scholarly journals Patterns in evolutionary origins of heme, chlorophyll a and isopentenyl diphosphate biosynthetic pathways suggest non-photosynthetic periods prior to plastid replacements in dinoflagellates.

Author(s):  
Eriko Matsuo ◽  
Yuji Inagaki

Background: The ancestral dinoflagellate most likely established a peridinin-containing plastid, which has been inherited to the extant photosynthetic descendants. However, kareniacean dinoflagellates and Lepidodinium species were known to bear “non-canonical” plastids lacking peridinin, which were established through a haptophyte and a green algal endosymbioses, respectively. For plastid function and maintenance, the aforementioned dinoflagellates were known to use nucleus-encoded proteins vertically inherited from the ancestral dinoflagellates (vertically inherited- or VI-type), and those acquired from non-dinoflagellate organisms including the endosymbionts. These observations indicated that the proteomes of the non-canonical plastids derived from a haptophyte and a green alga were modified by “exogenous” genes acquired from non-dinoflagellate organisms. However, there was no systematic evaluation addressing how “exogenous” genes reshaped individual metabolic pathways localized in a non-canonical plastid. Results: In this study, we surveyed transcriptomic data from two kareniacean species [Karenia (Ke.) brevis and Karlodinium (Kl.) veneficum] and Lepidodinium chlorophorum, and identified proteins involved in three plastid metabolic pathways synthesizing chlorophyll a (Chl a), heme and isopentenyl diphosphate (IPP). The origins of the individual proteins of our interest were investigated, and assessed how the three pathways were modified before and after the algal endosymbioses, which gave rise to the current non-canonical plastids. We observed a clear difference in the contribution of VI-type proteins across the three pathways. In both Ke. brevis/Kl. veneficum and L. chlorophorum, we observed a substantial contribution of VI-type proteins to the IPP and heme biosyntheses. In sharp contrast, VI-type protein was barely detected in the Chl a biosynthesis in the three dinoflagellates. Discussion: Pioneering works hypothesized that the ancestral kareniacean species had lost the photosynthetic activity prior to haptophyte endosymbiosis. The absence of VI-type proteins in the Chl a biosynthetic pathway in Ke. brevis or Kl. veneficum is in good agreement with the putative non-photosynthetic nature proposed for their ancestor. The dominance of proteins with haptophyte origin in the Ke. brevis/Kl. veneficum pathway suggests that their ancestor rebuilt the particular pathway by genes acquired from the endosymbiont. Likewise, we here propose that the ancestral Lepidodinium likely experienced a non-photosynthetic period and discarded the Chl a biosynthetic pathway mostly prior to the green algal endosymbiosis. In the subsequent evolution, L. chlorophorum rebuilt the pathway by genes transferred from phylogenetically diverse organisms, rather than the green algal endosymbiont. We explore the reasons why green algal genes were barely utilized to reconstruct the L. chlorophorum pathway.

2018 ◽  
Author(s):  
Eriko Matsuo ◽  
Yuji Inagaki

Background: The ancestral dinoflagellate most likely established a peridinin-containing plastid, which has been inherited to the extant photosynthetic descendants. However, kareniacean dinoflagellates and Lepidodinium species were known to bear “non-canonical” plastids lacking peridinin, which were established through a haptophyte and a green algal endosymbioses, respectively. For plastid function and maintenance, the aforementioned dinoflagellates were known to use nucleus-encoded proteins vertically inherited from the ancestral dinoflagellates (vertically inherited- or VI-type), and those acquired from non-dinoflagellate organisms including the endosymbionts. These observations indicated that the proteomes of the non-canonical plastids derived from a haptophyte and a green alga were modified by “exogenous” genes acquired from non-dinoflagellate organisms. However, there was no systematic evaluation addressing how “exogenous” genes reshaped individual metabolic pathways localized in a non-canonical plastid. Results: In this study, we surveyed transcriptomic data from two kareniacean species [Karenia (Ke.) brevis and Karlodinium (Kl.) veneficum] and Lepidodinium chlorophorum, and identified proteins involved in three plastid metabolic pathways synthesizing chlorophyll a (Chl a), heme and isopentenyl diphosphate (IPP). The origins of the individual proteins of our interest were investigated, and assessed how the three pathways were modified before and after the algal endosymbioses, which gave rise to the current non-canonical plastids. We observed a clear difference in the contribution of VI-type proteins across the three pathways. In both Ke. brevis/Kl. veneficum and L. chlorophorum, we observed a substantial contribution of VI-type proteins to the IPP and heme biosyntheses. In sharp contrast, VI-type protein was barely detected in the Chl a biosynthesis in the three dinoflagellates. Discussion: Pioneering works hypothesized that the ancestral kareniacean species had lost the photosynthetic activity prior to haptophyte endosymbiosis. The absence of VI-type proteins in the Chl a biosynthetic pathway in Ke. brevis or Kl. veneficum is in good agreement with the putative non-photosynthetic nature proposed for their ancestor. The dominance of proteins with haptophyte origin in the Ke. brevis/Kl. veneficum pathway suggests that their ancestor rebuilt the particular pathway by genes acquired from the endosymbiont. Likewise, we here propose that the ancestral Lepidodinium likely experienced a non-photosynthetic period and discarded the Chl a biosynthetic pathway mostly prior to the green algal endosymbiosis. In the subsequent evolution, L. chlorophorum rebuilt the pathway by genes transferred from phylogenetically diverse organisms, rather than the green algal endosymbiont. We explore the reasons why green algal genes were barely utilized to reconstruct the L. chlorophorum pathway.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5345 ◽  
Author(s):  
Eriko Matsuo ◽  
Yuji Inagaki

Background The ancestral dinoflagellate most likely established a peridinin-containing plastid, which have been inherited in the extant photosynthetic descendants. However, kareniacean dinoflagellates and Lepidodinium species were known to bear “non-canonical” plastids lacking peridinin, which were established through haptophyte and green algal endosymbioses, respectively. For plastid function and maintenance, the aforementioned dinoflagellates were known to use nucleus-encoded proteins vertically inherited from the ancestral dinoflagellates (vertically inherited- or VI-type), and those acquired from non-dinoflagellate organisms (including the endosymbiont). These observations indicated that the proteomes of the non-canonical plastids derived from a haptophyte and a green alga were modified by “exogenous” genes acquired from non-dinoflagellate organisms. However, there was no systematic evaluation addressing how “exogenous” genes reshaped individual metabolic pathways localized in a non-canonical plastid. Results In this study, we surveyed transcriptomic data from two kareniacean species (Karenia brevis and Karlodinium veneficum) and Lepidodinium chlorophorum, and identified proteins involved in three plastid metabolic pathways synthesizing chlorophyll a (Chl a), heme and isoprene. The origins of the individual proteins of our interest were investigated, and we assessed how the three pathways were modified before and after the algal endosymbioses, which gave rise to the current non-canonical plastids. We observed a clear difference in the contribution of VI-type proteins across the three pathways. In both Karenia/Karlodinium and Lepidodinium, we observed a substantial contribution of VI-type proteins to the isoprene and heme biosynthesises. In sharp contrast, VI-type protein was barely detected in the Chl a biosynthesis in the three dinoflagellates. Discussion Pioneering works hypothesized that the ancestral kareniacean species had lost the photosynthetic activity prior to haptophyte endosymbiosis. The absence of VI-type proteins in the Chl a biosynthetic pathway in Karenia or Karlodinium is in good agreement with the putative non-photosynthetic nature proposed for their ancestor. The dominance of proteins with haptophyte origin in the Karenia/Karlodinium pathway suggests that their ancestor rebuilt the particular pathway by genes acquired from the endosymbiont. Likewise, we here propose that the ancestral Lepidodinium likely experienced a non-photosynthetic period and discarded the entire Chl a biosynthetic pathway prior to the green algal endosymbiosis. Nevertheless, Lepidodinium rebuilt the pathway by genes transferred from phylogenetically diverse organisms, rather than the green algal endosymbiont. We explore the reasons why green algal genes were barely utilized to reconstruct the Lepidodinium pathway.


2017 ◽  
Author(s):  
Eriko Matsuo ◽  
Yuji Inagaki

Background: The ancestral dinoflagellate most likely established a peridinin-containing plastid, which have been inherited to the extant photosynthetic descendants. However, kareniacean dinoflagellates and Lepidodinium species were known to bear “non-canonical” plastids lacking peridinin, which were established through haptophyte and a green algal endosymbioses, respectively. For plastid function and maintenance, the aforementioned dinoflagellates were known to use nucleus-encoded proteins vertically inherited from the ancestral dinoflagellates (vertically inherited- or VI-type), and those acquired from non-dinoflagellate organisms (including the endosymbiont). These observations indicated that the proteomes of the non-canonical plastids derived from a haptophyte and a green alga were modified by “exogenous” genes acquired from non-dinoflagellate organisms. However, there was no systematic evaluation addressing how “exogenous” genes reshaped individual metabolic pathways localized in a non-canonical plastid. Results: In this study, we surveyed transcriptomic data from two kareniacean species (Karenia brevis and Karlodinium veneficum) and Lepidodinium chlorophorum, and identified proteins involved in three plastid metabolic pathways synthesizing chlorophyll a (Chl a), heme and isoprene. The origins of the individual proteins of our interest were investigated, and assessed how the three pathways were modified before and after the algal endosymbioses, which gave rise to the current non-canonical plastids. We observed a clear difference in the contribution of VI-type proteins across the three pathways. In both Karenia/Karlodinium and Lepidodinium, we observed a substantial contribution of VI-type proteins to the isoprene and heme biosynthesises. In sharp contrast, VI-type protein was barely detected in the Chl a biosynthesis in the three dinoflagellates. Discussion: Pioneering works hypothesized that the ancestral kareniacean species had lost the photosynthetic activity prior to haptophyte endosymbiosis. The absence of VI-type proteins in the Chl a biosynthetic pathway in Karenia or Karlodinium is in good agreement with the putative non-photosynthetic nature proposed for their ancestor. The dominance of proteins with haptophyte origin in the Karenia/Karlodinium pathway suggests that their ancestor rebuilt the particular pathway by genes acquired from the endosymbiont. Likewise, we here propose that the ancestral Lepidodinium likely experienced a non-photosynthetic period and discarded the entire Chl a biosynthetic pathway prior to the green algal endosymbiosis. Nevertheless, Lepidodinium rebuilt the pathway by genes transferred from phylogenetically diverse organisms, rather than the green algal endosymbiont. We explore the reasons why green algal genes were barely utilized to reconstruct the Lepidodinium pathway.


2019 ◽  
Author(s):  
Shane Timmons

Encouraging consumers to switch to lower-rate mortgages is important both for the individual consumer’s finances and for functioning competitive markets, but switching rates are low. Given the complexity of mortgages, one potential regulatory intervention that may increase switching rates is to provide independent advice on how to select good mortgage products and how to navigate the switching process. Working with a government consumer protection agency, we conducted an experiment with mortgage-holders to test whether such advice alters perceptions of switching. The experiment tested how (i) the attributes of the offer, (ii) perceptions about the switching process, (iii) individual feelings of competence and (iv) comprehension of the product affect willingness to switch to better offers, both before and after reading the official advice. The advice made consumers more sensitive to interest rate decreases, especially at longer terms. It also increased consumers’ confidence in their ability to select good offers. Overall, the findings imply that advice from policymakers can change perceptions and increase switching rates. Moreover, the experiment demonstrates how lab studies can contribute to behaviourally-informed policy development.


2003 ◽  
Vol 128 (1) ◽  
pp. 17-26 ◽  
Author(s):  
David J. Kay ◽  
Richard M. Rosenfeld

OBJECTIVE: The goal was to validate the SN-5 survey as a measure of longitudinal change in health-related quality of life (HRQoL) for children with persistent sinonasal symptoms. DESIGN AND SETTING: We conducted a before and after study of 85 children aged 2 to 12 years in a metropolitan pediatric otolaryngology practice. Caregivers completed the SN-5 survey at entry and at least 4 weeks later. The survey included 5 symptom-cluster items covering the domains of sinus infection, nasal obstruction, allergy symptoms, emotional distress, and activity limitations. RESULTS: Good test-retest reliability ( R = 0.70) was obtained for the overall SN-5 score and the individual survey items ( R ≥ 0.58). The mean baseline SN-5 score was 3.8 (SD, 1.0) of a maximum of 7.0, with higher scores indicating poorer HRQoL. All SN-5 items had adequate correlation ( R ≥ 0.36) with external constructs. The mean change in SN-5 score after routine clinical care was 0.88 (SD, 1.19) with an effect size of 0.74 indicating good responsiveness to longitudinal change. The change scores correlated appropriately with changes in related external constructs ( R ≥ 0.42). CONCLUSIONS: The SN-5 is a valid, reliable, and responsive measure of HRQoL for children with persistent sinonasal symptoms, suitable for use in outcomes studies and routine clinical care.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Linda T. Betz ◽  
◽  
Nora Penzel ◽  
Lana Kambeitz-Ilankovic ◽  
Marlene Rosen ◽  
...  

AbstractRecent life events have been implicated in the onset and progression of psychosis. However, psychological processes that account for the association are yet to be fully understood. Using a network approach, we aimed to identify pathways linking recent life events and symptoms observed in psychosis. Based on previous literature, we hypothesized that general symptoms would mediate between recent life events and psychotic symptoms. We analyzed baseline data of patients at clinical high risk for psychosis and with recent-onset psychosis (n = 547) from the Personalised Prognostic Tools for Early Psychosis Management (PRONIA) study. In a network analysis, we modeled links between the burden of recent life events and all individual symptoms of the Positive and Negative Syndrome Scale before and after controlling for childhood trauma. To investigate the longitudinal associations between burden of recent life events and symptoms, we analyzed multiwave panel data from seven timepoints up to month 18. Corroborating our hypothesis, burden of recent life events was connected to positive and negative symptoms through general psychopathology, specifically depression, guilt feelings, anxiety and tension, even after controlling for childhood trauma. Longitudinal modeling indicated that on average, burden of recent life events preceded general psychopathology in the individual. In line with the theory of an affective pathway to psychosis, recent life events may lead to psychotic symptoms via heightened emotional distress. Life events may be one driving force of unspecific, general psychopathology described as characteristic of early phases of the psychosis spectrum, offering promising avenues for interventions.


2021 ◽  
Vol 47 (2) ◽  
pp. 1-28
Author(s):  
Goran Flegar ◽  
Hartwig Anzt ◽  
Terry Cojean ◽  
Enrique S. Quintana-Ortí

The use of mixed precision in numerical algorithms is a promising strategy for accelerating scientific applications. In particular, the adoption of specialized hardware and data formats for low-precision arithmetic in high-end GPUs (graphics processing units) has motivated numerous efforts aiming at carefully reducing the working precision in order to speed up the computations. For algorithms whose performance is bound by the memory bandwidth, the idea of compressing its data before (and after) memory accesses has received considerable attention. One idea is to store an approximate operator–like a preconditioner–in lower than working precision hopefully without impacting the algorithm output. We realize the first high-performance implementation of an adaptive precision block-Jacobi preconditioner which selects the precision format used to store the preconditioner data on-the-fly, taking into account the numerical properties of the individual preconditioner blocks. We implement the adaptive block-Jacobi preconditioner as production-ready functionality in the Ginkgo linear algebra library, considering not only the precision formats that are part of the IEEE standard, but also customized formats which optimize the length of the exponent and significand to the characteristics of the preconditioner blocks. Experiments run on a state-of-the-art GPU accelerator show that our implementation offers attractive runtime savings.


2021 ◽  
Vol 11 (7) ◽  
pp. 2917
Author(s):  
Madalina Rabung ◽  
Melanie Kopp ◽  
Antal Gasparics ◽  
Gábor Vértesy ◽  
Ildikó Szenthe ◽  
...  

The embrittlement of two types of nuclear pressure vessel steel, 15Kh2NMFA and A508 Cl.2, was studied using two different methods of magnetic nondestructive testing: micromagnetic multiparameter microstructure and stress analysis (3MA-X8) and magnetic adaptive testing (MAT). The microstructure and mechanical properties of reactor pressure vessel (RPV) materials are modified due to neutron irradiation; this material degradation can be characterized using magnetic methods. For the first time, the progressive change in material properties due to neutron irradiation was investigated on the same specimens, before and after neutron irradiation. A correlation was found between magnetic characteristics and neutron-irradiation-induced damage, regardless of the type of material or the applied measurement technique. The results of the individual micromagnetic measurements proved their suitability for characterizing the degradation of RPV steel caused by simulated operating conditions. A calibration/training procedure was applied on the merged outcome of both testing methods, producing excellent results in predicting transition temperature, yield strength, and mechanical hardness for both materials.


2020 ◽  
Vol 13 (1) ◽  
pp. 79-113
Author(s):  
Farrah Neumann ◽  
Matthew Kanwit

AbstractSince many linguistic structures are variable (i. e. conveyed by multiple forms), building a second-language grammar critically involves developing sociolinguistic competence (Canale and Swain. 1980. Theoretical bases of communicative approaches to second language teaching and testing. Applied Linguistics 1(1). 1–47), including knowledge of contexts in which to use one form over another (Bayley and Langman. 2004. Variation in the group and the individual: Evidence from second language acquisition. International Review of Applied Linguistics in Language Teaching 42(4). 303–318). Consequently, researchers interested in such competence have increasingly analyzed the study-abroad context to gauge learners’ ability to approximate local norms following a stay abroad, due to the quality and quantity of input to which learners may gain access (Lafford. 2006. The effects of study abroad vs. classroom contexts on Spanish SLA: Old assumptions, new insights and future research directions. In Carol Klee & Timothy Face (eds.), Selected proceedings of the 7th conference on the acquisition of Spanish and Portuguese as first and second languages, 1–25. Somerville, MA: Cascadilla Proceedings Project). Nevertheless, the present study is the first to examine native or learner variation between imperative (e. g. ven ‘come’) and optative Spanish commands (e. g. que vengas ‘come’). We first performed a corpus analysis to determine the linguistic factors to manipulate in a contextualized task, which elicited commands from learners before and after four weeks abroad in Alcalá de Henares, Spain. Their overall rates of selection and predictive factors were compared to local native speakers (NSs) and a control group of at-home learners.Results revealed that the abroad learners more closely approached NS rates of selection following the stay abroad. Nonetheless, for both learner groups conditioning by independent variables only partially approximated the NS system, which was more complex than previously suggested.


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