Examination of prezygotic and postzygotic isolating barriers in tropical Ulva (Ulvophyceae, Chlorophyta): evidence for ongoing speciation

Phylogenetic clades based on DNA sequences such as the chloroplast rbcL gene and the nuclear ITS region are frequently used to delimit algal species. However, these molecular markers cannot accurately delimit boundaries among some Ulva species. Although Ulva reticulata and Ulva ohnoi occasionally bloom in tropical to warm-temperate regions and are clearly distinguishable by their reticulate or plain blade morphology, they have few or no sequence divergences in these molecular markers and form a monophyletic clade. In this study, to clarify the speciation and species delimitation in the U. reticulata-ohnoi complex clade, reproductive relationships among several sexual strains from the Philippines and Japan including offspring that originated from the type specimen of U. ohnoi were examined by culturing and hybridization in addition to the ITS-based analysis. As a result, both prezygotic and postzygotic reproductive isolation were revealed to occur between genetically perforated U. reticulata and imperforate U. ohnoi. They were also separated on the basis of sequence analysis of the ITS region. That strongly supports that the two taxa are independent biological species. Although no prezygotic barrier among the Philippine and Japanese strains of U. reticulata was observed, unexpectedly zoospores produced by hybrid sporophytes in some of their combinations mostly failed to develop, indicating partial formation of a postzygotic barrier despite a 0.2% divergence in the ITS sequence. These findings suggest speciation is still ongoing in U. reticulata.

Development of endogenous promoters that drive high-level expression of introduced genes in the model diatom Phaeodactylum tricornutum

The marine diatom Phaeodactylum tricornutum is attractive for basic and applied diatom research. We isolated putative endogenous gene promoters derived from genes that are highly expressed in P. tricornutum: the fucoxanthin chlorophyll a/c-binding protein (FCP) C gene, the vacuolar ATP synthase 16-kDa proteolipid subunit (V-ATPase C) gene, the clumping factor A gene and the solute carrier family 34 member 2 gene. Five putative promoter regions were isolated, linked to an antibiotic resistance gene (Sh ble) and transformed into P. tricornutum. Using quantitative RT-PCR, the promoter activities in the transformants were analyzed and compared to that of the diatom endogenous gene promoter, the FCP A gene promoter which has been used for the transformation of P. tricornutum. Among the five isolated potential promoters, the activity of the V-ATPase C gene promoter was approximately 2.73 times higher than that of the FCP A gene promoter. The V-ATPase C gene promoter drove the expression of Sh ble mRNA transcripts under both light and dark conditions at the stationary phase. These results suggest that the V-ATPase C gene promoter is a novel tool for the genetic engineering of P. tricornutum.

Treatment with Bifemelane for Optic Nerve Damage following High Intraocular Pressure in Rat Eyes

This study found that pretreatment with 4-(o-benzylphenoxy)-N- methylbuty-lamine hydrochloride (bifemelane hydrochloride, Celeport) reduced ischemia-reperfusion injury in rat eyes. Bifemelane (25 mg/kg) was injected intraperitoneally 30 minutes before an ischemic insult, then acute ischemia of the retina and optic disc was induced by increasing intraocular pressure to 110 mmHg for 45 minutes. After one week, the axonal count of the optic nerve was investigated using electron microscopy. The control group consisted of vehicle-treated eyes which received normal saline. The axon count was 93.4 +/- 7.9 for the bifemelane treated group, and 79.2 +/- 6.4 for the controls. The axon count in the treated group was significantly higher. These results suggest that bifemelane, which prevents cerebral nerve cell damage from ischemia, can reduce ischemic retinal nerve cell injury.

An exception among diatoms: unique organization of genes involved in isoprenoid biosynthesis in Rhizosolenia setigera CCMP 1694

The marine diatom Rhizosolenia setigera is unique among this group of microalgae given that it is only one of a handful of diatom species that can produce highly branched isoprenoid (HBI) hydrocarbons. In our efforts to determine distinguishing molecular characteristics in R. setigera CCMP 1694 that could help elucidate the underlying mechanisms for its ability to biosynthesize HBIs, we discovered the occurrence of independent genes encoding for two isopentenyl diphosphate isomerases (RsIDI1 and RsIDI2) and one squalene synthase (RsSQS), enzymes that catalyze non-consecutive steps in isoprenoid biosynthesis. These genes are peculiarly fused in all other genome-sequenced diatoms to date, making their organization in R. setigera CCMP 1694 a clear distinguishing molecular feature. Phylogenetic and sequence analysis of RsIDI1, RsIDI2, and RsSQS revealed that such an arrangement of individually transcribed genes involved in isoprenoid biosynthesis could have arisen through a secondary gene fission event. We further demonstrate that inhibition of squalene synthase (SQS) shifts the flux of exogenous isoprenoid precursors towards HBI biosynthesis suggesting the competition for isoprenoid substrates in the form of farnesyl diphosphate between the sterol and HBI biosynthetic pathways in this diatom.

LSU rDNA based RFLP assays for the routine identification of Gambierdiscus species

The Gambierdiscus genus is a group of benthic dinoflagellates commonly associated with ciguatera fish poisoning (CFP), which is generally found in tropical or sub-tropical regions around the world. Morphologically similar species within the genus can vary in toxicity; however, species identifications are difficult or sometimes impossible using light microscopy. DNA sequencing of ribosomal RNA genes (rDNA) is thus often used to identify and describe Gambierdiscus species and ribotypes, but the expense and time can be prohibitive for routine culture screening and/or large-scale monitoring programs. This study describes a restriction fragment length polymorphism (RFLP) typing method based on analysis of the large subunit rDNA that can successfully identify at least nine of the described Gambierdiscus species and two Fukuyoa species. The software programs DNAMAN 6.0 and Restriction Enzyme Picker were used to identify a set of restriction enzymes (SpeI, HpyCH4IV, and TaqαI) capable of distinguishing most of the known Gambierdiscus species for which DNA sequences were available. This assay was tested using in silico analysis and cultured isolates, and species identifications of isolates assigned by RFLP typing were confirmed by DNA sequencing. To verify the assay and assess intra-specific heterogeneity in RFLP patterns, identifications of 63 Gambierdiscus isolates comprising ten Gambierdiscus species, one ribotype, and two Fukuyoa species were confirmed using RFLP typing, and this method was subsequently employed in the routine identification of isolates collected from the Caribbean Sea. The RFLP assay presented here reduces the time and cost associated with morphological identification via scanning electron microscopy and/or DNA sequencing, and provides a phylogenetically sensitive method for routine Gambierdiscus species assignment.

Toxicity screening of 13 Gambierdiscus strains using neuro-2a and erythrocyte lysis bioassays

Species in the epi-benthic dinoflagellate genus Gambierdiscus produce ciguatoxins (CTXs) and maitotoxins (MTXs), which are among the most potent marine toxins known. Consumption of fish contaminated with sufficient quantities of CTXs causes Ciguatera Fish Poisoning (CFP), the largest cause of non-bacterial food poisoning worldwide. Maitotoxins, which can be found in the digestive system of fish, could also contribute to CFP if such tissues are consumed. Recently, an increasing number of Gambierdiscus species have been identified; yet, little is known about the variation in toxicity among Gambierdiscus strains or species. This study is the first assessment of relative CTX- and MTX-toxicity of Gambierdiscus species from areas as widespread as the North-Eastern Atlantic Ocean, Pacific Ocean and the Mediterranean Sea. A total of 13 strains were screened: (i) seven Pacific strains of G. australes, G. balechii, G. caribaeus, G. carpenteri, G. pacificus, G. scabrosus and one strain of an undetermined species (Gambierdiscus sp. Viet Nam), (ii) five strains from the North-Eastern Atlantic Ocean (two G. australes, a single G. excentricus and two G. silvae strains), and (iii) one G. carolinianus strain from the Mediterranean Sea. Cell pellets of Gambierdiscus were extracted with methanol and the crude extracts partitioned into a CTX-containing dichloromethane fraction and a MTX-containing aqueous methanol fraction. CTX-toxicity was estimated using the neuro-2a cytoxicity assay, and MTX-toxicity via a human erythrocyte lysis assay. Different species were grouped into different ratios of CTX- and MTX-toxicity, however, the ratio was not related to the geographical origin of species (Atlantic, Mediterranean, Pacific). All strains showed MTX-toxicity, ranging from 1.5 to 86pg MTX equivalents (eq) cell^-1. All but one of the strains showed relatively low CTX-toxicity ranging from 0.6 to 50 fg CTX3C eq cell^-1. The exception was the highly toxic G. excentricus strain from the Canary Islands, which produced 1426 fg CTX3C eq cell^-1. As was true for CTX, the highest MTX-toxicity was also found in G. excentricus. Thus, the present study confirmed that at least one species from the Atlantic Ocean demonstrates similar toxicity as the most toxic strains from the Pacific, even if the metabolites in fish have so far been shown to be more toxic in the Pacific Ocean.

[A Pediatric Case of Intractable Cerebrospinal Fluid Leakage after Implantation of an Intrathecal Baclofen Pump]

Intrathecal baclofen(ITB)infusion can offer a useful treatment for severe spasticity;however, numerous complications have been reported. We report a pediatric case in which intractable cerebrospinal fluid(CSF)leakage associated with several inconvenient symptoms arose after implantation of the ITB pump system. A 10-year-old girl with spastic quadriparesis and athetoid cerebral palsy underwent implantation of an ITB delivery system. After discharge, she presented with fluid collection surrounding the pump in the abdomen. The volume of fluid increased and was percutaneously aspirated every other week. However, conservative management failed to relieve fluid collection, which was suspected to be due to CSF leakage. She underwent additional purse-string suture of the point inserted catheter insertion in the back, epidural blood patch, and subfascial implantation of an anchor. However, none of these therapies proved effective. Progressive enlargement of the accumulated fluid was observed. Furthermore, symptoms of ITB withdrawal appeared. Lumbar-peritoneal shunting was performed, and the subcutaneous fluid collection was relieved postoperatively. The course after shunting was uneventful;hence, the dose of baclofen was stabilized. No recurrence of fluid collection was encountered for two years. Intractable CSF leakage was thought to be caused by wasting, occult hydrocephalus, and twisted movements. This case indicates that care is required in the management of CSF leakage after ITB pump implantation.

The effects of light intensity on the growth of Japanese Gambierdiscus spp. (Dinophyceae)

Marine toxic dinoflagellates of the genus Gambierdiscus are the causative agents of ciguatera fish poisoning (CFP), a form of seafood poisoning that is widespread in tropical, subtropical and temperate regions worldwide. The distributions of Gambierdiscus australes, Gambierdiscus scabrosus and two phylotypes of Gambierdiscus spp. type 2 and type 3 have been reported for the waters surrounding the main island of Japan. To explore the bloom dynamics and the vertical distribution of these Japanese species and phylotypes of Gambierdiscus, the effects of light intensity on their growth were tested, using a photoirradiation-culture system. The relationship between the observed growth rates and light intensity conditions for the four species/phylotypes were formulated at R>0.92 (p<0.01) using regression analysis and photosynthesis-light intensity (P-L) model. Based on this equation, the optimum light intensity (L_max) and the semi-optimum light intensity range (L_s-opt) that resulted in the maximum growth rate (μ_max) and ≥80% μ_max values of the four species/phylotypes, respectively, were as follows: (1) the L_max and L_s-opt of G. australes were 208μmol photons m^-2s^-1 and 91-422μmol photons m^-2s^-1, respectively; (2) those of G. scabrosus were 252 and 120-421μmol photons m^-2s^-1, respectively; (3) those of Gambierdiscus sp. type 2 were 192 and 75-430μmol photons m^-2s^-1, respectively; and (4) those of Gambierdiscus sp. type 3 were ≥427 and 73-427μmol photons m^-2s^-1, respectively. All four Gambierdiscus species/phylotypes required approximately 10μmol photons m^-2s^-1 to maintain growth. The light intensities in coastal waters at a site in Tosa Bay were measured vertically at 1m intervals once per season. The relationships between the observed light intensity and depth were formulated using Beer's Law. Based on these equations, the range of the attenuation coefficients at Tosa Bay site was determined to be 0.058-0.119m^-1. The values 1700μmol photons m^-2s^-1, 500μmol photons m^-2s^-1, and 200μmol photons m^-2s^-1 were substituted into the equations to estimate the vertical profiles of light intensity at sunny midday, cloudy midday and rainy midday, respectively. Based on the regression equations coupled with the empirically determined attenuation coefficients for each of the four seasons, the ranges of the projected depths of L_max and L_s-opt for the four Gambierdiscus species/phylotypes under sunny midday conditions, cloudy midday conditions, and rainy midday conditions were 12-38m and 12-54m, 1-16m and 1-33m, and 0m and 0-16m, respectively. These results suggest that light intensity plays an important role in the bloom dynamics and vertical distribution of Gambierdiscus species/phylotypes in Japanese coastal waters.

Spin/orbital and magnetic quantum number selective magnetization measurements for CoFeB/MgO multilayer films

Spin selective magnetic hysteresis (SSMH) curves, orbital selective magnetic hysteresis (OSMH) curves and magnetic quantum number selective SSMH curves are obtained for CoFeB/MgO multilayer films by combining magnetic Compton profile measurements and superconducting quantum interference device (SQUID) magnetometer measurements. Although the SQUID magnetometer measurements do not show perpendicular magnetic anisotropy (PMA) in the CoFeB/MgO multilayer film, PMA behavior is observed in the OSMH and SSMH curves for the |m|  =  2 magnetic quantum number states. These facts indicate that magnetization switching behavior is dominated by the orbital magnetization of the |m|  =  2 magnetic quantum number states.

Scaling up strategies of the chronic respiratory disease programme of the European Innovation Partnership on Active and Healthy Ageing (Action Plan B3: Area 5)

Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) focuses on the integrated care of chronic diseases. Area 5 (Care Pathways) was initiated using chronic respiratory diseases as a model. The chronic respiratory disease action plan includes (1) AIRWAYS integrated care pathways (ICPs), (2) the joint initiative between the Reference site MACVIA-LR (Contre les MAladies Chroniques pour un VIeillissement Actif) and ARIA (Allergic Rhinitis and its Impact on Asthma), (3) Commitments for Action to the European Innovation Partnership on Active and Healthy Ageing and the AIRWAYS ICPs network. It is deployed in collaboration with the World Health Organization Global Alliance against Chronic Respiratory Diseases (GARD). The European Innovation Partnership on Active and Healthy Ageing has proposed a 5-step framework for developing an individual scaling up strategy: (1) what to scale up: (1-a) databases of good practices, (1-b) assessment of viability of the scaling up of good practices, (1-c) classification of good practices for local replication and (2) how to scale up: (2-a) facilitating partnerships for scaling up, (2-b) implementation of key success factors and lessons learnt, including emerging technologies for individualised and predictive medicine. This strategy has already been applied to the chronic respiratory disease action plan of the European Innovation Partnership on Active and Healthy Ageing.

An efficient perovskite solar cell with symmetrical Zn(ii) phthalocyanine infiltrated buffering porous Al2O3 as the hybrid interfacial hole-transporting layer

A new Zn(ii) phthalocyanine (Pc) based low bandgap HTM is introduced for perovskite solar cells. Steady state and time-resolved photoluminescence (PL) measurements indicated an evenly matched hole extraction efficiency between sym-HTPcH and spiro-OMeTAD. On account of the low film quality and resulting high recombination, Zn(ii) Pc normally cannot work as an effective HTM. We adopted insulating Al₂O₃ for the infiltration of sym-HTPcH to form a hybrid interfacial buffer layer, affording perovskite solar cells (PSCs) with an average PCE value of up to 12.3%, which is a significant improvement with respect to the control cell without the meso-Al₂O₃ layer (4.21%) and is the highest value ever reported for Zn(ii) phthalocyanine based devices under AM1.5G standard conditions. A hysteresis test revealed that our device structure with the new HTM exhibited a balanced charge extraction behaviour.

Quantitative PCR assay for detection and enumeration of ciguatera-causing dinoflagellate Gambierdiscus spp. (Gonyaulacales) in coastal areas of Japan

In Japan, ciguatera fish poisoning (CFP) has been increasingly reported not only in subtropical areas but also in temperate areas in recent years, causing a serious threat to human health. Ciguatera fish poisoning is caused by the consumption of fish that have accumulated toxins produced by an epiphytic/benthic dinoflagellate, genus Gambierdiscus. Previous studies revealed the existence of five Gambierdiscus species/phylotypes in Japan: Gambierdiscus australes, Gambierdiscus scabrosus, Gambierdiscus sp. type 2, Gambierdiscus sp. type 3, and Gambierdiscus (Fukuyoa) cf. yasumotoi. Among these, G. australes, G. scabrosus, and Gambierdiscus sp. type 3 strains exhibited toxicities in mice, whereas Gambierdiscus sp. type 2 strains did not show any toxicity. Therefore, it is important to monitor the cell abundance and dynamics of these species/phylotypes to identify and characterize CFP outbreaks in Japan. Because it is difficult to differentiate these species/phylotypes by observation under a light microscope, development of a rapid and reliable detection and enumeration method is needed. In this study, a quantitative PCR assay was developed using a TaqMan probe that targets unique SSU rDNA sequences of four Japanese Gambierdiscus species/phylotypes and incorporates normalization with DNA recovery efficiency. First, we constructed standard curves with high linearity (R²=1.00) and high amplification efficiency (≥1.98) using linearized plasmids that contained SSU rDNA of the target species/phylotypes. The detection limits for all primer and probe sets were approximately 10 gene copies. Further, the mean number of SSU rDNA copies per cell of each species/phylotype was determined from single cells in culture and from those in environmental samples using the qPCR assay. Next, the number of cells of each species/phylotype in the mixed samples, which were spiked with cultured cells of the four species/phylotypes, was calculated by division of the total number of rDNA copies of each species/phylotype in each sample by the number of rDNA copies per cell. The numbers of cells of each species/phylotype quantified by qPCR assay were similar to the number of cells of each species/phylotype that were spiked. Finally, the cell densities of the target species/phylotypes were quantified using the qPCR assay in 30 environmental samples collected from Japanese coastal areas. Total cell densities of the four Gambierdiscus species/phylotypes quantified by qPCR assay were similar to those of Gambierdiscus spp. quantified by direct counting under a light microscope. The qPCR assay developed in this study is expected to be a powerful new tool for determining detailed distribution patterns and for monitoring the cell abundance and dynamics of each Japanese Gambierdiscus species/phylotype in the coastal areas of Japan.

Swallowing Function and Nutritional Status in Japanese Elderly People Receiving Home-care Services: A 1-year Longitudinal Study

OBJECTIVES

Malnutrition is a serious health concern for frail elderly people. Poor oral function leading to insufficient food intake can contribute to the development of malnutrition. In the present study, we explored the longitudinal association of malnutrition with oral function, including oral health status and swallowing function, in elderly people receiving home nursing care.

DESIGN

Prospective observational cohort study with 1-year follow-up.

SETTING

Two mid-sized cities in Fukuoka, Japan from November 2010 to March 2012.

PARTICIPANTS

One hundred and ninety-seven individuals, aged ≥ 60 years, living at home and receiving home-care services because of physical disabilities, without malnutrition.

MEASUREMENTS

Oral health status, swallowing function, taking modified-texture diets such as minced or pureed foods, nutritional status, cognitive function, and activities of daily living were assessed at baseline. The associations between malnutrition at 1-year follow-up and these related factors were analyzed using a logistic regression model.

RESULTS

Swallowing disorders [risk ratio (RR): 5.21, 95% confidence interval (95% CI): 1.65-16.43] were associated with malnutrition. On the other hand, oral health status did not have a direct association with malnutrition.

CONCLUSION

Swallowing disorders may be associated with the incidence of malnutrition in elderly people receiving home-care. The findings indicate that maintaining swallowing function may contribute to the prevention of malnutrition in frail elderly people.

MACVIA-ARIA Sentinel NetworK for allergic rhinitis (MASK-rhinitis): the new generation guideline implementation

Several unmet needs have been identified in allergic rhinitis: identification of the time of onset of the pollen season, optimal control of rhinitis and comorbidities, patient stratification, multidisciplinary team for integrated care pathways, innovation in clinical trials and, above all, patient empowerment. MASK-rhinitis (MACVIA-ARIA Sentinel NetworK for allergic rhinitis) is a simple system centred around the patient which was devised to fill many of these gaps using Information and Communications Technology (ICT) tools and a clinical decision support system (CDSS) based on the most widely used guideline in allergic rhinitis and its asthma comorbidity (ARIA 2015 revision). It is one of the implementation systems of Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA). Three tools are used for the electronic monitoring of allergic diseases: a cell phone-based daily visual analogue scale (VAS) assessment of disease control, CARAT (Control of Allergic Rhinitis and Asthma Test) and e-Allergy screening (premedical system of early diagnosis of allergy and asthma based on online tools). These tools are combined with a clinical decision support system (CDSS) and are available in many languages. An e-CRF and an e-learning tool complete MASK. MASK is flexible and other tools can be added. It appears to be an advanced, global and integrated ICT answer for many unmet needs in allergic diseases which will improve policies and standards.

Effect of an Introduced Phytoene Synthase Gene Expression on Carotenoid Biosynthesis in the Marine Diatom Phaeodactylum tricornutum

Carotenoids exert beneficial effects on human health through their excellent antioxidant activity. To increase carotenoid productivity in the marine Pennales Phaeodactylum tricornutum, we genetically engineered the phytoene synthase gene (psy) to improve expression because RNA-sequencing analysis has suggested that the expression level of psy is lower than other enzyme-encoding genes that are involved in the carotenoid biosynthetic pathway. We isolated psy from P. tricornutum, and this gene was fused with the enhanced green fluorescent protein gene to detect psy expression. After transformation using the microparticle bombardment technique, we obtained several P. tricornutum transformants and confirmed psy expression in their plastids. We investigated the amounts of PSY mRNA and carotenoids, such as fucoxanthin and β-carotene, at different growth phases. The introduction of psy increased the fucoxanthin content of a transformants by approximately 1.45-fold relative to the levels in the wild-type diatom. However, some transformants failed to show a significant increase in the carotenoid content relative to that of the wild-type diatom. We also found that the amount of PSY mRNA at log phase might contribute to the increase in carotenoids in the transformants at stationary phase.

Microarray analysis of 50 patients reveals the critical chromosomal regions responsible for 1p36 deletion syndrome-related complications

OBJECTIVE

Monosomy 1p36 syndrome is the most commonly observed subtelomeric deletion syndrome. Patients with this syndrome typically have common clinical features, such as intellectual disability, epilepsy, and characteristic craniofacial features.

METHOD

In cooperation with academic societies, we analyzed the genomic copy number aberrations using chromosomal microarray testing. Finally, the genotype-phenotype correlation among them was examined.

RESULTS

We obtained clinical information of 86 patients who had been diagnosed with chromosomal deletions in the 1p36 region. Among them, blood samples were obtained from 50 patients (15 males and 35 females). The precise deletion regions were successfully genotyped. There were variable deletion patterns: pure terminal deletions in 38 patients (76%), including three cases of mosaicism; unbalanced translocations in seven (14%); and interstitial deletions in five (10%). Craniofacial/skeletal features, neurodevelopmental impairments, and cardiac anomalies were commonly observed in patients, with correlation to deletion sizes.

CONCLUSION

The genotype-phenotype correlation analysis narrowed the region responsible for distinctive craniofacial features and intellectual disability into 1.8-2.1 and 1.8-2.2 Mb region, respectively. Patients with deletions larger than 6.2 Mb showed no ambulation, indicating that severe neurodevelopmental prognosis may be modified by haploinsufficiencies of KCNAB2 and CHD5, located at 6.2 Mb away from the telomere. Although the genotype-phenotype correlation for the cardiac abnormalities is unclear, PRDM16, PRKCZ, and RERE may be related to this complication. Our study also revealed that female patients who acquired ambulatory ability were likely to be at risk for obesity.