Survey of Nonhuman Primates for Antibodies Reactive With Epstein-Barr Virus (EBV) Antigens and Susceptibility of Their Lymphocytes for Immortalization With EBV

The susceptibility to transformation with Epstein-Barr virus (EBV) and the prevalence of antibodies reactive to EBV were examined in 43 primate species. In vitro EBV infection was revealed in lymphocytes from Old World monkeys, including patas monkeys and the colobines, as well as in lymphocytes from the apes. Antibodies reactive to EBV-early antigen/viral capsid antigen (EA/VCA) were detected in all the species of Old World monkeys and apes examined and in two out of seven species of New World monkeys.     

Biotransformation of codeinone to codeine by immobilized cells of papaver somniferum

Papaver somniferum (opium poppy) cells were immobilized in calcium alginate, where they continued to live with their biological activity for 6 months. The immobilized living cells performed the biotransformation of (?)-codeinone to (?)-codeine in both a shake flask and a column bioreactor. The biotransformation ratio in the shake flask (70.4%) was higher than that in the cell suspension (60.8%). Furthermore, 88% of the codeine converted was excreted in the medium. The column bioreactor was functional for 30 days under optimal conditions (20°, 3.75 vvm in aeration), whereas the ratio was 41.9%.     

A tourist element in the 5'-flanking region of the catalase gene CatA reveals evolutionary relationships among Oryza species with various genome types

Tourist-OsaCatA, a transposable element, was found in the 5′-flanking region of the rice gene CatA. The characteristics of this element are similar to those of the other Tourist elements so far found in Oryza sativa. PCR and sequence analyses of 37 accessions of 18 species revealed that all the Oryza species examined, except for one accession, have either a full-length or a partial Tourist element at this locus. Unlike the Tourist elements previously reported, this Tourist element is found in all four Oryza species complexes in the Oryzeae tribe. All AA genome Oryza species, except O. longistaminata, contain the full-length Tourist element. O. longistaminata and the species of the O. officinalis, O. meyeriana and O. ridleyi complexes contain the partial element. A phylogenetic tree of Oryza species based on the nucleotide sequences of these Tourist elements was constructed. The O. longistaminata accessions were placed near the neighboring cluster of the officinalis complex. We propose that the ancestor of O. longistaminata and that of other species with the AA genome diverged, and the ancestor(s) of the O. officinalis, O. ridleyi and O. meyeriana complexes then diverged from the ancestor of O. longistaminata in the course of the evolution of the Oryza species. The Tourist elements associated with CatA and its orthologs thus provide useful tools for examining evolutionary relationships among Oryza species. Received: 12 March 1999 / Accepted: 7 July 1999     

Two populations of Thy1-positive mesenchymal cells regulate in vitro maturation of hepatic progenitor cells

We previously reported that the in vitro maturation of CD49f(+)Thy1(-)CD45(-) (CD49f positive) fetal hepatic progenitor cells (HPCs) is supported by Thy1-positive mesenchymal cells derived from the fetal liver. These mesenchymal cell preparations contain two populations, one of a cuboidal shape and the other spindle shaped in morphology. In this study, we determined that the mucin-type transmembrane glycoprotein gp38 could distinguish cuboidal cells from spindle cells by immunocytochemistry. RT-PCR analysis revealed differences between isolated CD49f(+/-)Thy1(+)gp38(+)CD45(-) (gp38 positive) cells and CD49f(+/-)Thy1(+)gp38(-)CD45(-) (gp38 negative) cells, whereas both cells expressed mesenchymal cell markers. The coculture with gp38-positive cells promoted the maturation of CD49f-positive HPCs, which was estimated by positivity for periodic acid-Schiff (PAS) staining, whereas the coculture with gp38-negative cells maintained CD49f-positive HPCs negative for PAS staining. The expression of mature hepatocyte markers, such as tyrosine aminotransferase, tryptophan-2,3-dioxygenase, and glucose-6-phosphatase, were upregulated on HPCs by coculture with gp38-positive cells. Furthermore, transmission electron microscopy revealed the acquisition of mature hepatocyte features by HPCs cocultured with gp38-positive cells. This effect on maturation of HPCs was inhibited by the addition of conditioned medium derived from gp38-negative cells. By contrast, the upregulation of bromodeoxyuridine incorporation by HPCs demonstrated the proliferative effect of coculture with gp38-negative cells. In conclusion, these results suggest that in vitro maturation of HPCs promoted by gp38-positive cells may be opposed by an inhibitory effect of gp38-negative cells, which likely maintain the immature, proliferative state of HPCs.     

Diploidized eggs reprogram adult somatic cell nuclei to pluripotency in nuclear transfer in medaka fish (Oryzias latipes)

Reprogramming of adult somatic cell nuclei to pluripotency has been unsuccessful in non-mammalian animals, primarily because of chromosomal aberrations in nuclear transplants, which are considered to be caused by asynchrony between the cell cycles of the recipient egg and donor nucleus. In order to normalize the chromosomal status, we used diploidized eggs by retention of second polar body release, instead of enucleated eggs, as recipients in nuclear transfer of primary culture cells from the caudal fin of adult green fluorescent protein gene (GFP) transgenic medaka fish (Oryzias latipes). We found that 2.7% of the reconstructed embryos grew into adults that expressed GFP in various tissues in the same pattern as in the donor fish. Moreover, these fish were diploid, fertile and capable of passing the marker gene to the next generation in Mendelian fashion. We hesitate to call these fish 'clones' because we used non-enucleated eggs as recipients; in effect, they may be chimeras consisting of cells derived from diploid recipient nuclei and donor nuclei. In either case, fish adult somatic cell nuclei were reprogrammed to pluripotency and differentiated into a variety of cell types including germ cells via the use of diploidized recipient eggs.     

Role of Neu4L sialidase and its substrate ganglioside GD3 in neuronal apoptosis induced by catechol metabolites

Mammalian sialidases are key enzymes in the degradation of glycoconjugates. Neu4L sialidase is localized to mitochondria and specifically expressed in brain. To elucidate the pathophysiological roles of Neu4L in the nervous system, we investigated the possible involvement of Neu4L in the apoptotic neurodegeneration under the existence of catechol metabolites generated by tyrosinase. We demonstrated that: (i) the expression level of Neu4L was dramatically decreased prior to apoptosis; (ii) the apoptotic phenotype was characterized by cytochrome c release into cytosol concomitant with the trafficking of ganglioside GD3 to mitochondria; and (iii) the inhibitor of glucosylceramide synthase partially recovered cell viability. Neu4L and its substrate GD3 may act as key molecules in the mitochondrial apoptotic pathway in neuronal cells.     

Less exposure to daily ambient light in winter increases sensitivity of melatonin to light suppression

This study was carried out to examine the seasonal difference in the magnitude of the suppression of melatonin secretion induced by exposure to light in the late evening. The study was carried out in Akita (39 degrees North, 140 degrees East), in the northern part of Japan, where the duration of sunshine in winter is the shortest. Ten healthy male university students (mean age: 21.9+/-1.2 yrs) volunteered to participate twice in the study in winter (from January to February) and summer (from June to July) 2004. According to Japanese meteorological data, the duration of sunshine in Akita in the winter (50.5 h/month) is approximately one-third of that in summer (159.7 h/month). Beginning one week prior to the start of the experiment, the level of daily ambient light to which each subject was exposed was recorded every minute using a small light sensor that was attached to the subject's wrist. In the first experiment, saliva samples were collected every hour over a period of 24 h in a dark experimental room (<15 lux) to determine peak salivary melatonin concentration. The second experiment was conducted after the first experiment to determine the percentage of melatonin suppression induced by exposure to light. The starting time of exposure to light was set 2 h before the time of peak salivary melatonin concentration detected in the first experiment. The subjects were exposed to light (1000 lux) for 2 h using white fluorescent lamps (4200 K). The percentage of suppression of melatonin by light was calculated on the basis of the melatonin concentration determined before the start of exposure to light. The percentage of suppression of melatonin 2 h after the start of exposure to light was significantly greater in winter (66.6+/-18.4%) than summer (37.2+/-33.2%), p<0.01). The integrated level of daily ambient light from rising time to bedtime in summer was approximately twice that in winter. The results suggest that the increase in suppression of melatonin by light in winter is caused by less exposure to daily ambient light.     

Characterization of the rice circadian clock-associated pseudo-response regulators in Arabidopsis thaliana

Members of the small family of Arabidopsis PSEUDO-RESPONSE REGULATORS (PRR1/TOC1, PRR3, PRR5, PRR7, and PRR9) play roles close to the circadian clock in Arabidopsis thaliana. We have reported that the rice (Oryza sativa) genome also encodes a set of PRR counterparts (designated OsPRR1, OsPRR37, OsPRR59, OsPRR73, and OsPRR95 respectively). To gain new insight into the molecular functions of OsPRRs, we carried out genetic complementation analyses by introducing two representative rice genes, OsPRR1 and OsPRR37, into the corresponding Arabidopsis loss-of-function mutants (toc1 and prr7 respectively). The results showed that these OsPRR and AtPRR genes are genetically interchangeable at least in part, suggesting the conserved clock-associated function of these OsPRRs.     

Sequence analysis of full-length cDNA of sex chromosome-linked novel gene 2d-2F9 in Gallus gallus

We obtained two novel W chromosome-linked chick genes by the use of female-male subtraction macroarrays, one of which, 2d-2F9, (recorded as AB188527 in DDBJ) did not have sufficient length (776 bp) to reveal its real form or characteristics. Hence, we obtained full-length Z-linked and W-linked 2d-2F9 genes of 2596 bp and 2589 bp respectively by the oligo-capping and RACE methods.Sequence analysis of these genes not only revealed that there is a counterpart of the W-linked 2d-2F9 gene on the Z chromosome, but also that there is a low homologous area at 5'-UTR between the W- and Z-kinked genes. Using this information, we designed a set of primers to identify sex and to select clones having the Z and W-linked gene (named 2d-2F9-Z and 2d-2F9-W), and also prepared two sets of primers for RT-PCR. These genes were found to be expressed constitutively and ubiquitously from the early embryo to the hatched chick, and they were assigned to the AAA ATP-superfamily.