FIG. 7.

Genomic analysis of Hz-1 virus by in situ hybridization with persistently infected TNP3 cells. Genomic signals of Hz-1 virus were detected in interphase (nuclei 1 and 2) and mitotic (nucleus 3) cellular chromosomes. The metaphase spread was counterstained with propidium iodide to outline chromosome morphology (red). The probe derived from the viral genomic DNA was labeled with fluorescein isothiocyanate-conjugated antibody, which resulted in a green color; the overlapping of the viral signal and host chromosome produced a yellow color. (A) Original unprocessed image. (B to E) Series of digitized images of the host chromosomes obtained by optical sectioning (z-axis spacing = 1 μm). Arrows indicate those viral signals which were detectable only in middle sections (C and D) and were thus embedded inside the host chromosomes. (F) In situ hybridization of interphase and mitotic chromosomes of healthy TN368 cells with the same viral probe as negative controls. (G and H) In situ hybridization of dividing TNP3 nuclei, showing equal viral DNA signals associated with the newly divided daughter chromosomes. (G) Viral signals only; (H) dual images of viral signals and propidium iodide-stained nuclei.