1
|
Cecchin M, Simicevic J, Chaput L, Hernandez Gil M, Girolomoni L, Cazzaniga S, Remacle C, Hoeng J, Ivanov NV, Titz B, Ballottari M. Acclimation strategies of the green alga Chlorella vulgaris to different light regimes revealed by physiological and comparative proteomic analyses. J Exp Bot 2023; 74:4540-4558. [PMID: 37155956 DOI: 10.1093/jxb/erad170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/05/2023] [Indexed: 05/10/2023]
Abstract
Acclimation to different light regimes is at the basis of survival for photosynthetic organisms, regardless of their evolutionary origin. Previous research efforts largely focused on acclimation events occurring at the level of the photosynthetic apparatus and often highlighted species-specific mechanisms. Here, we investigated the consequences of acclimation to different irradiances in Chlorella vulgaris, a green alga that is one of the most promising species for industrial application, focusing on both photosynthetic and mitochondrial activities. Moreover, proteomic analysis of cells acclimated to high light (HL) or low light (LL) allowed identification of the main targets of acclimation in terms of differentially expressed proteins. The results obtained demonstrate photosynthetic adaptation to HL versus LL that was only partially consistent with previous findings in Chlamydomonas reinhardtii, a model organism for green algae, but in many cases similar to vascular plant acclimation events. Increased mitochondrial respiration measured in HL-acclimated cells mainly relied on alternative oxidative pathway dissipating the excessive reducing power produced due to enhanced carbon flow. Finally, proteins involved in cell metabolism, intracellular transport, gene expression, and signaling-including a heliorhodopsin homolog-were identified as strongly differentially expressed in HL versus LL, suggesting their key roles in acclimation to different light regimes.
Collapse
Affiliation(s)
- Michela Cecchin
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Jovan Simicevic
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland
| | - Louise Chaput
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland
| | - Manuel Hernandez Gil
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland
| | - Laura Girolomoni
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Stefano Cazzaniga
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Claire Remacle
- Genetics and Physiology of Microalgae, InBios/Phytosystems Research Unit, University of Liège, 4000 Liège, Belgium
| | - Julia Hoeng
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland
| | - Nikolai V Ivanov
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland
| | - Bjoern Titz
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland
| | - Matteo Ballottari
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
| |
Collapse
|
2
|
Marcolungo L, Vincenzi L, Ballottari M, Cecchin M, Cosentino E, Mignani T, Limongi A, Ferraris I, Orlandi M, Rossato M, Delledonne M. Structural Refinement by Direct Mapping Reveals Assembly Inconsistencies near Hi-C Junctions. Plants (Basel) 2023; 12:320. [PMID: 36679033 PMCID: PMC9861903 DOI: 10.3390/plants12020320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/22/2022] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
High-throughput chromosome conformation capture (Hi-C) is widely used for scaffolding in de novo assembly because it produces highly contiguous genomes, but its indirect statistical approach can introduce connection errors. We employed optical mapping (Bionano Genomics) as an orthogonal scaffolding technology to assess the structural solidity of Hi-C reconstructed scaffolds. Optical maps were used to assess the correctness of five de novo genome assemblies based on long-read sequencing for contig generation and Hi-C for scaffolding. Hundreds of inconsistencies were found between the reconstructions generated using the Hi-C and optical mapping approaches. Manual inspection, exploiting raw long-read sequencing data and optical maps, confirmed that several of these conflicts were derived from Hi-C joining errors. Such misjoins were widespread, involved the connection of both small and large contigs, and even overlapped annotated genes. We conclude that the integration of optical mapping data after, not before, Hi-C-based scaffolding, improves the quality of the assembly and limits reconstruction errors by highlighting misjoins that can then be subjected to further investigation.
Collapse
Affiliation(s)
- Luca Marcolungo
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Leonardo Vincenzi
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Matteo Ballottari
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Michela Cecchin
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | | | - Thomas Mignani
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Antonina Limongi
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Irene Ferraris
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Matteo Orlandi
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Marzia Rossato
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
- Genartis srl, Via IV Novembre 24, 37126 Verona, Italy
| | - Massimo Delledonne
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
- Genartis srl, Via IV Novembre 24, 37126 Verona, Italy
| |
Collapse
|
3
|
Cecchin M, Cazzaniga S, Martini F, Paltrinieri S, Bossi S, Maffei ME, Ballottari M. Astaxanthin and eicosapentaenoic acid production by S4, a new mutant strain of Nannochloropsis gaditana. Microb Cell Fact 2022; 21:117. [PMID: 35710482 PMCID: PMC9204945 DOI: 10.1186/s12934-022-01847-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 06/01/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Astaxanthin is a ketocarotenoid with high antioxidant power used in different fields as healthcare, food/feed supplementation and as pigmenting agent in aquaculture. Primary producers of astaxanthin are some species of microalgae, unicellular photosynthetic organisms, as Haematococcus lacustris. Astaxanthin production by cultivation of Haematococcus lacustris is costly due to low biomass productivity, high risk of contamination and the requirement of downstream extraction processes, causing an extremely high price on the market. Some microalgae species are also primary producers of omega-3 fatty acids, essential nutrients for humans, being related to cardiovascular wellness, and required for visual and cognitive development. One of the main well-known producers of omega-3 fatty eicosapentaenoic acid (EPA) is the marine microalga Nannochloropsis gaditana (named also Microchloropsis gaditana): this species has been already approved by the Food and Drug Administration (FDA) for human consumption and it is characterized by a fast grow phenotype. RESULTS Here we obtained by chemical mutagenesis a Nannochloropsis gaditana mutant strain, called S4, characterized by increased carotenoid to chlorophyll ratio. S4 strain showed improved photosynthetic activity, increased lipid productivity and increased ketocarotenoids accumulation, producing not only canthaxanthin but also astaxanthin, usually found only in traces in the WT strain. Ketocarotenoids produced in S4 strain were extractible in different organic solvents, with the highest efficiency observed upon microwaves pre-treatment followed by methanol extraction. By cultivation of S4 strain at different irradiances it was possible to produce up to 1.3 and 5.2 mgL-1 day-1 of ketocarotenoids and EPA respectively, in a single cultivation phase, even in absence of stressing conditions. Genome sequencing of S4 strain allowed to identify 199 single nucleotide polymorphisms (SNP): among the mutated genes, mutations in a carotenoid oxygenase gene and in a glutamate synthase gene could explain the different carotenoids content and the lower chlorophylls content, respectively. CONCLUSIONS By chemical mutagenesis and selection of strain with increased carotenoids to chlorophyll ratio it was possible to isolate a new Nannochloropsis gaditana strain, called S4 strain, characterized by increased lipids and ketocarotenoids accumulation. S4 strain can thus be considered as novel platform for ketocarotenoids and EPA production for different industrial applications.
Collapse
Affiliation(s)
- Michela Cecchin
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Stefano Cazzaniga
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Flavio Martini
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Stefania Paltrinieri
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Simone Bossi
- Dipartimento di Scienze della Vita e Biologia dei Sistemi, Unità di Fisiologia Vegetale, Università di Torino, Via Quarello 15/a, 10135, Turin, Italy
| | - Massimo E Maffei
- Dipartimento di Scienze della Vita e Biologia dei Sistemi, Unità di Fisiologia Vegetale, Università di Torino, Via Quarello 15/a, 10135, Turin, Italy
| | - Matteo Ballottari
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134, Verona, Italy.
| |
Collapse
|
4
|
Cecchin M, Paloschi M, Busnardo G, Cazzaniga S, Cuine S, Li‐Beisson Y, Wobbe L, Ballottari M. CO 2 supply modulates lipid remodelling, photosynthetic and respiratory activities in Chlorella species. Plant Cell Environ 2021; 44:2987-3001. [PMID: 33931891 PMCID: PMC8453743 DOI: 10.1111/pce.14074] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 04/20/2021] [Accepted: 04/23/2021] [Indexed: 05/28/2023]
Abstract
Microalgae represent a potential solution to reduce CO2 emission exploiting their photosynthetic activity. Here, the physiologic and metabolic responses at the base of CO2 assimilation were investigated in conditions of high or low CO2 availability in two of the most promising algae species for industrial cultivation, Chlorella sorokiniana and Chlorella vulgaris. In both species, high CO2 availability increased biomass accumulation with specific increase of triacylglycerols in C. vulgaris and polar lipids and proteins in C. sorokiniana. Moreover, high CO2 availability caused only in C. vulgaris a reduced NAD(P)H/NADP+ ratio and reduced mitochondrial respiration, suggesting a CO2 dependent increase of reducing power consumption in the chloroplast, which in turn influences the redox state of the mitochondria. Several rearrangements of the photosynthetic machinery were observed in both species, differing from those described for the model organism Chlamydomonas reinhardtii, where adaptation to carbon availability is mainly controlled by the translational repressor NAB1. NAB1 homologous protein could be identified only in C. vulgaris but lacked the regulation mechanisms previously described in C. reinhardtii. Acclimation strategies to cope with a fluctuating inorganic carbon supply are thus diverse among green microalgae, and these results suggest new biotechnological strategies to boost CO2 fixation.
Collapse
Affiliation(s)
- Michela Cecchin
- Dipartimento di BiotecnologieUniversità di VeronaVeronaItaly
| | - Matteo Paloschi
- Dipartimento di BiotecnologieUniversità di VeronaVeronaItaly
| | | | | | - Stephan Cuine
- Aix‐Marseille Univ., CEA, CNRSInstitute of Biosciences and Biotechnologies of Aix‐Marseille, UMR7265, CEA CadaracheSaint‐Paul‐lez DuranceFrance
| | - Yonghua Li‐Beisson
- Aix‐Marseille Univ., CEA, CNRSInstitute of Biosciences and Biotechnologies of Aix‐Marseille, UMR7265, CEA CadaracheSaint‐Paul‐lez DuranceFrance
| | - Lutz Wobbe
- Bielefeld UniversityCenter for Biotechnology (CeBiTec), Faculty of BiologyBielefeldGermany
| | | |
Collapse
|
5
|
Cecchin M, Jeong J, Son W, Kim M, Park S, Zuliani L, Cazzaniga S, Pompa A, Young Kang C, Bae S, Ballottari M, Jin E. LPA2 protein is involved in photosystem II assembly in Chlamydomonas reinhardtii. Plant J 2021; 107:1648-1662. [PMID: 34218480 PMCID: PMC8518032 DOI: 10.1111/tpj.15405] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 06/23/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
Photosynthetic eukaryotes require the proper assembly of photosystem II (PSII) in order to strip electrons from water and fuel carbon fixation reactions. In Arabidopsis thaliana, one of the PSII subunits (CP43/PsbC) was suggested to be assembled into the PSII complex via its interaction with an auxiliary protein called Low PSII Accumulation 2 (LPA2). However, the original articles describing the role of LPA2 in PSII assembly have been retracted. To investigate the function of LPA2 in the model organism for green algae, Chlamydomonas reinhardtii, we generated knockout lpa2 mutants by using the CRISPR-Cas9 target-specific genome editing system. Biochemical analyses revealed the thylakoidal localization of LPA2 protein in the wild type (WT), whereas lpa2 mutants were characterized by a drastic reduction in the levels of D1, D2, CP47 and CP43 proteins. Consequently, reduced PSII supercomplex accumulation, chlorophyll content per cell, PSII quantum yield and photosynthetic oxygen evolution were measured in the lpa2 mutants, leading to the almost complete impairment of photoautotrophic growth. Pulse-chase experiments demonstrated that the absence of LPA2 protein caused reduced PSII assembly and reduced PSII turnover. Taken together, our data indicate that, in C. reinhardtii, LPA2 is required for PSII assembly and proper function.
Collapse
Affiliation(s)
- Michela Cecchin
- Dipartimento di BiotecnologieUniversità di VeronaStrada le Grazie 15Verona37134Italy
| | - Jooyeon Jeong
- Department of Life ScienceHanyang University222, Wangsimni‐ro, Seongdong‐guSeoul04763Korea
| | - Woojae Son
- Department of ChemistryHanyang University222, Wangsimni‐ro, Seongdong‐guSeoul04763Korea
| | - Minjae Kim
- Department of Life ScienceHanyang University222, Wangsimni‐ro, Seongdong‐guSeoul04763Korea
| | - Seunghye Park
- Department of Life ScienceHanyang University222, Wangsimni‐ro, Seongdong‐guSeoul04763Korea
| | - Luca Zuliani
- Dipartimento di BiotecnologieUniversità di VeronaStrada le Grazie 15Verona37134Italy
| | - Stefano Cazzaniga
- Dipartimento di BiotecnologieUniversità di VeronaStrada le Grazie 15Verona37134Italy
| | - Andrea Pompa
- Dipartimento di Scienze BiomolecolariUniversità degli studi di UrbinoVia Aurelio Saffi, 2Urbino61029Italy
- Istituto di Bioscienze e BiorisorseConsiglio Nazionale delle RicercheVia Madonna Alta, 130Perugia06128Italy
| | - Chan Young Kang
- Department of ChemistryHanyang University222, Wangsimni‐ro, Seongdong‐guSeoul04763Korea
| | - Sangsu Bae
- Department of ChemistryHanyang University222, Wangsimni‐ro, Seongdong‐guSeoul04763Korea
| | - Matteo Ballottari
- Dipartimento di BiotecnologieUniversità di VeronaStrada le Grazie 15Verona37134Italy
| | - EonSeon Jin
- Department of Life ScienceHanyang University222, Wangsimni‐ro, Seongdong‐guSeoul04763Korea
| |
Collapse
|
6
|
Nasuelli NA, De Marchi F, Cecchin M, De Paoli I, Onorato S, Pettinaroli R, Savoini G, Godi L. A case of acute demyelinating polyradiculoneuropathy with bilateral facial palsy after ChAdOx1 nCoV-19 vaccine. Neurol Sci 2021; 42:4747-4749. [PMID: 34272622 PMCID: PMC8285283 DOI: 10.1007/s10072-021-05467-w] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 07/04/2021] [Indexed: 11/28/2022]
Abstract
Background The coronavirus disease 2019 (COVID-19) global pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), began in late 2019. Researchers around the world are aggressively working to develop a vaccine. One of the vaccines approved against COVID-19 is Oxford–AstraZeneca chimpanzee adenovirus vectored vaccine ChAdOx1 nCoV-19. Case report We described a patient who developed four limb distal paraesthesia, postural instability, and facial diplegia, ten days after vaccination with ChAdOx1 nCoV-19 (ABW1277). The electrophysiological findings were compatible with acute demyelinating motor polyneuropathy (Guillain-Barrè syndrome). Discussion We therefore want to describe a temporal correlation between administration of ChAdOx1 nCoV-19 (ABW1277) vaccine and GBS without evidence of other predisposing infectious or autoimmune factors. This paper aims to highlight the importance of pharmacovigilance and subsequent reports will be needed to evaluate the possible correlation between these two events.
Collapse
Affiliation(s)
- Nicola Alessandro Nasuelli
- Department of Neurology, ASL NO, Borgomanero Hospital, Viale Zoppis 10, 28021, Borgomanero, Novara, Italy.
| | - Fabiola De Marchi
- Department of Neurology, ASL NO, Borgomanero Hospital, Viale Zoppis 10, 28021, Borgomanero, Novara, Italy.,Department of Neurology and ALS Centre, Traslational Medicine, University of Piemonte Orientale, Maggiore Della Carità Hospital, Novara, Italy
| | - Michela Cecchin
- Department of Neurology, ASL NO, Borgomanero Hospital, Viale Zoppis 10, 28021, Borgomanero, Novara, Italy
| | - Irene De Paoli
- Department of Neurology, ASL NO, Borgomanero Hospital, Viale Zoppis 10, 28021, Borgomanero, Novara, Italy
| | - Susanna Onorato
- Department of Neurology, ASL NO, Borgomanero Hospital, Viale Zoppis 10, 28021, Borgomanero, Novara, Italy
| | - Roberto Pettinaroli
- Department of Neurology, ASL NO, Borgomanero Hospital, Viale Zoppis 10, 28021, Borgomanero, Novara, Italy
| | - Giovanni Savoini
- Department of Neurology, ASL NO, Borgomanero Hospital, Viale Zoppis 10, 28021, Borgomanero, Novara, Italy
| | - Laura Godi
- Department of Neurology, ASL NO, Borgomanero Hospital, Viale Zoppis 10, 28021, Borgomanero, Novara, Italy
| |
Collapse
|
7
|
Cecchin M, Berteotti S, Paltrinieri S, Vigliante I, Iadarola B, Giovannone B, Maffei ME, Delledonne M, Ballottari M. Improved lipid productivity in Nannochloropsis gaditana in nitrogen-replete conditions by selection of pale green mutants. Biotechnol Biofuels 2020; 13:78. [PMID: 32336989 PMCID: PMC7175523 DOI: 10.1186/s13068-020-01718-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 04/15/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Nannochloropsis gaditana is a photosynthetic unicellular microalgae considered one of the most interesting marine algae to produce biofuels and food additive due to its rapid growth rate and high lipid accumulation. Although microalgae are attractive platforms for solar energy bioconversion, the overall efficiency of photosynthesis is reduced due to the steep light gradient in photobioreactors. Moreover, accumulation of lipids in microalgae for biofuels production is usually induced in a two-phase cultivation process by nutrient starvation, with additional time and costs associated. In this work, a biotechnological approach was directed for the isolation of strains with improved light penetration in photobioreactor combined with increased lipids productivity. RESULTS Mutants of Nannochloropsis gaditana were obtained by chemical mutagenesis and screened for having both a reduced chlorophyll content per cell and increased affinity for Nile red, a fluorescent dye which binds to cellular lipid fraction. Accordingly, one mutant, called e8, was selected and characterized for having a 30% reduction of chlorophyll content per cell and an almost 80% increase of lipid productivity compared to WT in nutrient-replete conditions, with C16:0 and C18:0 fatty acids being more than doubled in the mutant. Whole-genome sequencing revealed mutations in 234 genes in e8 mutant among which there is a non-conservative mutation in the dgd1 synthase gene. This gene encodes for an enzyme involved in the biosynthesis of DGDG, one of the major lipids found in the thylakoid membrane and it is thus involved in chloroplast biogenesis. Lipid biosynthesis is strongly influenced by light availability in several microalgae species, including Nannochloropsis gaditana: reduced chlorophyll content per cell and more homogenous irradiance in photobioreactor is at the base for the increased lipid productivity observed in the e8 mutant. CONCLUSIONS The results herein obtained presents a promising strategy to produce algal biomass enriched in lipid fraction to be used for biofuel and biodiesel production in a single cultivation process, without the additional complexity of the nutrient starvation phase. Genome sequencing and identification of the mutations introduced in e8 mutant suggest possible genes responsible for the observed phenotypes, identifying putative target for future complementation and biotechnological application.
Collapse
Affiliation(s)
- Michela Cecchin
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Silvia Berteotti
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Stefania Paltrinieri
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Ivano Vigliante
- Dipartimento di Scienze della Vita e Biologia dei Sistemi, Unità di Fisiologia Vegetale, Università di Torino, Via Quarello 15/a, 10135 Turin, Italy
| | - Barbara Iadarola
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Barbara Giovannone
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Massimo E. Maffei
- Dipartimento di Scienze della Vita e Biologia dei Sistemi, Unità di Fisiologia Vegetale, Università di Torino, Via Quarello 15/a, 10135 Turin, Italy
| | - Massimo Delledonne
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Matteo Ballottari
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134 Verona, Italy
| |
Collapse
|
8
|
Cecchin M, Marcolungo L, Rossato M, Girolomoni L, Cosentino E, Cuine S, Li‐Beisson Y, Delledonne M, Ballottari M. Chlorella vulgaris genome assembly and annotation reveals the molecular basis for metabolic acclimation to high light conditions. Plant J 2019; 100:1289-1305. [PMID: 31437318 PMCID: PMC6972661 DOI: 10.1111/tpj.14508] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/05/2019] [Accepted: 08/07/2019] [Indexed: 05/05/2023]
Abstract
Chlorella vulgaris is a fast-growing fresh-water microalga cultivated on the industrial scale for applications ranging from food to biofuel production. To advance our understanding of its biology and to establish genetics tools for biotechnological manipulation, we sequenced the nuclear and organelle genomes of Chlorella vulgaris 211/11P by combining next generation sequencing and optical mapping of isolated DNA molecules. This hybrid approach allowed us to assemble the nuclear genome in 14 pseudo-molecules with an N50 of 2.8 Mb and 98.9% of scaffolded genome. The integration of RNA-seq data obtained at two different irradiances of growth (high light, HL versus low light, LL) enabled us to identify 10 724 nuclear genes, coding for 11 082 transcripts. Moreover, 121 and 48 genes, respectively, were found in the chloroplast and mitochondrial genome. Functional annotation and expression analysis of nuclear, chloroplast and mitochondrial genome sequences revealed particular features of Chlorella vulgaris. Evidence of horizontal gene transfers from chloroplast to mitochondrial genome was observed. Furthermore, comparative transcriptomic analyses of LL versus HL provided insights into the molecular basis for metabolic rearrangement under HL versus LL conditions leading to enhanced de novo fatty acid biosynthesis and triacylglycerol accumulation. The occurrence of a cytosolic fatty acid biosynthetic pathway could be predicted and its upregulation upon HL exposure was observed, consistent with the increased lipid amount under HL conditions. These data provide a rich genetic resource for future genome editing studies, and potential targets for biotechnological manipulation of Chlorella vulgaris or other microalgae species to improve biomass and lipid productivity.
Collapse
Affiliation(s)
- Michela Cecchin
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Luca Marcolungo
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Marzia Rossato
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Laura Girolomoni
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Emanuela Cosentino
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Stephan Cuine
- Institute of Biosciences and Biotechnologies of Aix‐Marseille, UMR7265Aix‐Marseille UniversityCEACNRSCEA CadaracheSaint‐Paul‐lez DuranceF‐13108France
| | - Yonghua Li‐Beisson
- Institute of Biosciences and Biotechnologies of Aix‐Marseille, UMR7265Aix‐Marseille UniversityCEACNRSCEA CadaracheSaint‐Paul‐lez DuranceF‐13108France
| | - Massimo Delledonne
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Matteo Ballottari
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| |
Collapse
|
9
|
Uhmeyer A, Cecchin M, Ballottari M, Wobbe L. Impaired Mitochondrial Transcription Termination Disrupts the Stromal Redox Poise in Chlamydomonas. Plant Physiol 2017; 174:1399-1419. [PMID: 28500267 PMCID: PMC5490881 DOI: 10.1104/pp.16.00946] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 05/10/2017] [Indexed: 05/16/2023]
Abstract
In photosynthetic eukaryotes, the metabolite exchange between chloroplast and mitochondria ensures efficient photosynthesis under saturating light conditions. The Chlamydomonas reinhardtii mutant stm6 is devoid of the mitochondrial transcription termination factor MOC1 and aberrantly expresses the mitochondrial genome, resulting in enhanced photosynthetic hydrogen production and diminished light tolerance. We analyzed the modulation of mitochondrial and chlororespiration during the acclimation of stm6 and the MOC1-complemented strain to excess light. Although light stress stimulated mitochondrial respiration via the energy-conserving cytochrome c pathway in both strains, the mutant was unable to fine-tune the expression and activity of oxidative phosphorylation complex I in excess light, which was accompanied by an increased mitochondrial respiration via the alternative oxidase pathway. Furthermore, stm6 failed to fully activate chlororespiration and cyclic electron flow due to a more oxidized state of the chloroplast stroma, which is caused by an increased mitochondrial electron sink capacity. Increased susceptibility to photoinhibition of PSII in stm6 demonstrates that the MOC1-dependent modulation of mitochondrial respiration helps control the stromal redox poise as a crucial part of high-light acclimation in C. reinhardtii.
Collapse
Affiliation(s)
- Andreas Uhmeyer
- Bielefeld University, Faculty of Biology, Center for Biotechnology, 33615 Bielefeld, Germany
| | - Michela Cecchin
- Universita degli Studi di Verona, Department of Biotechnology, 37134 Verona, Italy
| | - Matteo Ballottari
- Universita degli Studi di Verona, Department of Biotechnology, 37134 Verona, Italy
| | - Lutz Wobbe
- Bielefeld University, Faculty of Biology, Center for Biotechnology, 33615 Bielefeld, Germany
| |
Collapse
|
10
|
Nasuelli N, Cecchin M, Onorato S, Savoini G, Marino S, Fantini F, Diana C, Godi L. 48. Cranial nerve involvement as a unusual presentation of multifocal motor neuropathy. Clin Neurophysiol 2016. [DOI: 10.1016/j.clinph.2016.10.060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
11
|
Cantello R, Varrasi C, Tarletti R, Cecchin M, D'Andrea F, Veggiotti P, Bellomo G, Monaco F. Ketogenic diet: electrophysiological effects on the normal human cortex. Epilepsia 2007; 48:1756-1763. [PMID: 17561954 DOI: 10.1111/j.1528-1167.2007.01156.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE To explore the cortical electrophysiology of the ketogenic diet (KD) in the normal human. KD is effective against refractory epilepsy, but its precise mechanism is obscure. At the transmitter level, an enhancement of GABA inhibition has often been proposed. METHODS We studied eight healthy volunteers undergoing a "classic" KD for 2 weeks. We measured several biochemical variables at baseline (T0), after 1 week (T1) and 2 weeks (T2) of KD, then 3 months after the KD conclusion (T3). Ketosis was quantified as 24-h ketonuria. At the same time, we studied the motor cortical excitability by means of transcranial magnetic stimulation (TMS). We also quantitatively evaluated the EEG signal in search of frequency shifts over the rolandic areas. RESULTS Significant (p < 0.05) neurophysiological changes appeared at T2. These consisted of a strengthening of short-latency cortical inhibition (SICI), a TMS index which is thought to reflect GABA-A inhibition in the cortex. Then, there was an enhancement of the beta EEG band over the perirolandic region, similar to that following administration of GABA-A agonists. All changes disappeared at T3. CONCLUSIONS A standard, short-term KD affected the cortical physiology of the normal human. The main changes were an augmented SICI and an increased perirolandic beta EEG activity, which are compatible with a lower level of neural excitation within the cortex.
Collapse
Affiliation(s)
- Roberto Cantello
- Department of Clinical and Experimental Medicine, Section of NeurologySection of Clinical Chemistry, "A. Avogadro" University, Novara, ItalyDepartment of Diet and Nutrition, "Maggiore della Carità" Hospital, Novara, ItalyDepartment of Child Neurology and Psychiatry, IRCCS Fondazione, Istituto Neurologico Casimiro Mondino, University of Pavia, Italy
| | - Claudia Varrasi
- Department of Clinical and Experimental Medicine, Section of NeurologySection of Clinical Chemistry, "A. Avogadro" University, Novara, ItalyDepartment of Diet and Nutrition, "Maggiore della Carità" Hospital, Novara, ItalyDepartment of Child Neurology and Psychiatry, IRCCS Fondazione, Istituto Neurologico Casimiro Mondino, University of Pavia, Italy
| | - Roberto Tarletti
- Department of Clinical and Experimental Medicine, Section of NeurologySection of Clinical Chemistry, "A. Avogadro" University, Novara, ItalyDepartment of Diet and Nutrition, "Maggiore della Carità" Hospital, Novara, ItalyDepartment of Child Neurology and Psychiatry, IRCCS Fondazione, Istituto Neurologico Casimiro Mondino, University of Pavia, Italy
| | - Michela Cecchin
- Department of Clinical and Experimental Medicine, Section of NeurologySection of Clinical Chemistry, "A. Avogadro" University, Novara, ItalyDepartment of Diet and Nutrition, "Maggiore della Carità" Hospital, Novara, ItalyDepartment of Child Neurology and Psychiatry, IRCCS Fondazione, Istituto Neurologico Casimiro Mondino, University of Pavia, Italy
| | - Federico D'Andrea
- Department of Clinical and Experimental Medicine, Section of NeurologySection of Clinical Chemistry, "A. Avogadro" University, Novara, ItalyDepartment of Diet and Nutrition, "Maggiore della Carità" Hospital, Novara, ItalyDepartment of Child Neurology and Psychiatry, IRCCS Fondazione, Istituto Neurologico Casimiro Mondino, University of Pavia, Italy
| | - Pierangelo Veggiotti
- Department of Clinical and Experimental Medicine, Section of NeurologySection of Clinical Chemistry, "A. Avogadro" University, Novara, ItalyDepartment of Diet and Nutrition, "Maggiore della Carità" Hospital, Novara, ItalyDepartment of Child Neurology and Psychiatry, IRCCS Fondazione, Istituto Neurologico Casimiro Mondino, University of Pavia, Italy
| | - Giorgio Bellomo
- Department of Clinical and Experimental Medicine, Section of NeurologySection of Clinical Chemistry, "A. Avogadro" University, Novara, ItalyDepartment of Diet and Nutrition, "Maggiore della Carità" Hospital, Novara, ItalyDepartment of Child Neurology and Psychiatry, IRCCS Fondazione, Istituto Neurologico Casimiro Mondino, University of Pavia, Italy
| | - Francesco Monaco
- Department of Clinical and Experimental Medicine, Section of NeurologySection of Clinical Chemistry, "A. Avogadro" University, Novara, ItalyDepartment of Diet and Nutrition, "Maggiore della Carità" Hospital, Novara, ItalyDepartment of Child Neurology and Psychiatry, IRCCS Fondazione, Istituto Neurologico Casimiro Mondino, University of Pavia, Italy
| |
Collapse
|
12
|
Civardi C, Collini A, Varrasi C, Bolamperti L, Tarletti R, Cecchin M, Cantello R. P37.24 Human motor cortical excitability in migraine without aura: A transcranial magnetic stimulation study. Clin Neurophysiol 2006. [DOI: 10.1016/j.clinph.2006.06.678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
13
|
Cantello R, Civardi C, Varrasi C, Vicentini R, Cecchin M, Boccagni C, Monaco F. Excitability of the human epileptic cortex after chronic valproate: A reappraisal. Brain Res 2006; 1099:160-6. [PMID: 16774745 DOI: 10.1016/j.brainres.2006.04.094] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2006] [Revised: 04/22/2006] [Accepted: 04/27/2006] [Indexed: 11/16/2022]
Abstract
We explored the action of chronic valproic acid (VPA) on the human epileptic cortex by means of transcranial magnetic stimulation (TMS). TMS is an emerging biomarker for neurotropic drugs. We had 15 drug-naive patients with different epileptic syndromes. Interictally, we measured several TMS indexes of cortical excitability before commencing VPA and 3 months later. At that time, all patients were clinical responders to the drug, whose plasma levels were in the "therapeutic range". We then compared the two conditions, while 18 healthy subjects, of whom 12 were retested at a similar delay, acted as controls. In the pooled patients, the baseline resting motor threshold to TMS was similar to that of controls, but it increased significantly (P < 0.05) after VPA. Intracortical facilitation, another index of cortical excitability, was abnormally enhanced at baseline but decreased significantly after VPA (P < 0.05). On splitting patients according to their diagnosis, the threshold increase was significant (P < 0.05) among partial, but not generalized epilepsies. The reverse was true for changes in intracortical facilitation. TMS phenomena had no linear relation to VPA serum levels. Based on the known pharmacology of TMS effects, VPA reduced the intrinsic membrane excitability of motor cortical neurons, possibly through changes in Na+ channel activity. Then, VPA corrected a transmitter-mediated interneuronal hyper-excitability of the primary motor cortex. The former effect was best seen in partial, and the latter in generalized epilepsy patients.
Collapse
Affiliation(s)
- Roberto Cantello
- Department of Clinical and Experimental Medicine, Section of Neurology, Università del Piemonte Orientale A. Avogadro, Novara, Italy.
| | | | | | | | | | | | | |
Collapse
|
14
|
Varrasi C, Civardi C, Boccagni C, Cecchin M, Vicentini R, Monaco F, Cantello R. Cortical excitability in drug-naive patients with partial epilepsy: A cross-sectional study. Neurology 2004; 63:2051-5. [PMID: 15596749 DOI: 10.1212/01.wnl.0000145770.95990.82] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To use paired-pulse transcranial magnetic stimulation (TMS) to investigate cortical excitability in drug-naive patients with partial epilepsy. METHODS Twenty-one drug-naive patients with partial epilepsy and 15 control subjects were studied. The relaxed threshold to TMS, the central silent period, and the intracortical inhibition/facilitation were measured. Statistics implied cluster analysis methods. Also assessed were the patient interictal EEG epileptiform abnormalities (EAs) on a semiquantitative basis. Then the TMS was contrasted to the clinical and EEG findings, using chi2 or Fisher exact tests. RESULTS One-third of the patients made up a "pathologic" cluster with a disrupted intracortical inhibition (p < 0.01). Two-thirds had a normal inhibition. Interictal EAs predominated in the pathologic cluster, for frequency (p < 0.04), duration (p < 0.04), and focality (p < 0.02). CONCLUSIONS Intracortical inhibition, which was impaired in one-third of the patients, reflects gamma-aminobutyric acid (GABA) activity within cortical area 4. Defective GABA inhibition is a typical pathogenic factor in partial epilepsy. Transcranial magnetic stimulation proved able to detect it. The weaker cortical inhibition had a direct relation to the severity of interictal epileptiform abnormalities.
Collapse
Affiliation(s)
- C Varrasi
- Department of Medical Sciences, Section of Neurology, Università del Piemonte Orientale A. Avogadro, Novara, Italy
| | | | | | | | | | | | | |
Collapse
|
15
|
Hofmeyer A, Cecchin M. Enactment of virtue ethics: collaboration between nurse academics and international students in questionnaire design. AUST J ADV NURS 2001; 18:8-13. [PMID: 11878508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Increased enrolment of international nursing students in undergraduate and postgraduate programs is predicted as Australian universities compete for students in the globalised university market. This study explored issues impacting on the ability of international nursing students to achieve their study goals at an Australian university (n=29). However, this paper principally describes the design of the instrument by two nursing lecturers and international nursing students (n=10) in a collaborative process, characterised by a pluralistic world view and the enactment of virtue ethics. The myth of the term 'ESL' is critiqued, and challenged. In designing the instrument, we argued it was essential to be cognisant of the conceptual attributes and embedded meanings of language for the unique study population, to ensure face and content validity.
Collapse
Affiliation(s)
- A Hofmeyer
- School of Nursing, Faculty of Health Sciences, Flinders University, Adelaide, South Australia
| | | |
Collapse
|
16
|
Abstract
This exploratory study conducted in 1996 described the profiles, roles and preparation of twelve South Australian registered nurses in relation to their provision of education programs for nurses from South East Asia. The research showed respondents were well qualified and highly experienced educators whose roles were complex. Their preparation for providing education programs for nurse from South East Asia had been haphazard and inadequate. Consequently respondents considered they were not fully prepared for the providing this specialised education. Career planning and a more strategic approach to the development of specific expertise are essential to support an international approach to nurse education. Nurse education that values intercultural awareness, and is multicultural and global would benefit both local and international students. Development of germane knowledge, skill, attitudes and behaviours is recommended to ensure excellence in the provision of international nurse education. An action research model is proposed as an alternative to traditional professional development to prepare providers of international education.
Collapse
Affiliation(s)
- M Cecchin
- International Programs School of Nursing, Flinders University of South Australia
| |
Collapse
|