Effects of lactoferrin and lactoperoxidase‐containing food on the oral microbiota of older individuals

The oral microbiota influences health and disease states. Some gram‐negative anaerobic bacteria play important roles in tissue destruction associated with periodontal disease. Lactoferrin (LF) and lactoperoxidase (LPO) are antimicrobial proteins found in saliva; however, their influence on the whole oral microbiota currently remains unknown. In this randomized, double‐blinded, placebo‐controlled study, the effects of long‐term ingestion of LF and LPO‐containing tablets on the microbiota of supragingival plaque and tongue coating were assessed. Forty‐six older individuals ingested placebo or test tablets after every meal for 8 weeks. The relative abundance of bacterial species was assessed by 16S rRNA gene high‐throughput sequencing. Most of the bacterial species in supragingival plaque and tongue coating that exhibited significant decreases in the test group were gram‐negative bacteria, including periodontal pathogens. Decreases in the total relative abundance of gram‐negative organisms in supragingival plaque and tongue coating correlated with improvements in assessed variables related to oral health, such as oral malodor and plaque accumulation. Furthermore, there was significantly less microbiota diversity in supragingival plaque at 8 weeks in the test group than in the placebo group and low microbiota diversity correlated with improvements in assessed variables related to oral health. These results suggest that LF and LPO‐containing tablets promote a shift from a highly diverse and gram‐negative‐dominated to a gram‐positive‐dominated community in the microbiota of supragingival plaque and tongue coating. This microbial shift may contribute to improvements in oral health, including oral malodor and state of the gingiva.

     

Isolation and characterization of microsatellite markers for Viola mirabilis (Violaceae) using a next‐generation sequencing platform

We isolated and characterized microsatellite loci in Viola mirabilis (Violaceae), an endangered species from South Korea. Twenty‐three polymorphic microsatellite loci were developed and tested in Korean, Chinese and Japanese populations. The number of alleles per locus varied from two to eight. The observed and expected heterozygosities within the three populations were 0.000–0.625 and 0.469–0.695, respectively. A total of six loci in the Korean population, one locus in the Chinese population and seven loci in the Japanese population deviated from Hardy–Weinberg equilibrium. We expect that these newly developed microsatellite markers will contribute to understanding the phylogeography and population genetics of V. mirabilis, which will aid in developing conservation strategies for this species.     

Genetic Variants in the Bone Morphogenic Protein Gene Family Modify the Association between Residential Exposure to Traffic and Peripheral Arterial Disease

There is a growing literature indicating that genetic variants modify many of the associations between environmental exposures and clinical outcomes, potentially by increasing susceptibility to these exposures. However, genome-scale investigations of these interactions have been rarely performed particularly in the case of air pollution exposures. We performed race-stratified genome-wide gene-environment interaction association studies on European-American (EA, N = 1623) and African-American (AA, N = 554) cohorts to investigate the joint influence of common single nucleotide polymorphisms (SNPs) and residential exposure to traffic (“traffic exposure”)—a recognized vascular disease risk factor—on peripheral arterial disease (PAD). Traffic exposure was estimated via the distance from the primary residence to the nearest major roadway, defined as the nearest limited access highways or major arterial. The rs755249-traffic exposure interaction was associated with PAD at a genome-wide significant level (P = 2.29x10^-8) in European-Americans. Rs755249 is located in the 3’ untranslated region of BMP8A, a member of the bone morphogenic protein (BMP) gene family. Further investigation revealed several variants in BMP genes associated with PAD via an interaction with traffic exposure in both the EA and AA cohorts; this included interactions with non-synonymous variants in BMP2, which is regulated by air pollution exposure. The BMP family of genes is linked to vascular growth and calcification and is a novel gene family for the study of PAD pathophysiology. Further investigation of BMP8A using the Genotype Tissue Expression Database revealed multiple variants with nominally significant (P < 0.05) interaction P-values in our EA cohort were significant BMP8A eQTLs in tissue types highlight relevant for PAD such as rs755249 (tibial nerve, eQTL P = 3.6x10^-6) and rs1180341 (tibial artery, eQTL P = 5.3x10^-6). Together these results reveal a novel gene, and possibly gene family, associated with PAD via an interaction with traffic air pollution exposure. These results also highlight the potential for interactions studies, particularly at the genome scale, to reveal novel biology linking environmental exposures to clinical outcomes.     

The mammals of northern Melanesia: speciation,ecology, and biogeography

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A petal‐specific InMYB1 promoter from Japanese morning glory: a useful tool for molecular breeding of floricultural crops

Production of novel transgenic floricultural crops with altered petal properties requires transgenes that confer a useful trait and petal‐specific promoters. Several promoters have been shown to control transgenes in petals. However, all suffer from inherent drawbacks such as low petal specificity and restricted activity during the flowering stage. In addition, the promoters were not examined for their ability to confer petal‐specific expression in a wide range of plant species. Here, we report the promoter of InMYB1 from Japanese morning glory as a novel petal‐specific promoter for molecular breeding of floricultural crops. First, we produced stable InMYB1_1kb::GUS transgenic Arabidopsis and Eustoma plants and characterized spatial and temporal expression patterns under the control of the InMYB1 promoter by histochemical β‐glucuronidase (GUS) staining. GUS staining patterns were observed only in petals. This result showed that the InMYB1 promoter functions as a petal‐specific promoter. Second, we transiently introduced the InMYB1_1 kb::GUS construct into Eustoma, chrysanthemum, carnation, Japanese gentian, stock, rose, dendrobium and lily petals by particle bombardment. GUS staining spots were observed in Eustoma, chrysanthemum, carnation, Japanese gentian and stock. These results showed that the InMYB1 promoter functions in most dicots. Third, to show the InMYB1 promoter utility in molecular breeding, a MIXTA‐like gene function was suppressed or enhanced under the control of InMYB1 promoter in Arabidopsis. The transgenic plant showed a conspicuous morphological change only in the form of wrinkled petals. Based on these results, the InMYB1 promoter can be used as a petal‐specific promoter in molecular breeding of floricultural crops.     

Leaf vein fraction influences the Péclet effect and 18O enrichment in leaf water

The process of evaporation results in the fractionation of water isotopes such that the lighter ¹⁶O isotope preferentially escapes the gas phase leaving the heavier ¹⁸O isotope to accumulate at the sites of evaporation. This applies to transpiration from a leaf with the degree of fractionation dependent on a number of environmental and physiological factors that are well understood. Nevertheless, the ¹⁸O enrichment of bulk leaf water is often less than that predicted for the sites of evaporation. The advection of less enriched water in the transpiration stream has been suggested to limit the back diffusion of enriched evaporative site water (Péclet effect); however, evidence for this effect has been varied. In sampling across a range of species with different vein densities and saturated water contents, we demonstrate the importance of accounting for the relative ‘pool’ sizes of the vascular and mesophyll water for the interpretation of a Péclet effect. Further, we provide strong evidence for a Péclet signal within the xylem that if unaccounted for can lead to confounding of the estimated enrichment within the mesophyll water. This has important implications for understanding variation in the effective path length of the mesophyll and hence potentially the δ¹⁸O of organic matter.     

The Tau/A152T mutation,a risk factor for frontotemporal‐spectrum disorders,leads to NR2B receptor‐mediated excitotoxicity

We report on a novel transgenic mouse model expressing human full‐length Tau with the Tau mutation A152T (hTau^AT), a risk factor for FTD‐spectrum disorders including PSP and CBD. Brain neurons reveal pathological Tau conformation, hyperphosphorylation, mis‐sorting, aggregation, neuronal degeneration, and progressive loss, most prominently in area CA3 of the hippocampus. The mossy fiber pathway shows enhanced basal synaptic transmission without changes in short‐ or long‐term plasticity. In organotypic hippocampal slices, extracellular glutamate increases early above control levels, followed by a rise in neurotoxicity. These changes are normalized by inhibiting neurotransmitter release or by blocking voltage‐gated sodium channels. CA3 neurons show elevated intracellular calcium during rest and after activity induction which is sensitive to NR2B antagonizing drugs, demonstrating a pivotal role of extrasynaptic NMDA receptors. Slices show pronounced epileptiform activity and axonal sprouting of mossy fibers. Excitotoxic neuronal death is ameliorated by ceftriaxone, which stimulates astrocytic glutamate uptake via the transporter EAAT2/GLT1. In summary, hTau^AT causes excitotoxicity mediated by NR2B‐containing NMDA receptors due to enhanced extracellular glutamate.