Later Stages Of Maturation Research Articles

Impacts of community market development on the residents’ well-being and satisfaction

Purpose This study aims to investigate the attitude and effects that community residents perceive the development of community market as a tourist attraction. The study examines the moderating role of the stages of the community life cycle, particularly the consolidation and stagnation stages, on the perceived tourism impacts concerning the community well-being. Design/methodology/approach Structural equation modelling using partial least squares analysis has been used in this study. This study has collected the responses from 852 respondents who are the residents of the 10 community markets in Thailand. Findings The key findings reveal that under the context of community markets, the economic factor, cultural factor and attitude of residents towards community market development have strong influences on community well-being, while the environmental factor does not show influence. Moreover, a deeper investigation on the stages of community development reveals various emphases on their impacts on the community well-being. The residents of the markets under the consolidation (early maturity) stage perceive the economic and cultural impacts to have more influence on well-being than the other stages, whereas residents of the markets under the stagnation (late maturity) stage perceive that the environmental factor and the attitude of having the community market have more influence. Although the findings that use the community life cycle as a moderating role do not yield significant results, they provide a preliminary understanding of how tourism stages shape the perception of residents on community well-being. Originality/value The findings provide insights into one type of domestic tourism, the community market, which is a common tourist attraction in Thailand. Community markets have not been particularly investigated in previous literature. This study is also among a handful works which apply the tourism life cycle as a moderating role to investigate the perception of residents towards the economic, cultural and environmental impacts on community well-being.

Transient Improvement in Erythropoiesis Is Achieved Via the Chaperone AHSP With Early Administration of Propranolol in Burn Patients.

Burn patients experience erythropoietin resistant anemia in which early commitment and late maturation of erythroblasts are defective. The authors previously showed that propranolol (Prop) treatment restores erythroid committed progenitors, but terminal maturation remains impaired. Hemoglobinization and maturation occur during terminal erythropoiesis and these processes are aided by an erythroblast intrinsic functional protein called alpha-hemoglobin stabilizing protein (AHSP). The authors evaluated the role of AHSP in PBMC- (peripheral blood mono nuclear cell) derived erythroblasts and the implications of Prop in burn patients. Blood samples were collected at three time points from 17 patients receiving standard burn care (SBC) or Prop. Five healthy volunteers provided control plasma (CP). PBMCs were placed in biphasic cultures with 5% autologous plasma (BP) or CP. Erythroblasts were harvested during mid and late maturation stages; the percentage of AHSP+ erythroblasts, AHSP expression, and relative distribution of reticulocytes and polychromatophilic erythroblasts (PolyE) were determined by cytometry. During the second time point (7-10 days postburn), Prop cohort required 35% less transfusions. At mid maturation, PBMCs from Prop-treated patients cultured in BP had 33% more AHSP+ erythroblasts and 40% more AHSP expression compared with SBC. Furthermore, at late maturation, Prop had 50% more reticulocytes and 30% less PolyEs in CP vs BP compared with SBC (11% and 6%, respectively). AHSP is positively associated with late-stage maturation of PBMC-derived erythroblasts in the presence of CP. Albeit transiently, this is more pronounced in Prop than SBC. Early administration of propranolol in burn patients supports erythropoiesis via the chaperone AHSP.

Validating Structural Styles in the Flysch Basin Northern Rif (Morocco) by Means of Thermal Modeling

Vitrinite reflectance and a micro-Raman spectroscopy parameters data set have been acquired on dispersed organic matter of the Maghrebian flysch basin and the Tangiers unit across a NE-SW section in the north-western Rif belt (North Morocco). Thermal maturity shows increasing values from the hinterland to the external unit (from NE to SW). Paleo-thermal indicators show that the internal flysch basin (i.e., the Mauretanian unit) is less mature than the external one, (i.e., the Massylian unit), with Ro% and Ro eq. Raman values ranging from 0.64% to 1.02% (from early mature to late mature stages of hydrocarbon generation). 1D thermal modeling estimates the overburden now totally eroded ranging from 3.1 km to 6.0 km, and has been used as constraint to reconstruct the complete thrust wedge geometry in Miocene times. The reconstructed geometry accounts for high shortening (about 63%) due to the development of an antiformal stack in the frontal part of the wedge made up by the flysch succession. This stacking is interpreted as a consequence of the western translation of the Alboran Domain in the core of the Betic-Rif orogenic system.

Unconventional role of lysosomes in phagocytosis

Lysosomes are generally thought to be required only for the late stages of phagosome maturation, providing the proton pumps (V-ATPases) and hydrolases needed to acidify and degrade the ingested prey. A recent paper by Davis et al. (EMBO J. [2020], doi:10.15252/embj.2019104058) reports the involvement of lysosomes at a much earlier stage, namely in scission of phagosomes from the plasma membrane. Here we analyze these findings, highlighting a number of unexpected observations and unresolved questions.

Insights of the pore system of lacustrine shales from immature to late mature with the aid of petrology, mineralogy and porosimetry: A case study of the Triassic Yanchang Formation of the Ordos Basin, North China

The study of pore network evolution is an important aspect of tight shale reservoir characterization. Pore spaces in shales consist of three major types: interparticle pores and intraparticle pores associated with mineral matrix and organic-matter pores. In this study, the evolution of pore networks for each pore type in lacustrine shales during thermal maturation was studied based on a suite of 19 Triassic Yanchang Formation shale samples from the Ordos Basin across a maturation gradient from immature to late mature (vitrinite reflectance (Ro) from 0.36 to 1.30%). The results show that different pore types follow systematic evolutions during thermal maturation and that the evolution of pore type and pore size is critically controlled by multiple diagenetic processes such as mechanical compaction, cementation, mineral dissolution, clay mineral transformation, and organic matter thermal maturation. Specifically, at immature and early mature stages (Ro < 0.55%), pores associated with mineral matrix are abundant and have moderate pore sizes. Interparticle pores exhibit preferential orientation along clay platelets. At the mature stage (0.55% < Ro < 1.15%), pores associated with mineral matrix have the smallest size, and interparticle pores become less common and show reduced preferential orientation because of mechanical compaction and cementation. Organic-matter pores start to develop at a maturity level of Ro 0.77% and higher. The total porosity and BET specific surface area show minimum values at Ro 1.12%, mainly because pre-existing matrix-related pores are destroyed by mechanical compaction and filled by migrated bitumen and liquid hydrocarbons, and then they increase when Ro exceeds 1.12%, which likely results from the development of secondary organic-matter nanopores due to the generation and expulsion of gaseous hydrocarbons. An increase in pore size of matrix-related pores at the late mature stage (1.15% < Ro < 1.30%) could be a result of dissolution by organic acid generated during organic matter thermal maturation.

Strategic Addition of Different Additives to Improve Silage Fermentation, Aerobic Stability and In Vitro Digestibility of Napier Grasses at Late Maturity Stage

Napier cultivars are widespread in the tropics. To effectively prepare two Napier grasses at the late maturity stageas silage for ruminant feedstock, the silage fermentation characteristics, aerobic stability, in vitro digestibility, and gas kinetics were studied. Napier Pakchong grass (NP) and sweet grass (SG) were harvested at 120 dof regrowth and untreated (control) or treated with normal or a double dose of cellulase, urea, and formic acid. After 30 d of ensiling, the pH values of silages (ranging from 3.91 to 7.79) were affected (p &lt; 0.05) by additives and lower in control and cellulase-treated silages than in urea- and formic acid-treated silages. Adding cellulase resulted in greater lactic acid concentrations in SG silage. Adding urea boosted acetic acid, propionic acid, butyric acid, and ammonia nitrogen levels of silages. Adding formic acid spoiled silages and shortened the aerobic stability of NP silage. Compared with the control, the addition of cellulase at a double dose enhanced in vitrodry matter digestibility, and the gas production kinetics parameters of silages. Taking silage fermentation quality and in vitro dry matter digestibility into consideration, adding cellulase (0.2 g/kg fresh matter) to Napier grasses at the late maturity stage could be a better option compared with the other additives.

Morphometric Analysis and Prioritization of Sub-watersheds for Management of Natural Resources using GIS: a case study of Rajasthan, India

Natural resources management is crucial in water scarce semi-arid regions because of scanty rainfall and over exploitation of ground water resources. The watershed choosen in this study is drained by Bandi River having area of 2162.7 km 2 and located in Pali district of Rajasthan, India. Incessant rainfall, continuous exploitation of ground water results in the reduction of ground water level and recurrent drought conditions in this area. Hence, the watershed had been further divided into 5 sub-watersheds represented as SWS-1 to SWS-5 with geographical area ranging from 98 km 2 to 265 km 2 and perimeter ranging from 47 km to 79 km. These sub watersheds were then prioritized based on morphometric analysis considering the linear, areal and relief aspects of the drainage system in GIS environment using ArcGIS 10.5.5. The analysis showed that the drainage density of sub-watersheds varies between 1.351 km/km 2 to 2.513 km/km 2 and the lowest drainage density was found in SWS-4 that indicated the presence of impermeable sub-soil system with dense vegetation cover and low relief in the sub-watershed. The sub-watershed, SWS-2 has high circularity ratio of 0.6 that indicated the topography at the late maturity stage. Similarly, the Elongation Ratio varied from 0.4007 to 0.9340 in the sub-watersheds indicated comparatively steep ground slope and high relief. After the computation of all morphometric parameters of the sub watersheds, the compound parameter values were calculated and the sub-watershed having the lowest compound parameter value was given the highest priority for conservation measures. In this study, the sub-watershed SWS-1 was found to have the lowest compound value of 1.875 and hence considered for immediate soil conservation and water management measures. https://doi.org/10.23953/cloud.ijarsg.471

MYB5-like and bHLH influence flavonoid composition in pomegranate

The fruit of the pomegranate (Punica granatum L.) is an important nutraceutical food rich in polyphenolic compounds, including hydrolysable tannins, anthocyanins and flavonols. Their composition varies according to cultivar, tissue and fruit development stage and is probably regulated by a combination of MYB and bHLH type transcription factors (TFs). In this study, metabolomics analysis during fruit developmental stages in the main pomegranate cultivars, Wonderful and Valenciana with contrasting colour of their ripe fruits, showed that flavonols were mostly present in flowers while catechins were highest in unripe fruits and anthocyanins in late fruit maturation stages. A novel MYB TF, PgMYB5-like, was identified, which differs from previously isolated pomegranate TFs by unique C-terminal protein motifs and lack of the amino-acid residues conserved among anthocyanins promoting MYBs. In both pomegranate cultivars the expression of PgMYB5-like was high at flowering stage, while it decreased during fruit ripening. A previously identified bHLH-type TF, PgbHLH, also showed high transcript levels at flowering stage in both cultivars, while it showed a decrease in expression during fruit ripening in cv. Valenciana, but not in cv. Wonderful. Functional analysis of both TFs was performed by agro-infiltration into Nicotiana benthamiana leaves. Plants infiltrated with the PgMYB5-like+PgbHLH combined construct showed a specific and significant accumulation of intermediates of the flavonoid pathway, especially dihydroflavonols, while anthocyanins were not produced. Thus, we propose a role for PgMYB5-like and PgbHLH in the first steps of flavonoid production in flowers and in unripe fruits. The expression patterns of these two TFs may be key in determining the differential flavonoid composition in both flowers and fruits of the pomegranate varieties Wonderful and Valenciana.

MODELACIÓN POR COMPARACIÓN Y ACOPLAMIENTO MULTIMÉRICO DE LA PROTEÍNA EXTERIOR PEQUEÑA DE LA CÁPSIDE DEL BACTERIÓFAGO IME08

The small outer capsid protein plays a stabilizing role in the viral assembly, adhering to the&lt;br /&gt;capsid during the later stages of maturation. This protein acts as glue among adjacent&lt;br /&gt;capsomers, protecting the virus against extreme changes. The small outer capsid protein of the&lt;br /&gt;bacteriophage IME08 was modelled using structural protein homology. A trimeric protein&lt;br /&gt;docking was developed with the best-scored model and important sites of the molecules&lt;br /&gt;interfaces were identified. It was used the Swiss Model platform for developing the protein&lt;br /&gt;structure. Reliability was assessed by the QMEAN, Verify3D and ERRAT indices. The quality of&lt;br /&gt;the whole model was verified by Ramachandran plot and the trimerization model was&lt;br /&gt;performed on the platform ClusPro 2.0 Protein-Protein Docking. The structure obtained has a&lt;br /&gt;reliability estimator QMEANscore4 of 0.769, rating it as a suitable model. The Z-Score QMEAN&lt;br /&gt;value was 0.133, showing that the obtained model is not different from the experimental&lt;br /&gt;structures stored in PDB database. The estimators and the Ramachandran plot evaluated&lt;br /&gt;positively the model. Finally we identified a loop between two secondary structures as an&lt;br /&gt;important site of the interaction of small outer capsid proteins, indicating that from residues 35&lt;br /&gt;to 41 are relevant in the trimerization process.

Calcium Bioavailability of Opuntia ficus-indica Cladodes in an Ovariectomized Rat Model of Postmenopausal Bone Loss.

Osteoporosis is a disease of the skeletal system characterized by low bone mass and bone weakening, which increase the risk of fracture. This disease is associated with menopause because hypoestrogenism induces the maturation and activation of osteoclasts. In addition, a low dietary intake of calcium leads to low bone mineral density and postmenopausal osteoporosis. The objectives of this work were to determine calcium bioavailability of Opuntia ficus-indica cladodes at a late maturity stage and to assess its contribution in improving bone health in an ovariectomized rat model. Two-month-old Wistar female rats (n = 35) were used and distributed in seven experimental groups: (i) control group (Crtl), (ii) sham group (SH), (iii) ovariectomized group (OVX), (iv) ovariectomized group supplemented with calcium citrate (CCa), (v) ovariectomized group supplemented with O. ficus-indica powder (NI), (vi) ovariectomized group supplemented with soluble fiber from O. ficus-indica (FS) and (vii) ovariectomized group supplemented with insoluble fiber from O. ficus-indica (FI). Our results showed that calcium in the soluble fiber of O. ficus-indica is bioavailable and contributes to improve the physical, densitometric, biomechanical and microstructural properties of bones in ovariectomized rats. These findings indicated that O. ficus-indica cladodes at a late maturity stage represent a good source of bioavailable calcium and consumption of these cladodes might be beneficial for the prevention of osteoporosis and other bone diseases.

Influence of pre-harvest foliar spray of fungal culture filtrates on post-harvest biology of date fruit harvested at Khalal stage

Abstract There is a high prevalence of saprophytic fungi in date fruit and date fruit products. Some of these fungi isolated from the infected plants in date palm orchards were identified as Aspergillus niger and Rhizophus oryzae. These fungi cause fruit loss during later stages of maturation and are responsible for severe post-harvest losses of date fruit. They may also deteriorate the overall health of plants. The fungal culture filtrates (FCF) from A. niger (ANFCF) and R. oryzae (ROFCF) were prepared and used as elicitors for the experimentation. These FCFs were foliar sprayed on the date palm plants in the field after the fruit set. Various quality attributes such as weight, firmness and total soluble solids and biochemical properties like total sugars, total proteins, total phenols, ascorbic acid, and antioxidant activity of fresh date fruit (khalal stage) harvested from the FCF treated and untreated plants were studied. The fruit harvested from plants treated with ROFCF showed enhanced levels of total sugar, total proteins, ascorbic acid, and DPPH scavenging activities followed by the fruit from plants treated with ANFCF in comparison to fruit collected from untreated plants. The shelf life of fruit from plants treated with ROFCF and ANFCF increased beyond 14 d at room temperature while the fruit from untreated plants started to deteriorate after 7 d from harvest. The study indicates that the use of fungal culture filtrates as elicitors can help the plant to build up its defense mechanism by elevating the activity of protective enzymes like, Peroxidase (POX), Polyphenol oxidase (PPO) and Phenylalanine ammonia lyase (PAL). It also enhances the growth of plant and improve the quality as well as increases shelf life of fruit.

Thermogenic gas generation from organic-rich shales in the southeastern Say'un-Masila Basin, Yemen as demonstrated by geochemistry, organic petrology, and basin modeling

The current study aimed to explore the gas-generating potential and oil-to-gas conversion in the Madbi oil-source rock system based on data from deep well within the Say'un-Masila Basin using both geochemical and petrological methods as well as basin models. Biomarker results for the bitumen from analyzed shale samples indicate mixed organic matter, with mainly phytoplankton, bacteria, and some terrigenous land plants, deposited under relatively anoxic marine environmental conditions. The terrigenous organic matter, and rich in lipids from phytoplankton and bacteria, suggests Types II and II/III as the original organic matter during deposition. Such findings are not consistent with the significant amounts of vitrinite and inertinite that found under microscope and the low current hydrogen index (HI) values of 43–282 (Types III/IV and III/II kerogen) of the analyzed shale samples. The chemical and optical maturity indicators show that the Madbi shales throughout the studied well section are at different thermal maturity stages, consistent with late-mature stage of the oil window to gas-generation window. Therefore, this high thermal maturation is the critical factor that significantly modifies the original organic matter.Based on the basin models of the single well studied (Ghayl Bin Yumain-01), the initial conversion of kerogen to oil, occurring between the Late Cretaceous and Late Eocene (75–38 Ma), corresponding to peak-oil window (0.70–1.00 Easy %Ro). Furthermore, the oil was expelled during the Late Eocene to Early Oligocene; hence, the late-mature stage of the oil window (1.00–1.30 Easy %Ro) commenced during this time, with transformation ratios (TR) of 50–70%. Subsequently, the cracking of the retained oil into gas has occurred from the Early Oligocene through the present and is attributed to the high thermal maturation of the gas window (>1.30 Easy %Ro), with maximum TRs of 70–97%.

The plant-type phosphoenolpyruvate carboxylase Gmppc2 is developmentally induced in immature soy seeds at the late maturation stage: a potential protein biomarker for seed chemical composition.

Phosphoenolpyruvate carboxylase (PEPC) is a carbon-fixing enzyme with critical roles in seed development. Previously we observed a positive correlation between PEPC activity and protein content in mature seeds among soybean cultivars and varietal differences of PEPC activity in immature seeds, which is concordant with seed protein accumulation. Here, we report a PEPC isoform (Gmppc2) which is preferentially expressed in immature soybean seeds at the late maturation stage. Gmppc2 was co-expressed with enzyme genes involved in starch degradation: α-amylase, hexokinase, and α-glucan phosphorylase. Gmppc2 was developmentally induced in the external seed coats, internal seed coats, hypocotyls, and cotyledons at the late maturation stage. The expression of Gmppc2 protein was negatively regulated by the application of a nitrogen fertilizer, which suppressed nodule formation. These results imply that Gmppc2 is involved in the metabolism of nitrogen originated from nodules into seeds, and Gmppc2 might be applicable as a biomarker of seed protein content.Abbreviations: PEP: phosphoenolpyruvate; PEPC: phosphoenolpyruvate carboxylase; RNA-Seq: RNA sequencing; PCA: principal component analysis; SE: standard error.

Cell seeding simulation on micropatterned islands shows cell density depends on area to perimeter ratio, not on island size or shape

Protein micropatterned substrates have been used to control cell size, shape, and cell–cell contacts, characteristics that influence a range of cell behaviors from early cell differentiation to late stages of maturation. Knowing the initial island cell seeding density is important to interpreting results and understanding downstream cell behavior. While studies routinely report the intended or target cell seeding density, they do not report the actual cell seeding density on the islands. As cells proliferate, differences in initial cell seeding density could compound and may lead to misinterpretation of results. In this work, we present a cell seeding simulation and apply it to 100s of islands with a range of geometries (sizes and shapes) to explore how island cell seeding density relates to the target or unpatterned cell seeding density. We first experimentally validate the simulation and then show that normalized island cell seeding density depends on island size, shape, and spacing, but can be predicted solely from island area to perimeter ratio, A2P, via a power law relationship for a wide range of island geometries. Interestingly, normalized island cell seeding density is the same as the normalized unpatterned cell seeding density for A2P ≥ 17 µm. This simulation will help to design micropatterned substrates and to have more accurate representation of the island cell seeding density at the start of experiments. By knowing the island cell seeding density, we can more easily reproduce results across research groups to understand the roles of cell–cell contact and cell size and shape on cell behavior. Statement of SignificanceWe present a cell seeding simulation on protein-micropatterned substrates and use it to simulate seeding across 100s of island geometries (size, shape, and spacing) covering two orders of magnitude in size. The simulation shows that island cell density varies significantly with island geometry compared to the target seeding density. However, island cell density can be predicted from one geometric parameter – the island's area to perimeter ratio. Results will help direct researchers on how to achieve uniform cell density across all island geometries. Since cell density and island shape both influence cell behaviors, such as differentiation, this simulation may help to isolate these factors, facilitate micropatterned substrate design, and provide a mechanism for more reproduceable results across studies.

Kv4.1, a Key Ion Channel For Low Frequency Firing of Dentate Granule Cells, Is Crucial for Pattern Separation.

The dentate gyrus (DG) in the hippocampus may play key roles in remembering distinct episodes through pattern separation, which may be subserved by the sparse firing properties of granule cells (GCs) in the DG. Low intrinsic excitability is characteristic of mature GCs, but ion channel mechanisms are not fully understood. Here, we investigated ionic channel mechanisms for firing frequency regulation in hippocampal GCs using male and female mice, and identified Kv4.1 as a key player. Immunofluorescence analysis showed that Kv4.1 was preferentially expressed in the DG, and its expression level determined by Western blot analysis was higher at 8-week than 3-week-old mice, suggesting a developmental regulation of Kv4.1 expression. With respect to firing frequency, GCs are categorized into two distinctive groups: low-frequency (LF) and high-frequency (HF) firing GCs. Input resistance (Rin) of most LF-GCs is lower than 200 MΩ, suggesting that LF-GCs are fully mature GCs. Kv4.1 channel inhibition by intracellular perfusion of Kv4.1 antibody increased firing rates and gain of the input-output relationship selectively in LF-GCs with no significant effect on resting membrane potential and Rin, but had no effect in HF-GCs. Importantly, mature GCs from mice depleted of Kv4.1 transcripts in the DG showed increased firing frequency, and these mice showed an impairment in contextual discrimination task. Our findings suggest that Kv4.1 expression occurring at late stage of GC maturation is essential for low excitability of DG networks and thereby contributes to pattern separation.SIGNIFICANCE STATEMENT The sparse activity of dentate granule cells (GCs), which is essential for pattern separation, is supported by high inhibitory inputs and low intrinsic excitability of GCs. Low excitability of GCs is thought to be attributable to a high K+ conductance at resting membrane potentials, but this study identifies Kv4.1, a depolarization-activated K+ channel, as a key ion channel that regulates firing of GCs without affecting resting membrane potentials. Kv4.1 expression is developmentally regulated and Kv4.1 currents are detected only in mature GCs that show low-frequency firing, but not in less mature high-frequency firing GCs. Furthermore, mice depleted of Kv4.1 transcripts in the dentate gyrus show impaired pattern separation, suggesting that Kv4.1 is crucial for sparse coding and pattern separation.

Perillyl alcohol and perillic acid exert efficient action upon HSV-1 maturation and release of infective virus.

Infection by herpes simplex type-1 virus (HSV-1) causes several pathological processes, including cutaneous, oral and genital infections, fatal encephalitis and cognitive dysfunction due to grey matter loss. Acyclovir is the reference compound used as HSV-1 antiviral therapy. However, with the emergence of HSV-resistant strains to current antiviral drugs, development of new antiviral agents with distinct modes of action is urgently needed. In this study, we examined the mechanism of action of monoterpenes perillyl alcohol (POH) and perillic acid (PA) upon in vitro replication of HSV-1 KOS wild-type and the syn-mutant 17+ strain on Vero cells by plaque assay. The cytotoxicity of POH and PA was measured by MTT assay and indicated that both compounds had high anti-HSV-1 activities in a concentration range that was not toxic for Vero cells. In addition, PCR analysis showed that POH and PA did not inhibit viral genome replication, but rather the release of infective virion particles from Vero cells. Such findings suggest that POH and PA exert action upon late stages of HSV-1 maturation, therefore, indicating a promising perspective to its application in clinical investigation as effective anti-HSV-1 therapy preventing intermittent reactivation and progressive grey matter loss.

Autoradiographic study of iron transport in rat incisor enamel.

An autoradiographic study using 55Fe was performed to investigate the distribution of iron in the ameloblasts and enamel of rat incisors. The study of methodological problems of 55Fe autoradiography revealed that in the undecalcified sections, the radiation by 55Fe within the ameloblasts and pigmented enamel produced grain scattering over the facing enamel surface and ameloblasts, respectively. The findings indicate that the autoradiographic observation of the enamel surface should be made using the incisors freed from the enamel organ and that the observation of the ameloblasts should be done in the region other than the zone of enamel pigmentation. After the 55Fe injection, 55Fe incorporation into the ameloblasts was observed in the maturation stage, reaching the maximum at 24 hours. The peak of 55Fe distribution in the ameloblasts moved from the early stage to the later stage of maturation between 24 hours and 7 days after the injection. At 3 and 7 days after the 55Fe injection, 55Fe was deposited markedly on the enamel surface at the end of maturation where the enamel pigmentation occurs. The present study established the utility of 55Fe autoradiography when applied on the undecalcified section of rat incisors and it was demonstrated that iron is incorporated into the maturation ameloblasts and secreted onto the enamel surface at the end of maturation.

Expression of a Chromoplast-Specific Lycopene β-Cyclase Gene (CYC-B) Is Implicated in Carotenoid Accumulation and Coloration in the Loquat.

Carotenoids are the principal pigments in the loquat. Although the metabolic pathway of plant carotenoids has been extensively investigated, few studies have been explored the regulatory mechanisms of loquat carotenoids because knowledge of the loquat genome is incomplete. The chromoplast-specific lycopene β-cyclase gene (CYC-B) could catalyze cyclization of lycopene to β-carotene. In this study, the differential accumulation patterns of loquat with different colors were analyzed and virus-induced gene silencing (VIGS) was utilized in order to verify CYC-B gene function. Using a cloning strategy of homologous genes, a CYC-B gene orthologue was successfully identified from the loquat. At a later stage of maturation, CYC-B gene expression and carotenoids concentrations in the ‘Dawuxing’ variety were higher than in ‘Chuannong 1-5-9′, possibly leading to the difference in pulp coloration of loquat. Interference of CYC-B gene expression in the loquat demonstrated clear visual changes. The green color in negative control fruits became yellow, while TRV2-CYC-B silenced fruits remained green. CYC-B gene expression and total carotenoid content in the pulp decreased by 32.5% and 44.1%, respectively. Furthermore, multiple key genes in the carotenoid metabolic pathway synergistically responded to downregulation of CYC-B gene expression. In summary, we provide direct evidences that CYC-B gene is involved in carotenoid accumulation and coloration in the loquat.

Pattern analysis suggests that phosphoenolpyruvate carboxylase in maturing soybean seeds promotes the accumulation of protein.

The protein and oil contents in soybean seeds are major factors in seed quality. Seed proteins and oils are synthesized from sucrose and nitrogenous compounds transported into maturing seeds. In this study, we compared changes in the activity of phosphoenolpyruvate carboxylase (PEPC) and the accumulation profiles of protein and oil in maturing seeds of two soybean cultivars, which exhibit different protein and oil contents in seeds, to determine the interrelationships of them. A principal component analysis indicated a concordance of seed PEPC activity with the protein content, but did not with the oil content. PEPC activity per seed was highest in the late maturation stage, when the physiological status of the vegetative organs drastically changed. The high-protein cultivar had higher PEPC activity compared to the low-protein cultivar. These results highlight the biological role of PEPC in the synthesis of protein, therefore it was implied that PEPC could be a biomarker in soybean breeding.Abbreviations: ANOVA: analysis of variance; DS: developmental stage; DW: dry weight; FW: fresh weight; NIR: near infrared; PEP(C): phosphoenolpyruvate (carboxylase); PC(A): principal component (analysis); S.E.: standard error; WC: water content.

Electron Tomography Analysis of Thylakoid Assembly and Fission in Chloroplasts of a Single-Cell C4 plant, Bienertia sinuspersici

Bienertia sinuspersici is a single-cell C4 plant species of which chlorenchyma cells have two distinct groups of chloroplasts spatially segregated in the cytoplasm. The central vacuole encloses most chloroplasts at the cell center and confines the rest of the chloroplasts near the plasma membrane. Young chlorenchyma cells, however, do not have large vacuoles and their chloroplasts are homogenous. Therefore, maturing Bienertia chlorenchyma cells provide a unique opportunity to investigate chloroplast proliferation in the central cluster and the remodeling of chloroplasts that have been displaced by the vacuole to the cell periphery. Chloroplast numbers and sizes increased, more notably, during later stages of maturation than the early stages. Electron tomography analyses indicated that chloroplast enlargement is sustained by thylakoid growth and that invaginations from the inner envelope membrane contributed to thylakoid assembly. Grana stacks acquired more layers, differentiating them from stroma thylakoids as central chloroplasts matured. In peripheral chloroplasts, however, grana stacks stretched out to a degree that the distinction between grana stacks and stroma thylakoids was obscured. In central chloroplasts undergoing division, thylakoids inside the cleavage furrow were kinked and severed. Grana stacks in the division zone were disrupted, and large complexes in their membranes were dislocated, suggesting the existence of a thylakoid fission machinery.