Lipoproteins of Actinomyces viscosus induce inflammatory responses through TLR2 in human gingival epithelial cells and macrophages

Actinomyces viscosus has been suggested to be associated with periodontal disease. However, the pathogenicity of this bacterium is not known. In this study, we examined inflammation-inducing activity by A. viscosus. Whole cells and a lipophilic fraction of A. viscosus ATCC19246 induced production of interleukin-8 and tumor necrosis factor alpha from both human oral epithelial cells and human monocytoid cells. This cytokine production was blocked by lipoprotein lipase treatment of the lipophilic fraction. In addition, anti-Toll-like receptor 2 antibody blocked the cytokine production. These results suggest that lipoprotein of A. viscosus triggers inflammatory responses in periodontitis by activation of Toll-like receptor 2.     

Nation-wide litter fall data from 21 forests of the Monitoring Sites 1000 Project in Japan

This data paper reports litter fall data collected in a network of 21 forest sites in Japan. This is the largest litter fall data set freely available in Japan to date. The network is a part of the Monitoring Sites 1000 Project launched by the Ministry of the Environment, Japan. It covers subarctic to subtropical climate zones and the four major forest types in Japan. Twenty-three permanent plots in which usually 25 litter traps were installed were established in old-growth or secondary natural forests. Litter falls were collected monthly from 2004, and sorted into leaves, branches, reproductive structures and miscellaneous. The data provide seasonal patterns and inter-annual dynamics of litter falls, and their geographical patterns, and offer good opportunities for meta-analyses and comparative studies among forests.     

Identification of human Kir2.2 (KCNJ12) gene encoding functional inward rectifier potassium channel in both mammalian cells and Xenopus oocytes

Arginine residue at position 285 (R285) in the intracellular C-terminal domain of inward rectifier potassium channel Kir2.2 is conserved in many species, but missing in previously reported human Kir2.2 sequences. We here identified the human Kir2.2 gene in normal individuals, which contained R285 in the deduced amino-acid sequence (hKir2.2/R285). All 30 individuals we examined were homozygous for Kir2.2/R285 gene. The hKir2.2/R285 was electrophysiologically functional in both mammalian cells and Xenopus oocytes. However, the hKir2.2 missing R285 was functional only in Xenopus oocytes, but not in mammalian cells. Thus, R285 in Kir2.2 is important for its functional expression in mammalian cells.     

Oocyte formation by mitotically active germ cells purified from ovaries of reproductive-age women

Germline stem cells that produce oocytes in vitro and fertilization-competent eggs in vivo have been identified in and isolated from adult mouse ovaries. Here we describe and validate a fluorescence-activated cell sorting-based protocol that can be used with adult mouse ovaries and human ovarian cortical tissue to purify rare mitotically active cells that have a gene expression profile that is consistent with primitive germ cells. Once established in vitro, these cells can be expanded for months and can spontaneously generate 35- to 50-μm oocytes, as determined by morphology, gene expression and haploid (1n) status. Injection of the human germline cells, engineered to stably express GFP, into human ovarian cortical biopsies leads to formation of follicles containing GFP-positive oocytes 1-2 weeks after xenotransplantation into immunodeficient female mice. Thus, ovaries of reproductive-age women, similar to adult mice, possess rare mitotically active germ cells that can be propagated in vitro as well as generate oocytes in vitro and in vivo.     

Genomic analysis of the rhg1 locus: candidate genes that underlie soybean resistance to the cyst nematode

The rhg1 gene or genes lie at a recessive or co-dominant locus, necessary for resistance to all Hg types of the soybean (Glycine max (L.) Merr.) cyst nematode (Heterodera glycines I.). The aim here was to identify nucleotide changes within a candidate gene found at the rhg1 locus that were capable of altering resistance to Hg types 0 (race 3). A 1.5 ± 0.25 cM region of chromosome 18 (linkage group G) was shown to encompass rhg1 using recombination events from four near isogenic line populations and nine DNA markers. The DNA markers anchored two bacterial artificial chromosome (BAC) clones 21d9 and 73p6. A single receptor like kinase (RLK; leucine rich repeat-transmembrane-protein kinase) candidate resistance gene was amplified from both BACs using redundant primers. The DNA sequence showed nine alleles of the RLK at Rhg1 in the soybean germplasm. Markers designed to detect alleles showed perfect association between allele 1 and resistance to soybean cyst nematode Hg types 0 in three segregating populations, fifteen additional selected recombination events and twenty-two Plant Introductions. A quantitative trait nucleotide in the RLK at rhg1 was inferred that alters A47 to V47 in the context of H297 rather than N297. Contiguous DNA sequence of 315 kbp of chromosome 18 (about 2 cM) contained additional gene candidates that may modulate resistance to other Hg-types including a variant laccase, a hydrogen-sodium ion antiport and two proteins of unknown function. A molecular basis for recessive and co-dominant resistance that involves interactions among paralagous disease-resistance genes was inferred that would improve methods for developing new nematode-resistant soybean cultivars.Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

Competition for Mitogens Regulates Spermatogenic Stem Cell Homeostasis in an Open Niche

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Metabolic changes in Arabidopsis thaliana expressing the feedback-resistant anthranilate synthase alpha subunit gene OASA1D

Anthranilate synthase (AS) is a key enzyme in tryptophan (Trp) biosynthesis. Metabolic changes in transgenic Arabidopsis plants expressing the feedback-resistant anthranilate synthase alpha subunit gene OASA1D were investigated with respect to Trp synthesis and effects on secondary metabolism. The Trp content varied depending on the transgenic line, with some lines showing an approximately 200-fold increase. The levels of AS activity in crude extracts from the transgenic lines were comparable to those in the wild type. On the other hand, the enzyme prepared from the lines accumulating high levels of Trp showed a relaxed feedback sensitivity. The AS activity, determined in the presence of 50 microM L-Trp, correlated well with the amount of free Trp in the transgenic lines, indicating the important role of feedback inhibition in control of Trp pool size. In Arabidopsis, Trp is a precursor of multiple secondary metabolites, including indole glucosinolates and camalexin. The amount of indol-3-ylmethyl glucosinolate (I3 M) in rosette leaves of the high-Trp accumulating lines was 1.5- to 2.1-fold greater than that in wild type. The treatment of the leaves with jasmonic acid resulted in a more pronounced accumulation of I3 M in the high-Trp accumulating lines than in wild type. The induction of camalexin formation after the inoculation of Alternaria brassicicola was not affected by the accumulation of a large amount of Trp. The accumulation of constitutive phenylpropanoids and flavonoids was suppressed in high-Trp accumulating lines, while the amounts of Phe and Tyr increased, thereby indicating an interaction between the Trp branch and the Phe and Tyr branch in the shikimate pathway.     

TGF-beta isoform signaling regulates secondary transition and mesenchymal-induced endocrine development in the embryonic mouse pancreas

Transforming growth factor-beta (TGF-beta) superfamily signaling has been implicated in many developmental processes, including pancreatic development. Previous studies are conflicting with regard to an exact role for TGF-beta signaling in various aspects of pancreatic organogenesis. Here we have investigated the role of TGF-beta isoform signaling in embryonic pancreas differentiation and lineage selection. The TGF-beta isoform receptors (RI, RII and ALK1) were localized mainly to both the pancreatic epithelium and mesenchyme at early stages of development, but then with increasing age localized to the pancreatic islets and ducts. To determine the specific role of TGF-beta isoforms, we functionally inactivated TGF-beta signaling at different points in the signaling cascade. Disruption of TGF-beta signaling at the receptor level using mice overexpressing the dominant-negative TGF-beta type II receptor showed an increase in endocrine precursors and proliferating endocrine cells, with an abnormal accumulation of endocrine cells around the developing ducts of mid-late stage embryonic pancreas. This pattern suggested that TGF-beta isoform signaling may suppress the origination of secondary transition endocrine cells from the ducts. Secondly, TGF-beta isoform ligand inhibition with neutralizing antibody in pancreatic organ culture also led to an increase in the number of endocrine-positive cells. Thirdly, hybrid mix-and-match in vitro recombinations of transgenic pancreatic mesenchyme and wild-type epithelium also led to increased endocrine cell differentiation, but with different patterns depending on the directionality of the epithelial-mesenchymal signaling. Together these results suggest that TGF-beta signaling is important for restraining the growth and differentiation of pancreatic epithelial cells, particularly away from the endocrine lineage. Inhibition of TGF-beta signaling in the embryonic period may thus allow pancreatic epithelial cells to progress towards the endocrine lineage unchecked, particularly as part of the secondary transition of pancreatic endocrine cell development. TGF-beta RII in the ducts and islets may normally serve to downregulate the production of beta cells from embryonic ducts.