
was isolated from the lung in five pigs (Nos. 2, 5, 6,
11, 14). All five influenza viruses isolated from pigs
were amplified in MDCK cells, and the resulting virus
RNA was reacted with primers specific for SIV by
PCR (Fig. 1). PCR products from each isolate were
sequenced, and their identity was confirmed as influenza
virus (data not shown).
The results of virus isolation, in situ hybridization,
and immunohistochemistry are summarized in Table
1. The morphology of host cells was preserved despite
the relatively high temperature required in parts of the
incubation procedure. In situ hybridization and immunohistochemistry
gave similar results for serial sections
from each of 15 lung samples (Figs. 2, 3). Positive
cells typically exhibited a dark brown (in situ
hybridization) or red (immunohistochemistry) reaction
http://www.vetpathology.org/cgi/reprint/39/1/10.pdf
