RETRACTED: On the Primary Site of Nuclear RNA Synthesis

Abstract

There is increasing cytological evidence that a substantial portion of cytoplasmic ribonucleic acid (RNA) is synthesized in the nucleus (1-4). In two of these papers (3, 4) as well as in earlier work (see pp. 133-135, reference 5) the evidence suggested that the nucleolus was the site (within the nucleus) where RNA synthesis was almost completely localized.Since there are very few nucleoli per nucleus, in most cell types, the observation that the incorporation of RNA precursors into nucleolar RNA is more rapid and occurs much earlier than in other areas casts some doubt on the hypothesis that RNA is a carrier of information from gene to cytoplasm. That is to say, it is difficult to visualize how information from many chromosomal loci could be imparted to RNA synthesized at only a few loci represented by the nucleoli. The hypothesis might still prove valid, however, if one were to assume that RNA was synthesized at many chromosomal loci and was very rapidly transported to the nucleoli where some other activity took place, at a much slower rate. (This other activity might be the conjugation of RNA with protein). Such a hypothesis has been suggested by Woods and Taylor (3).If the latter assumption is valid, then one might find that following a very brief exposure to a radioactive RNA precursor, only non-nudeolar nuclear (or chromosomal) RNA would be labelled. The experiments herein described were concerned with testing this hypothesis. ExperimentalThe methods and materials employed were essentially identical with those described in a more extensive paper (4). Briefly, the procedure was as follows. Human amnion cells of an established cell line (6) were exposed to a normal growth medium containing 30 #c./ml. of tritiated cytidine, (specific activity 360 mc./mi) for * Supported by funds from the University of California Cancer Research Funds and the Brinton Fund for Cancer Research, administered by Dr. David A. Wood.;~ Address after July 1, 1959: Division of Biology, University of Pennsylvania, Philadelphia. § Received for publication, May 5, 1959. periods of 2, 5, and 10 minutes before fixation. Some cells were treated with ribonuclease (0.4 rag. Worthington crystalline RNase/ml. at pH 6.7, incubated at 37°C. for 21/~ hours) and other cells were left untreated. The cells were then covered with autoradiographlc stripping film in the dark, stored for 30 days, and developed in the usual manner. The specimens were then examined by phase contrast and brightfield microscopy. RESULTSExamination of the specimens revealed very slight labelling of the cells after the 2 minute exposure to tritiated cytidine. The 5 minute sample showed significant nuclear, but no cytoplasmic labelling. Contrary to earlier observations, however, there was no very marked labelling over the nucleoli (Fig. 1). On the other hand, at 10 minutes there was already a marked degree of labelling over the nucleoli (Fig. 2). In order to obtain a quantitative measure of the extent of the activity over the nucleoli as contrasted to the rest of the nucleus...

Kinetics of Rapidly Labelled RNA in Human Leukaemia Cells

“…Studies in the three cases in which nucleolar counts were possible showcd little change in nucleolar grain count betwccn 4 and 6 hours, whercas the nuclear chromatin count had passed its peak and was falling at that time. This would be compatible with a shift of RNA from the nuclear chromatin to the nucleolus and then to the cytoplasm (Goldstein and Micou, 1959;Prescott, 1964). The curves of these uridine chase experiments on leukaemic cells may be coinpared with those earlier derived from studies of PHA-induccd lyniphoblasts .…”

Effect of growth hormone on ribonucleic acid metabolism. 1. Incorporation of radioactive phosphate into ribonucleic acid fractions of rat liver

“…Sirlin (1960) and Fitzgerald & Vinijchaikul (1959) have suggested the nucleolus as the seat of RNA synthesis. Other authors (Woods & Taylor, 1959;Goldstein & Micou, 1959) believe that the initial biosynthesis of RNA takes place around the chromatin material which subsequently passes through the nucleolus. The existence of a dual mechanism, i.e.…”

“…Growth hormone might also modify the transfer rate of nuclear RNA into cytoplasmic compartments. Work of several authors has indicated a rapid transfer of RNA from the nucleus to the cytoplasm (Goldstein & Plaut, 1955;Zalokar, 1960;Amano & Leblond, 1960;Perry, 1960;Goldstein & Micou, 1959;Pelling, 1959). A decrease in the quantity of cytoplasmic fractions.…”

Retractions from altmetric and bibliometric perspectives

“…Perhaps the first English-language retraction in history took place in 1756 (Oransky, 2012). The earliest retraction noted by PubMed (at the time of writing) is for a 1959 paper, and was published in 1966 (Goldstein & Eastwood, 1966). The retraction is thought to be "an emerging institution that renders scientific misconduct visible" (Hesselmann, Graf, Schmidt, & Reinhart, 2017, p. 815) and "a window into the scientific process" (Oransky & Marcus, 2010).…”