In vitro construction of different oligomeric forms of lambdadv DNA and studies of their transforming activities.

Plasmid lambdadv1, which is in a dimeric form, was converted to a linear monomer duplex by the action of EcoRI restriction endonuclease that incises at a unique site in this plasmid genome. The resulting products were then joined by Escherichia coli DNA ligase to produce molecules with various oligomeric forms, and from these monomeric, dimeric, or trimeric circular molecules were purified. By transformation of cells with these DNAs, clones were obtained that carried lambdadv1 in a monomeric or dimeric form. The former type of clones have not been generated in vivo, except for one in a different host strain, and carriers of timeric or tetrameric lambdadv1's have not been obtained so far. It was observed that a considerable fraction of these oligomeric circular DNAs were converted to lower oligomers (e.g., from trimer to dimer) during transformation. The characteristics of the monomeric lambdadv1 carriers obtained were compared with those of dimeric lambdadv1 carriers. The stabilities of the plasmids of the two forms were the same. However, the monomeric plasmid carriers were less tolerant to lambdavir phage infection and perpetuated about 30% less plasmid genomes in monomer units. Furthermore, dimeric plasmid carriers appeared spontaneously and accumulated in cultures of the monomeric lambdadv1 carriers.     

Biochemical recognition in seeds: Germination of Rumex obtusifolius is promoted by leaves of facilitative adult conspecifics

Seeds express various germination behaviors in response to competitor plants. However, germination behaviors in response to facilitator plants are not yet well understood. Rumex obtusifolius seedlings usually appear on the ground near adult conspecific plants, and their survival rate under the canopy of adult conspecifics is higher than that outside the canopy, indicating that adult R. obtusifolius plants facilitate their seedling establishments. We hypothesized that emergence of R. obtusifolius seedlings is promoted by cues from adult conspecifics, but emergence of heterospecific seedlings is not. To test this, we investigated emergence responses of seedlings of R. obtusifolius and three other species that grow with R. obtusifolius in the presence of R. obtusifolius leaf phytochemicals. Emergence of R. obtusifolius seedlings was promoted by the presence of R. obtusifolius leaves. In contrast, emergence of other species seedlings was not promoted by R. obtusifolius leaves. We conclude that germination of R. obtusifolius seeds is facilitated in the presence of conspecifics, via water-soluble chemical exposure, and that recognizing these chemicals has adaptive value.     

Partial silencing of fucosyltransferase 8 gene expression inhibits proliferation of Ishikawa cells,a cell line of endometrial cancer

Endometrial cancer is the most common gynecologic malignancy and is associated with increased morbidity each year, including young people. However, its mechanisms of proliferation and progression are not fully elucidated. It is well known that abnormal glycosylation is involved in oncogenesis, and fucosylation is one of the most important types of glycosylation. In particular, fucosyltransferase 8 (FUT8) is the only FUT responsible for α1, 6-linked fucosylation (core fucosylation), and it is involved in various physiological as well as pathophysiological processes, including cancer biology. Therefore, we aimed to identify the expression of FUT8 in endometrial endometrioid carcinoma and investigate the effect of the partial silencing of the FUT8 gene on the cell proliferation of Ishikawa cells, an epithelial-like endometrial cancer cell line. Quantitative real-time PCR analysis showed that FUT8 gene expression was significantly elevated in the endometrial endometrioid carcinoma, compared to the normal endometrium. The immunostaining of FUT8 and Ulex europaeus Agglutinin 1 (UEA-1), a kind of lectin family specifically binding to fucose, was detected endometrial endometrioid carcinoma. The proliferation assay showed FUT8 partial knockdown by transfection of siRNA significantly suppressed the proliferation of Ishikawa cells, concomitant with the upregulation in the gene expressions associated with the interesting pathways associated with de-ubiquitination, aspirin trigger, mesenchymal-epithelial transition (MET) et al. It was suggested that the core fucosylation brought about by FUT8 might be involved in the proliferation of endometrial endometrioid carcinoma cells.     

Population genetic structure in a threatened tree, Pyrus calleryana var. dimorphophylla revealed by chloroplast DNA and nuclear SSR locus polymorphisms

Pyrus calleryana var. dimorphophylla, a variety of Callery pear (Pyrus calleryana), is endemic to the Tokai district of central Japan, and is currently listed as “Endangered”. The remnant habitats and trees are of limited number, and highly fragmented. As the first step in determining appropriate conservation units, genetic diversity and differentiation in this species were investigated using chloroplast DNA (cpDNA) and nuclear simple sequence repeat (SSR) polymorphisms. All possible remnant trees were genotyped, then six populations were defined based on the results of cpDNA haplotype determination and Bayesian clustering approaches performed using the SSR locus data. Some trees appeared to originate from artificial propagation. Some individuals were difficult to differentiate genetically from the related species, Pyrus × uyematsuana, which is considered to be a hybrid between P. calleryana var. dimorphophylla and a possibly naturalized species, Pyrus pyrifolia, implying that introgression between these species may have occurred. In P. calleryana var. dimorphophylla, anthropogenic factors such as propagation and related species planting are probably major causes of complexity in the genetic structure.     

Effects of light and hydrogen peroxide on gene expression of newly identified antioxidant enzymes in the harmful algal bloom species Chattonella marina

ABSTRACT

Antioxidant enzymes are essential proteins that maintain cell proliferation potential by protecting against oxidative stress. They are present in many organisms including harmful algal bloom (HAB) species. We previously identified the antioxidant enzyme 2-Cys peroxiredoxin (PRX) in the raphidophyte Chattonella marina. This enzyme specifically decomposes a hydrogen peroxide (H₂O₂). PRX is the only antioxidant enzyme so far identified in C. marina. This study used mRNA-seq, using Trinity assemble and blastx for annotation, to identify a further five antioxidant enzymes from C. marina: Cu Zn superoxide dismutase (Cu/Zn-SOD), glutathione peroxidase (GPX), catalase (CAT), ascorbate peroxidase (APX) and thioredoxin (TRX). In the gene expression analysis of six enzymes (Cu/Zn-SOD, GPX, CAT, APX, TRX and PRX) using light-acclimated (100 μmol photons m^?2 s^?1) C. marina cells, only PRX gene expression levels were significantly increased by strong light irradiation (1000 μmol photons m^?2 s^?1). H₂O₂ concentration and scavenging activity were also increased and significantly positively correlated with PRX gene expression levels. In dark-acclimated cells, expression levels of all antioxidant enzymes except APX were significantly increased by light irradiation (100 μmol photons m^?2 s^?1). Expression decreased the following day, with the exception of PRX expression. With the exception of CAT, gene expression of antioxidant enzymes was not significantly induced by artificial H₂O₂ treatment, although average gene expression levels were slightly increased in some enzymes. Thus, we suggest that light is the main trigger of gene expression, but the resultant oxidative stress is also a possible factor affecting the gene expression of antioxidant enzymes in C. marina.     

Quercetin intake during lactation modulates the AMP-activated protein kinase pathway in the livers of adult male rat offspring programmed by maternal protein restriction

Quercetin, a naturally occurring flavonoid, has been reported to possess numerous biological activities including activation of adenosine-5’-monophosphate-activated protein kinase (AMPK). We investigated the effects of quercetin intake during lactation on the AMPK activation in the livers of adult offspring programmed by maternal protein restriction during gestation. Pregnant Wistar rats were fed control and low-protein diets during gestation. Following delivery, each dam received a control or 0.2% quercetin-containing control diet during lactation as follows: control on control (CC), control on restricted (LPC) and 0.2% quercetin-containing control on restricted (LPQ). At weaning (week 3), some of the pups from each dam were killed, and the remaining pups (CC, n= 8; LPC, n= 10; LPQ, n= 13) continued to receive a standard laboratory diet and were killed at week 23. Blood chemistry and phosphorylation levels of AMPKα, acetyl-CoA carboxylase (ACC), endothelial nitric oxide synthase (eNOS) and mammalian target of rapamycin (mTOR) in the livers of male offspring were examined. At week 3, the level of phosphorylated AMPK protein in LPQ increased about 1.5- and 2.1-fold compared with LPC and CC, respectively, and the level in LPQ at week 23 increased about 1.9- and 2.9-fold, respectively. A significant increase in phosphorylated ACC and eNOS levels was found in LPQ. There was no significant difference among the three groups in the level of phosphorylated mTOR protein. In conclusion, quercetin intake during lactation up-regulates AMPK activation in the adult offspring of protein-restricted dams and modulates the AMPK pathway in the liver.