Morphological differentiation of current-year shoots of deciduous and evergreen lianas in temperate forests in Japan

Morphological variation in current-year shoots within plants was examined in five deciduous and four evergreen liana species from temperate forests in Japan to elucidate the role differentiation in shoots. All lianas had both shoots that twined or developed adventitious roots to gain support on host materials (searcher shoots) and self-supporting shoots with no climbing structures (ordinary shoots). Searcher shoots were 20–295 times longer than ordinary shoots. The allometric relationships between stem length and leaf area differed between searcher and ordinary shoots, and the stem length for a given leaf area was greater in searcher shoots. Leaf area per shoot mass was 1.4–4.3 times higher in ordinary shoots because of the greater allocation to leaf biomass. Searcher shoots comprised only 1–6% of total shoots but 30–85% of total shoot length in deciduous lianas. Ordinary shoots accounted for 70–95% of the total leaf area in these liana species. These results suggest that the exploration of new space was primarily achieved by searcher shoots, whereas a large proportion of current photosynthetic production was achieved by ordinary shoots. The range of stem length and leaf mass ratio of ordinary shoots was similar to that in shoots of tree species. Specialization of shoots in lianas is discussed.     

FTO Gene Polymorphism Is Associated with Type 2 Diabetes through Its Effect on Increasing the Maximum BMI in Japanese Men

AimSeveral studies have demonstrated that polymorphisms within the fat-mass and obesity-associated gene (FTO) are associated with type 2 diabetes (T2D). However, whether the effects of the FTO locus on T2D susceptibility are independent of fat-mass increases remains controversial. To investigate this issue, we examined the association of FTO variants with T2D and various aspects of BMI history during adult life in a Japanese population.MethodsWe genotyped SNPs within FTO (rs1121980 and rs1558902) in 760 Japanese patients with T2D who had reached a lifetime maximum BMI (BMI_max) before or at the time of diagnosis and 693 control individuals with information regarding their BMI_max.ResultsThe BMI_max showed the strongest association with T2D risk among the BMIs evaluated in this study. In the sex-combined analysis, FTO SNPs were not associated with any of the BMI variables or with T2D, but in sex-stratified analyses, both SNPs were significantly associated with the BMI_max and rs1558902 was associated with T2D in men. The association of the SNPs with T2D remained significant after adjustments for the current BMI and age, whereas the T2D association of the SNP was no longer significant after adjustments for BMI_max and age.ConclusionsThese results suggest that the effects of FTO polymorphisms on T2D susceptibility in Japanese men are mediated through their effect on increasing the BMI_max before or at the time of diagnosis.     

Effect of Porphyromonas gingivalis ATCC 33277 Vesicle on Adherence of Streptococcus mutans OMZ 70 to the Experimental Pellicle

The vesicles of Porphyromonas gingivalis ATCC 33277 strongly aggregated Streptococcus cricetus, S. rattus, and S. mutans, but poorly aggregated S. sobrinus. The adherence of S. mutans OMZ 70 to hydroxyapatite (HA) coated with whole saliva was increased in parallel with the quantity of the vesicles. The significant increase of adherence of S. mutans OMZ 70 by the vesicles was also observed on the HA coated with parotid saliva, submandibular saliva, serum, and type I collagen. These findings suggest that the vesicles may act as a bridge between mutans streptococcus and the tooth surface.     

The effects of intramyometrial injection of prostaglandin F2α on severe post-partum hemorrhage

Effectiveness of prostaglandin F₂α (PGF₂α) in controlling post-partum uterine hemorrhage was evaluated with the following results.

1. Systemic administration, whether by continuous i.v. infusion or by gluteal i.m. injection, was not a completely adequate method for hemostasis.

2. Local administration by directly injecting into the uterine musculature, whether transabdominally or transvaginally, resulted in a dramatic reduction of the rate of bleeding.

Routine clinical application of the direct intramyometrial injection of PGF₂α for severe post-partum hemorrhage is recommended in view of its easy performance, excellent hemostatic effect, minimal side effects and good prognosis.     

A Duplicated NUCLEOLIN Gene with Antagonistic Activity Is Required for Chromatin Organization of Silent 45S rDNA in Arabidopsis

In plants as well as in animals, hundreds to thousands of 45S rRNA gene copies localize in Nucleolus Organizer Regions (NORs), and the activation or repression of specific sets of rDNA depends on epigenetic mechanisms. Previously, we reported that the Arabidopsis thaliana nucleolin protein NUC1, an abundant and evolutionarily conserved nucleolar protein in eukaryotic organisms, is required for maintaining DNA methylation levels and for controlling the expression of specific rDNA variants in Arabidopsis. Interestingly, in contrast with animal or yeast cells, plants contain a second nucleolin gene. Here, we report that Arabidopsis NUC1 and NUC2 nucleolin genes are both required for plant growth and survival and that NUC2 disruption represses flowering. However, these genes seem to be functionally antagonistic. In contrast with NUC1, disruption of NUC2 induces CG hypermethylation of rDNA and NOR association with the nucleolus. Moreover, NUC2 loss of function triggers major changes in rDNA spatial organization, expression, and transgenerational stability. Our analyses indicate that silencing of specific rRNA genes is mostly determined by the active or repressed state of the NORs and that nucleolin proteins play a key role in the developmental control of this process.     

Characterization of short-chain dehydrogenase/reductase homologues of Escherichia coli (YdfG) and Saccharomyces cerevisiae (YMR226C)

Short-chain dehydrogenase/reductase homologues from Escherichia coli (YdfG) and Saccharomyces cerevisiae (YMR226C) show high sequence similarity to serine dehydrogenase from Agrobacterium tumefaciens. We cloned each gene encoding YdfG and YMR226C into E. coli JM109 and purified them to homogeneity from the E. coli clones. YdfG and YMR226C consist of four identical subunits with a molecular mass of 27 and 29 kDa, respectively. Both enzymes require NADP⁺ as a coenzyme and use l-serine as a substrate. Both enzymes show maximum activity at about pH 8.5 for the oxidation of l-serine. They also catalyze the oxidation of d-serine, l-allo-threonine, d-threonine, 3-hydroxyisobutyrate, and 3-hydroxybutyrate. The k_cat/K_m values of YdfG for l-serine, d-serine, l-allo-threonine, d-threonine, l-3-hydroxyisobutyrate, and d-3-hydroxyisobutyrate are 105, 29, 199, 109, 67, and 62 M^?1 s^?1, and those of YMR226C are 116, 110, 14600, 7540, 558, and 151 M^?1 s^?1, respectively. Thus, YdfG and YMR226C are NADP⁺-dependent dehydrogenases acting on 3-hydroxy acids with a three- or four-carbon chain, and l-allo-threonine is the best substrate for both enzymes.