8 research outputs found
Phosphorothioate antisense oligonucleotides induce the formation of nuclear bodies
Antisense oligonucleotides are powerful tools for the in vivo regulation of gene expression. We have characterized the intracellular distribution of fluorescently tagged phosphorothioate oligodeoxynucleotides (PS-ONs) at high resolution under conditions in which PS-ONs have the potential to display antisense activity. Under these conditions PS-ONs predominantly localized to the cell nucleus where they accumulated in 20-30 bright spherical foci designated phosphorothioate bodies (PS bodies), which were set against a diffuse nucleoplasmic population excluding nucleoli. PS bodies are nuclear structures that formed in cells after PS-ON delivery by transfection agents or microinjection but were observed irrespectively of antisense activity or sequence. Ultrastructurally, PS bodies corresponded to electron-dense structures of 150-300 nm diameter and resembled nuclear bodies that were found with lower frequency in cells lacking PS-ONs. The environment of a living cell was required for the de novo formation of PS bodies, which occurred within minutes after the introduction of PS-ONs. PS bodies were stable entities that underwent noticeable reorganization only during mitosis. Upon exit from mitosis, PS bodies were assembled de novo from diffuse PS-ON pools in the daughter nuclei. In situ fractionation demonstrated an association of PS-ONs with the nuclear matrix. Taken together, our data provide evidence for the formation of a nuclear body in cells after introduction of phosphorothioate oligodeoxynucleotides
Palynology and correlation of the Upper Pennsylvanian Tobra Formation from Zaluch Nala, Salt Range, Pakistan
Samples from the upper 84 m of a 125 m thick section of the Tobra Formation at Zaluch Nala, western Salt Range,
Pakistan yielded palynomorph taxa including the spores Horriditriletes sp. and Microbaculispora tentula, abundant
monosaccate pollen including Barakarites cf. rotatus, Cannanoropollis janakii and Plicatipollenites malabarensis, and
rare taeniate and non-taeniate bisaccate pollen. Converrucosisporites grandegranulatus, Cycadopites cymbatus,
Horriditriletes ramosus, Horriditriletes tereteangulatus and Microbaculispora tentula indicate the South Oman 2165B
Biozone (Late Pennsylvanian), suggesting that the Tobra Formation in Zaluch Nala is equivalent to the middle part
of the Al Khlata Formation of South Oman (Petroleum Development Oman (PDO) Al Khlata production unit AK
P5). Brevitriletes leptoacaina, Brevitriletes parmatus, Horriditriletes ramosus and Microbaculispora tentula indicate
the lower part of the Oman and Saudi Arabia Palynological Zone 2 (OSPZ2). The Tobra Formation assemblages are
also correlated with those from Stage 2 and the eastern Australian Microbaculispora tentula Oppel-zone, based on
the occurrence of Brevitriletes cornutus, Brevitriletes parmatus, Cycadopites cymbatus, Horriditriletes ramosus,
Horriditriletes tereteangulatus and Microbaculispora tentula. The Tobra Formation in Zaluch Nala lacks the
deglaciation sequence that is present in several other palaeogeographically nearby basins such as those of south
Arabia and Western Australia. This is an indication of either non-deposition during the deglaciation period or
erosion associated with the unconformity between the Tobra Formation and the overlying Warchha Formation