Organization of EBV genomes (A–F) and
relationship between SC35 domains and viral DNA (G–I) or RNA (J–L) in
Namalwa cells. The pattern of viral genomes distribution in the
interphase nuclei of Namalwa cell has been established by DNA FISH of
major internal repeat BamHI W. In 34% of cells, a
single dot is observed (A). In 48% of cells, two dots closely spaced
within the whole range of ∼3 μm in the x–y plane of each other are
observed (B). Seventeen percent of cells have duplicated patterns in
three combinations (C–E). A part of the second cell is seen in the
bottom part of D. Spatial localization of viral genomes in the
interphase nuclei has been performed by means of DNA FISH and DAPI
staining. The majority of the signal spatially separated from the
nuclear periphery; the minority of genomes have a more peripheral
nuclear localization; and some dots are close to nuclear periphery (F,
arrowhead). The spatial relationship (documented here by confocal
sections) between viral DNA sequences and SC35 domains has been
performed by DNA FISH and immunocytochemical mapping by means of the
antibody to SC35 splicing factor. In the majority of cells, DNA
sequences (red) are observed exclusively outside of the SC35 domains
(green; G and I). A smaller fraction of DNA loci, and just one locus in
the case of the doublet, is found associated with the outer edge of the
SC35 domain (I). Spatial relationship (documented here by confocal
sections) between EBV pre-mRNA (red) and SC35 domains (green) has been
established by means of RNA FISH and immunocytochemistry. Basically two
categories of distribution are observed in the Namalwa cell line. The
first category comprises viral RNA spatially separated from SC35
domains (J; the spatial separation is well seen in the inset). The
second category includes RNA tightly associated with SC35 domains. This
is the major fraction of RNAs forming tracks. RNA signal exhibits
various extents of overlap with the SC35 domain (K). The
microcluster(s) of SC35 at the pole of RNA accumulations, opposite the
SC35 domain, have been observed (K, inset, arrowhead). Insets represent
edge-filtered images. K and L are two consecutive confocal sections.
Bars, 4.5 μm.