I grew up in Corsica (France) and completed my PhD on Bacterial Symbioses in Nautiloids at the University Pierre and Marie Curie in Paris (2006). This was followed by a one-year Teaching and Researching position on “Phylogenetic and functional aspects of bacterial symbioses in Cephalopods” at the National Museum of Natural History in Paris (2007-2008).
In 2008, I was awarded with a three-year Marie Curie outgoing postdoctoral fellowship to study the influence of environmental stresses on cnidaria-dinoflagellate symbioses in Australia (University of Queensland, Brisbane). In January 2012, I started a postdoctoral contract funded by the Swiss National Science Foundation (EPFL, Lausanne Switzerland) to undertake collaborative research with the Climate Change Cluster (C3) combining my technical skills and knowledge on symbiosis with world leading expertise in coral photobiology and modelling.
Since January 2014, I am a Research fellow and deputy team leader within (C3), where I develop research on coral symbiosis, seagrass and genetic engineering of microalgae. The ultimate aim of this research is to develop and implement the next generation of Environmental Impact Assessment on marine ecosystems including coral reefs and seagrass.
Member of the International Symbiosis Society
Member of editorial board of Nature Scientific Reports, Frontiers in Microbial Symbioses (Frontiers Microbiology) and Frontiers in Coral research (Frontiers in Marine Science).
Reviewer of scientific papers for ISME Journal,Trends in Microbiology, Environmental Microbiology, Frontiers Microbiology, Molecular Ecology, Bioessays, Plos ONE, Journal of Experimental Biology, Autophagy, Marine Biology, Marine Environmental Research, Marine Biotechnology, Ecotoxicology.
Can supervise: YES
- Ecophysiology of symbioses
- Development of sublethal markers of stress for coral reef and seagrass monitoring
- Genetic engineering of microalgae
- Development of imaging techniques combined with isotopic labelling to study metabolic function
Coral reef Ecosystems:
Coordinator of coral bleaching project on the Marine Productivity and Climate Change (42h, UTS Subject Number 91156).
Programme director for the Advanced Degree in Environmental Biotechnology and Lecturer for Biotechnology (2h, UTS Subject Number 91142).
Other teaching areas include: Seagrass, Symbiotic interactions, Environmental Impact Assessment, Molecular Biology, Physiology.
Kim, M, Pernice, M, Watson-Lazowski, A, Guagliardo, P, Kilburn, MR, Larkum, AWD, Raven, JA & Ralph, PJ 2019, 'Effect of reduced irradiance on 13C uptake, gene expression and protein activity of the seagrass Zostera muelleri.', Marine environmental research, vol. 149, pp. 80-89.View/Download from: UTS OPUS or Publisher's site
Photosynthesis in the seagrass Zostera muelleri remains poorly understood. We investigated the effect of reduced irradiance on the incorporation of 13C, gene expression of photosynthetic, photorespiratory and intermediates recycling genes as well as the enzymatic content and activity of Rubisco and PEPC within Z. muelleri. Following 48 h of reduced irradiance, we found that i) there was a ∼7 fold reduction in 13C incorporation in above ground tissue, ii) a significant down regulation of photosynthetic, photorespiratory and intermediates recycling genes and iii) no significant difference in enzyme activity and content. We propose that Z. muelleri is able to alter its physiology in order to reduce the amount of C lost through photorespiration to compensate for the reduced carbon assimilation as a result of reduced irradiance. In addition, the first estimated rate constant (Kcat) and maximum rates of carboxylation (Vcmax) of Rubisco is reported for the first time for Z. muelleri.
Buapet, P, Mohammadi, NS, Pernice, M, Kumar, M, Kuzhiumparambil, U & Ralph, PJ 2019, 'Excess copper promotes photoinhibition and modulates the expression of antioxidant-related genes in Zostera muelleri', AQUATIC TOXICOLOGY, vol. 207, pp. 91-100.View/Download from: UTS OPUS or Publisher's site
Commault, AS, Fabris, M, Kuzhiumparambil, U, Adriaans, J, Pernice, M & Ralph, PJ 2019, 'Methyl jasmonate treatment affects the regulation of the 2-C-methyl-D-erythritol 4-phosphate pathway and early steps of the triterpenoid biosynthesis in Chlamydomonas reinhardtii', Algal Research, vol. 39.View/Download from: UTS OPUS or Publisher's site
© 2019 Elsevier B.V. Terpenoids are a large and diverse class of naturally occurring metabolites serving many industrial applications and natural roles. Economically important terpenoids are often produced in low abundance from their natural sources, making their industrial-scale production challenging or uneconomical, therefore engineered microorganisms are frequently used as heterologous production platforms. Photosynthetic microorganisms, such as the green alga Chlamydomonas reinhardtii, represent promising systems to produce terpenoids in a cost-effective and sustainable manner, but knowledge about the regulation of their terpenoid metabolism remains limited. Here we report on the investigation of the phytohormone methyl jasmonate (MeJA) as elicitor of algal terpenoid synthesis. We treated C. reinhardtii cells in mid-exponential growth phase with three different concentrations of MeJA (0.05, 0.5 and 1 mM). The highest concentration of MeJA affected the photosynthetic activity of the cells, arrested the growth and up-regulated key genes of the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway, leading to a significant increase in intermediates of this pathway, squalene and (S)-2,3-epoxysqualene, while the abundance of cycloartenol, and two main sterols (ergosterol and 7-dehydroporiferasterol) decreased. These data suggest the redirection of the carbon flux towards the synthesis of yet uncharacterised triterpenoid secondary metabolites upon MeJA treatment. Our results offer important new insights into the regulation of the triterpenoid metabolism in C. reinhardtii and raise important questions on hormonal signalling in microalgae. Phytohormone treatment is tested for the first time in algae, where it holds great potential for identifying key transcriptional regulators of the MEP pathway as targets for future metabolic engineering studies for improve production of high-value triterpenoids.
Achlatis, M, Pernice, M, Green, K, de Goeij, JM, Guagliardo, P, Kilburn, MR, Hoegh-Guldberg, O & Dove, S 2019, 'Single-cell visualization indicates direct role of sponge host in uptake of dissolved organic matter.', Proceedings. Biological sciences, vol. 286, no. 1916.View/Download from: UTS OPUS or Publisher's site
Marine sponges are set to become more abundant in many near-future oligotrophic environments, where they play crucial roles in nutrient cycling. Of high importance is their mass turnover of dissolved organic matter (DOM), a heterogeneous mixture that constitutes the largest fraction of organic matter in the ocean and is recycled primarily by bacterial mediation. Little is known, however, about the mechanism that enables sponges to incorporate large quantities of DOM in their nutrition, unlike most other invertebrates. Here, we examine the cellular capacity for direct processing of DOM, and the fate of the processed matter, inside a dinoflagellate-hosting bioeroding sponge that is prominent on Indo-Pacific coral reefs. Integrating transmission electron microscopy with nanoscale secondary ion mass spectrometry, we track 15N- and 13C-enriched DOM over time at the individual cell level of an intact sponge holobiont. We show initial high enrichment in the filter-feeding cells of the sponge, providing visual evidence of their capacity to process DOM through pinocytosis without mediation of resident bacteria. Subsequent enrichment of the endosymbiotic dinoflagellates also suggests sharing of host nitrogenous wastes. Our results shed light on the physiological mechanism behind the ecologically important ability of sponges to cycle DOM via the recently described sponge loop.
Goh, CJ, Park, D, Lee, JS, Davey, PA, Pernice, M, Ralph, PJ & Hahn, Y 2019, 'Zostera virus T - a novel virus of the genus Tepovirus identified in the eelgrass, Zostera muelleri', ACTA VIROLOGICA, vol. 63, no. 4, pp. 366-+.View/Download from: Publisher's site
Meunier, V, Bonnet, S, Pernice, M, Benavides, M, Lorrain, A, Grosso, O, Lambert, C & Houlbreque, F 2019, 'Bleaching forces coral's heterotrophy on diazotrophs and Synechococcus', ISME JOURNAL, vol. 13, no. 11, pp. 2882-2886.View/Download from: UTS OPUS or Publisher's site
Pernice, M, Raina, JB, Rädecker, N, Cárdenas, A, Pogoreutz, C & Voolstra, CR 2019, 'Down to the bone: the role of overlooked endolithic microbiomes in reef coral health', ISME Journal.View/Download from: UTS OPUS or Publisher's site
© 2019, The Author(s). Reef-building corals harbour an astonishing diversity of microorganisms, including endosymbiotic microalgae, bacteria, archaea, and fungi. The metabolic interactions within this symbiotic consortium are fundamental to the ecological success of corals and the unique productivity of coral reef ecosystems. Over the last two decades, scientific efforts have been primarily channelled into dissecting the symbioses occurring in coral tissues. Although easily accessible, this compartment is only 2–3 mm thick, whereas the underlying calcium carbonate skeleton occupies the vast internal volume of corals. Far from being devoid of life, the skeleton harbours a wide array of algae, endolithic fungi, heterotrophic bacteria, and other boring eukaryotes, often forming distinct bands visible to the bare eye. Some of the critical functions of these endolithic microorganisms in coral health, such as nutrient cycling and metabolite transfer, which could enable the survival of corals during thermal stress, have long been demonstrated. In addition, some of these microorganisms can dissolve calcium carbonate, weakening the coral skeleton and therefore may play a major role in reef erosion. Yet, experimental data are wanting due to methodological limitations. Recent technological and conceptual advances now allow us to tease apart the complex physical, ecological, and chemical interactions at the heart of coral endolithic microbial communities. These new capabilities have resulted in an excellent body of research and provide an exciting outlook to further address the functional microbial ecology of the “overlooked” coral skeleton.
Ramarajan, M, Fabris, M, Abbriano, RM, Pernice, M & Ralph, PJ 2019, 'Novel endogenous promoters for genetic engineering of the marine microalga Nannochloropsis gaditana CCMP526', Algal Research, vol. 44.View/Download from: UTS OPUS or Publisher's site
© 2019 Elsevier B.V. Nannochloropsis is a marine microalga from the Eustigmatophyceae stramenopile lineage that has been studied extensively due to a broad range of industrial applications, mostly related to their oil and pigment production. However, tools to genetically engineer members of this group, and therefore further understand and maximise their industrial potential are still limited. In order to expand the potential industrial uses of this organism, several molecular tools, including gene promoters of different strength, are needed. A comprehensive and diverse set of well-characterized promoters is key to a number of genetic engineering and synthetic biology applications, such as the assembly of complex biological functions or entire metabolic pathways. In this study, we measured the promoter activity of three endogenous constitutive promoters from N. gaditana genes EPPSII (Nga02101); HSP90 (Nga00934); ATPase (Nga06354.1) in driving the expression of a Sh ble- mVenus fluorescent reporter fusion protein. Through a combined approach that includes flow cytometry, RT-qPCR and immunoblotting, we profiled the activity of these promoters at both the transcript and protein level. Two promoters HSP90 (Nga00934) and EPPSII (Nga02101) outperformed the widely used β-tubulin promoter, exhibiting 4.5 and 3.1-fold higher mVenus fluorescence, respectively. A third promoter ATPase (Nga06354.1) was also able to drive the expression of transgenes, albeit at lower levels. We show that the new promoters identified in this study are valuable tools, which can be used for genetic engineering and functional genetics studies in N. gaditana.
Shah Mohammadi, N, Buapet, P, Pernice, M, Signal, B, Kahlke, T, Hardke, L & Ralph, PJ 2019, 'Transcriptome profiling analysis of the seagrass, Zostera muelleri under copper stress.', Marine pollution bulletin, vol. 149.View/Download from: UTS OPUS or Publisher's site
Copper (Cu) in an essential trace metal but it can also contaminate coastal waters at high concentrations mainly from agricultural run-off and mining activities which are detrimental to marine organisms including seagrasses. The molecular mechanisms driving Cu toxicity in seagrasses are not clearly understood yet. Here, we investigated the molecular responses of the Australian seagrass, Z. muelleri at the whole transcriptomic level after 7 days of exposure to 250 μg Cu L-1 and 500 μg Cu L-1. The leaf-specific whole transcriptome results showed a concentration-dependent disturbance in chloroplast function, regulatory stress responses and defense mechanisms. This study provided new insights into the responses of seagrasses to trace metal stress and reports possible candidate genes which can be considered as biomarkers to improve conservation and management of seagrass meadows.
Espinoza-Vergara, G, Noorian, P, Silva-Valenzuela, CA, Raymond, BBA, Allen, C, Hoque, MM, Sun, S, Johnson, MS, Pernice, M, Kjelleberg, S, Djordjevic, SP, Labbate, M, Camilli, A & McDougald, D 2019, 'Vibrio cholerae residing in food vacuoles expelled by protozoa are more infectious in vivo', Nature Microbiology.View/Download from: UTS OPUS or Publisher's site
Kim, M, Brodersen, KE, Szabó, M, Larkum, AWD, Raven, JA, Ralph, PJ & Pernice, M 2018, 'Low oxygen affects photophysiology and the level of expression of two-carbon metabolism genes in the seagrass Zostera muelleri.', Photosynthesis Research, vol. 136, no. 2, pp. 147-160.View/Download from: UTS OPUS or Publisher's site
Seagrasses are a diverse group of angiosperms that evolved to live in shallow coastal waters, an environment regularly subjected to changes in oxygen, carbon dioxide and irradiance. Zostera muelleri is the dominant species in south-eastern Australia, and is critical for healthy coastal ecosystems. Despite its ecological importance, little is known about the pathways of carbon fixation in Z. muelleri and their regulation in response to environmental changes. In this study, the response of Z. muelleri exposed to control and very low oxygen conditions was investigated by using (i) oxygen microsensors combined with a custom-made flow chamber to measure changes in photosynthesis and respiration, and (ii) reverse transcription quantitative real-time PCR to measure changes in expression levels of key genes involved in C4 metabolism. We found that very low levels of oxygen (i) altered the photophysiology of Z. muelleri, a characteristic of C3 mechanism of carbon assimilation, and (ii) decreased the expression levels of phosphoenolpyruvate carboxylase and carbonic anhydrase. These molecular-physiological results suggest that regulation of the photophysiology of Z. muelleri might involve a close integration between the C3 and C4, or other CO2 concentrating mechanisms metabolic pathways. Overall, this study highlights that the photophysiological response of Z. muelleri to changing oxygen in water is capable of rapid acclimation and the dynamic modulation of pathways should be considered when assessing seagrass primary production.
Sablok, G, Hayward, RJ, Davey, PA, Santos, RP, Schliep, M, Larkum, A, Pernice, M, Dolferus, R & Ralph, PJ 2018, 'SeagrassDB: An open-source transcriptomics landscape for phylogenetically profiled seagrasses and aquatic plants', SCIENTIFIC REPORTS, vol. 8.View/Download from: UTS OPUS or Publisher's site
Davey, PA, Pernice, M, Ashworth, J, Kuzhiumparambil, U, Szabó, M, Dolferus, R & Ralph, PJ 2018, 'A new mechanistic understanding of light-limitation in the seagrass Zostera muelleri.', Marine Environmental Research, vol. 134, pp. 55-67.View/Download from: UTS OPUS or Publisher's site
In this study we investigated the effect of light-limitation (∼20 μmol photons m-2 s-1) on the southern hemisphere seagrass, Zostera muelleri. RNA sequencing, chlorophyll fluorometry and HPLC techniques were used to investigate how the leaf-specific transcriptome drives changes in photosynthesis and photo-pigments in Z. muelleri over 6 days. 1593 (7.51%) genes were differentially expressed on day 2 and 1481 (6.98%) genes were differentially expressed on day 6 of the experiment. Differential gene expression correlated with significant decreases in rETRMax, Ik, an increase in Yi (initial photosynthetic quantum yield of photosystem II), and significant changes in pigment composition. Regulation of carbohydrate metabolism was observed along with evidence that abscisic acid may serve a role in the low-light response of this seagrass. This study provides a novel understanding of how Z. muelleri responds to light-limitation in the marine water column and provides potential molecular markers for future conservation monitoring efforts.
Achlatis, M, Pernice, M, Green, K, Guagliardo, P, Kilburn, MR, Hoegh-Guldberg, O & Dove, S 2018, 'Single-cell measurement of ammonium and bicarbonate uptake within a photosymbiotic bioeroding sponge.', The ISME journal, vol. 12, no. 5, pp. 1308-1318.View/Download from: UTS OPUS or Publisher's site
Some of the most aggressive coral-excavating sponges host intracellular dinoflagellates from the genus Symbiodinium, which are hypothesized to provide the sponges with autotrophic energy that powers bioerosion. Investigations of the contribution of Symbiodinium to host metabolism and particularly inorganic nutrient recycling are complicated, however, by the presence of alternative prokaryotic candidates for this role. Here, novel methods are used to study nutrient assimilation and transfer within and between the outer-layer cells of the Indopacific bioeroding sponge Cliona orientalis. Combining stable isotope labelling, transmission electron microscopy (TEM) and nanoscale secondary ion mass spectrometry (NanoSIMS), we visualize and measure metabolic activity at the individual cell level, tracking the fate of 15N-ammonium and 13C-bicarbonate within the intact holobiont. We found strong uptake of both inorganic sources (especially 13C-bicarbonate) by Symbiodinium cells. Labelled organic nutrients were translocated from Symbiodinium to the Symbiodinium-hosting sponge cells within 6 h, and occasionally to other sponge cells within 3 days. By contrast, prokaryotic symbionts were not observed to participate in inorganic nutrient assimilation in the outer layers of the sponge. Our findings strongly support the metabolic interaction between the sponge and dinoflagellates, shedding light on the ecological advantages and adaptive capacity of photosymbiotic bioeroding sponges in oligotrophic marine habitats.
Rädecker, N, Raina, J-B, Pernice, M, Perna, G, Guagliardo, P, Kilburn, MR, Aranda, M & Voolstra, CR 2018, 'Corrigendum: Using Aiptasia as a Model to Study Metabolic Interactions in Cnidarian-Symbiodinium Symbioses.', Frontiers in physiology, vol. 9.View/Download from: UTS OPUS or Publisher's site
[This corrects the article on p. 214 in vol. 9, PMID: 29615919.].
Raedecker, N, Raina, J-B, Pernice, M, Perna, G, Guagliardo, P, Kilburn, MR, Aranda, M & Voolstra, CR 2018, 'Using Aiptasia as a Model to Study Metabolic Interactions in Cnidarian-Symbiodinium Symbioses', FRONTIERS IN PHYSIOLOGY, vol. 9.View/Download from: UTS OPUS or Publisher's site
Brodersen, KE, Siboni, N, Nielsen, DA, Pernice, M, Ralph, PJ, Seymour, J & Kühl, M 2018, 'Seagrass rhizosphere microenvironment alters plant-associated microbial community composition.', Environmental microbiology, vol. 20, no. 8, pp. 2854-2864.View/Download from: UTS OPUS or Publisher's site
The seagrass rhizosphere harbors dynamic microenvironments, where plant-driven gradients of O2 and dissolved organic carbon form microhabitats that select for distinct microbial communities. To examine how seagrass-mediated alterations of rhizosphere geochemistry affect microbial communities at the microscale level, we applied 16S rRNA amplicon sequencing of artificial sediments surrounding the meristematic tissues of the seagrass Zostera muelleri together with microsensor measurements of the chemical conditions at the basal leaf meristem (BLM). Radial O2 loss (ROL) from the BLM led to ∼ 300 µm thick oxic microzones, wherein pronounced decreases in H2 S and pH occurred. Significantly higher relative abundances of sulphate-reducing bacteria were observed around the meristematic tissues compared to the bulk sediment, especially around the root apical meristems (RAM; ∼ 57% of sequences). Within oxic microniches, elevated abundances of sulphide-oxidizing bacteria were observed compared to the bulk sediment and around the RAM. However, sulphide oxidisers within the oxic microzone did not enhance sediment detoxification, as rates of H2 S re-oxidation here were similar to those observed in a pre-sterilized root/rhizome environment. Our results provide novel insights into how chemical and microbiological processes in the seagrass rhizosphere modulate plant-microbe interactions potentially affecting seagrass health.
Giardina, M, Cheong, S, Marjo, CE, Clode, PL, Guagliardo, P, Pickford, R, Pernice, M, Seymour, JR & Raina, J-B 2018, 'Quantifying Inorganic Nitrogen Assimilation by Synechococcus Using Bulk and Single-Cell Mass Spectrometry: A Comparative Study.', Frontiers in microbiology, vol. 9.View/Download from: UTS OPUS or Publisher's site
Microorganisms drive most of the major biogeochemical cycles in the ocean, but the rates at which individual species assimilate and transform key elements is generally poorly quantified. One of these important elements is nitrogen, with its availability limiting primary production across a large proportion of the ocean. Nitrogen uptake by marine microbes is typically quantified using bulk-scale approaches, such as Elemental Analyzer-Isotope Ratio Mass Spectrometry (EA-IRMS), which averages uptake over entire communities, masking microbial heterogeneity. However, more recent techniques, such as secondary ion mass spectrometry (SIMS), allow for elucidation of assimilation rates at the scale at which they occur: the single-cell level. Here, we combine and compare the application of bulk (EA-IRMS) and single-cell approaches (NanoSIMS and Time-of-Flight-SIMS) for quantifying the assimilation of inorganic nitrogen by the ubiquitous marine primary producer Synechococcus. We aimed to contrast the advantages and disadvantages of these techniques and showcase their complementarity. Our results show that the average assimilation of 15N by Synechococcus differed based on the technique used: values derived from EA-IRMS were consistently higher than those derived from SIMS, likely due to a combination of previously reported systematic depletion as well as differences in sample preparation. However, single-cell approaches offered additional layers of information, whereby NanoSIMS allowed for the quantification of the metabolic heterogeneity among individual cells and ToF-SIMS enabled identification of nitrogen assimilation into peptides. We suggest that this coupling of stable isotope-based approaches has great potential to elucidate the metabolic capacity and heterogeneity of microbial cells in natural environments.
Raina, J-B, Clode, PL, Cheong, S, Bougoure, J, Kilburn, MR, Reeder, A, Forêt, S, Stat, M, Beltran, V, Thomas-Hall, P, Tapiolas, D, Motti, CM, Gong, B, Pernice, M, Marjo, CE, Seymour, JR, Willis, BL & Bourne, DG 2017, 'Subcellular tracking reveals the location of dimethylsulfoniopropionate in microalgae and visualises its uptake by marine bacteria.', eLife, vol. 6, pp. 1-17.View/Download from: UTS OPUS or Publisher's site
Phytoplankton-bacteria interactions drive the surface ocean sulfur cycle and local climatic processes through the production and exchange of a key compound: dimethylsulfoniopropionate (DMSP). Despite their large-scale implications, these interactions remain unquantified at the cellular-scale. Here we use secondary-ion mass spectrometry to provide the first visualization of DMSP at sub-cellular levels, tracking the fate of a stable sulfur isotope ((34)S) from its incorporation by microalgae as inorganic sulfate to its biosynthesis and exudation as DMSP, and finally its uptake and degradation by bacteria. Our results identify for the first time the storage locations of DMSP in microalgae, with high enrichments present in vacuoles, cytoplasm and chloroplasts. In addition, we quantify DMSP incorporation at the single-cell level, with DMSP-degrading bacteria containing seven times more (34)S than the control strain. This study provides an unprecedented methodology to label, retain, and image small diffusible molecules, which can be transposable to other symbiotic systems.
Wangpraseurt, D, Holm, JB, Larkum, AWD, Pernice, M, Ralph, PJ, Suggett, DJ & Kühl, M 2017, 'In vivo Microscale Measurements of Light and Photosynthesis during Coral Bleaching: Evidence for the Optical Feedback Loop?', Frontiers in Microbiology, vol. 8, pp. 1-12.View/Download from: UTS OPUS or Publisher's site
Climate change-related coral bleaching, i.e., the visible loss of zooxanthellae from the coral host, is increasing in frequency and extent and presents a major threat to coral reefs globally. Coral bleaching has been proposed to involve accelerating light stress of their microalgal endosymbionts via a positive feedback loop of photodamage, symbiont expulsion and excess in vivo light exposure. To test this hypothesis, we used light and O2 microsensors to characterize in vivo light exposure and photosynthesis of Symbiodinium during a thermal stress experiment. We created tissue areas with different densities of Symbiodinium cells in order to understand the optical properties and light microenvironment of corals during bleaching. Our results showed that in bleached Pocillopora damicornis corals, Symbiodinium light exposure was up to fivefold enhanced relative to healthy corals, and the relationship between symbiont loss and light enhancement was well-described by a power-law function. Cell-specific rates of Symbiodinium gross photosynthesis and light respiration were enhanced in bleached P. damicornis compared to healthy corals, while areal rates of net photosynthesis decreased. Symbiodinium light exposure in Favites sp. revealed the presence of low light microniches in bleached coral tissues, suggesting that light scattering in thick coral tissues can enable photoprotection of cryptic symbionts. Our study provides evidence for the acceleration of in vivo light exposure during coral bleaching but this optical feedback mechanism differs between coral hosts. Enhanced photosynthesis in relation to accelerating light exposure shows that coral microscale optics exerts a key role on coral photophysiology and the subsequent degree of radiative stress during coral bleaching.
Goyen, S, Pernice, M, Szabó, M, Warner, ME, Ralph, PJ & Suggett, DJ 2017, 'A molecular physiology basis for functional diversity of hydrogen peroxide production amongst Symbiodinium spp. (Dinophyceae)', Marine Biology: international journal on life in oceans and coastal waters, vol. 164, no. 3.View/Download from: UTS OPUS or Publisher's site
Jiang, Z, Kumar, M, Padula, MP, Pernice, M, Kahlke, T, Kim, M & Ralph, PJ 2017, 'Development of an Efficient Protein Extraction Method Compatible with LC-MS/MS for Proteome Mapping in Two Australian Seagrasses Zostera muelleri and Posidonia australis.', Frontiers in Plant Science, vol. 8, pp. 1-14.View/Download from: UTS OPUS or Publisher's site
The availability of the first complete genome sequence of the marine flowering plant Zostera marina (commonly known as seagrass) in early 2016, is expected to significantly raise the impact of seagrass proteomics. Seagrasses are marine ecosystem engineers that are currently declining worldwide at an alarming rate due to both natural and anthropogenic disturbances. Seagrasses (especially species of the genus Zostera) are compromised for proteomic studies primarily due to the lack of efficient protein extraction methods because of their recalcitrant cell wall which is rich in complex polysaccharides and a high abundance of secondary metabolites in their cells. In the present study, three protein extraction methods that are commonly used in plant proteomics i.e., phenol (P); trichloroacetic acid/acetone/SDS/phenol (TASP); and borax/polyvinyl-polypyrrolidone/phenol (BPP) extraction, were evaluated quantitatively and qualitatively based on two dimensional isoelectric focusing (2D-IEF) maps and LC-MS/MS analysis using the two most abundant Australian seagrass species, namely Zostera muelleri and Posidonia australis. All three tested methods produced high quality protein extracts with excellent 2D-IEF maps in P. australis. However, the BPP method produces better results in Z. muelleri compared to TASP and P. Therefore, we further modified the BPP method (M-BPP) by homogenizing the tissue in a modified protein extraction buffer containing both ionic and non-ionic detergents (0.5% SDS; 1.5% Triton X-100), 2% PVPP and protease inhibitors. Further, the extracted proteins were solubilized in 0.5% of zwitterionic detergent (C7BzO) instead of 4% CHAPS. This slight modification to the BPP method resulted in a higher protein yield, and good quality 2-DE maps with a higher number of protein spots in both the tested seagrasses. Further, the M-BPP method was successfully utilized in western-blot analysis of phosphoenolpyruvate carboxylase (PEPC-a key enzyme for carbon metabolism). ...
Kumar, M, Padula, MP, Davey, P, Pernice, M, Jiang, Z, Sablok, G, Contreras-Porcia, L & Ralph, PJ 2017, 'Proteome Analysis Reveals Extensive Light Stress-Response Reprogramming in the Seagrass Zostera muelleri (Alismatales, Zosteraceae) Metabolism.', Frontiers in Plant Science, vol. 7, pp. 1-19.View/Download from: UTS OPUS or Publisher's site
Seagrasses are marine ecosystem engineers that are currently declining in abundance at an alarming rate due to both natural and anthropogenic disturbances in ecological niches. Despite reports on the morphological and physiological adaptations of seagrasses to extreme environments, little is known of the molecular mechanisms underlying photo-acclimation, and/or tolerance in these marine plants. This study applies the two-dimensional isoelectric focusing (2D-IEF) proteomics approach to identify photo-acclimation/tolerance proteins in the marine seagrass Zostera muelleri. For this, Z. muelleri was exposed for 10 days in laboratory mesocosms to saturating (control, 200 μmol photons m-2 s-1), super-saturating (SSL, 600 μmol photons m-2 s-1), and limited light (LL, 20 μmol photons m-2 s-1) irradiance conditions. Using LC-MS/MS analysis, 93 and 40 protein spots were differentially regulated under SSL and LL conditions, respectively, when compared to the control. In contrast to the LL condition, Z. muelleri robustly tolerated super-saturation light than control conditions, evidenced by their higher relative maximum electron transport rate and minimum saturating irradiance values. Proteomic analyses revealed up-regulation and/or appearances of proteins belonging to the Calvin-Benson and Krebs cycle, glycolysis, the glycine cleavage system of photorespiration, and the antioxidant system. These proteins, together with those from the inter-connected glutamate-proline-GABA pathway, shaped Z. muelleri photosynthesis and growth under SSL conditions. In contrast, the LL condition negatively impacted the metabolic activities of Z. muelleri by down-regulating key metabolic enzymes for photosynthesis and the metabolism of carbohydrates and amino acids, which is consistent with the observation with lower photosynthetic performance under LL condition. This study provides novel insights into the underlying molecular photo-acclimation mechanisms in Z. muelleri, in addition to identify...
Wangpraseurt, D, Pernice, M, Guagliardo, P, Kilburn, MR, Clode, PL, Polerecky, L & Kuehl, M 2016, 'Light microenvironment and single-cell gradients of carbon fixation in tissues of symbiont-bearing corals', ISME JOURNAL, vol. 10, no. 3, pp. 788-792.View/Download from: UTS OPUS or Publisher's site
Davey, PA, Pernice, M, Sablok, G, Larkum, A, Lee, HT, Golicz, A, Edwards, D, Dolferus, R & Ralph, P 2016, 'The emergence of molecular profiling and omics techniques in seagrass biology; furthering our understanding of seagrasses.', Functional & Integrative Genomics, vol. 16, no. 5, pp. 465-480.View/Download from: UTS OPUS or Publisher's site
Seagrass meadows are disappearing at alarming rates as a result of increasing coastal development and climate change. The emergence of omics and molecular profiling techniques in seagrass research is timely, providing a new opportunity to address such global issues. Whilst these applications have transformed terrestrial plant research, they have only emerged in seagrass research within the past decade; In this time frame we have observed a significant increase in the number of publications in this nascent field, and as of this year the first genome of a seagrass species has been sequenced. In this review, we focus on the development of omics and molecular profiling and the utilization of molecular markers in the field of seagrass biology. We highlight the advances, merits and pitfalls associated with such technology, and importantly we identify and address the knowledge gaps, which to this day prevent us from understanding seagrasses in a holistic manner. By utilizing the powers of omics and molecular profiling technologies in integrated strategies, we will gain a better understanding of how these unique plants function at the molecular level and how they respond to on-going disturbance and climate change events.
Kumar, M, Kuzhiumparambil, U, Pernice, M, Jiang, Z & Ralph, PJ 2016, 'Metabolomics: an emerging frontier of systems biology in marine macrophytes', ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS, vol. 16, pp. 76-92.View/Download from: UTS OPUS or Publisher's site
Pernice, M, Sinutok, S, Sablok, G, Commault, A, Schliep, M, Macreadie, P, Rasheed, M & Ralph, P 2016, 'Molecular physiology reveals ammonium uptake and related gene expression in the seagrass Zostera muelleri', Marine Environmental Research.View/Download from: UTS OPUS or Publisher's site
Ros, M, Pernice, M, Le Guillou, S, Doblin, MA, Schrameyer, V & Laczka, O 2016, 'Colorimetric detection of caspase 3 activity and reactive oxygen derivatives: Potential early indicators of thermal stress in corals', Journal of Marine Biology, vol. 2016, pp. 1-11.View/Download from: UTS OPUS or Publisher's site
© 2016 Mickael Ros et al. There is an urgent need to develop and implement rapid assessments of coral health to allow effective adaptive management in response to coastal development and global change. There is now increasing evidence that activation of caspase-dependent apoptosis plays a key role during coral bleaching and subsequent mortality. In this study, a "clinical" approach was used to assess coral health by measuring the activity of caspase 3 using a commercial kit. This method was first applied while inducing thermal bleaching in two coral species, Acropora millepora and Pocillopora damicornis. The latter species was then chosen to undergo further studies combining the detection of oxidative stress-related compounds (catalase activity and glutathione concentrations) as well as caspase activity during both stress and recovery phases. Zooxanthellae photosystem II (PSII) efficiency and cell density were measured in parallel to assess symbiont health. Our results demonstrate that the increased caspase 3 activity in the coral host could be detected before observing any significant decrease in the photochemical efficiency of PSII in the algal symbionts and/or their expulsion from the host. This study highlights the potential of host caspase 3 and reactive oxygen species scavenging activities as early indicators of stress in individual coral colonies.
Pernice, M, Dunn, SR, Tonk, L, Dove, SG, Domart-Coulon, I, Hoppe, P, Schintlmeister, A, Wagner, M & Meibom, A 2015, 'A nanoscale secondary ion mass spectrometry study of dinoagellate functional diversity in reef-building corals', Environmental Microbiology, vol. 17, no. 10, pp. 3570-3580.View/Download from: UTS OPUS or Publisher's site
Nutritional interactions between corals and symbiotic dinoflagellate algae lie at the heart of the structural foundation of coral reefs. Whilst the genetic diversity of Symbiodinium has attracted particular interest because of its contribution to the sensitivity of corals to environmental changes and bleaching (i.e. disruption of coraldinoflagellate symbiosis), very little is known about the in hospite metabolic capabilities of different Symbiodinium types. Using a combination of stable isotopic labelling and nanoscale secondary ion mass spectrometry (NanoSIMS), we investigated the ability of the intact symbiosis between the reef-building coral Isopora palifera, and Symbiodinium C or D types, to assimilate dissolved inorganic carbon (via photosynthesis) and nitrogen (as ammonium). Our results indicate that Symbiodinium types from two clades naturally associated with I.?palifera possess different metabolic capabilities. The Symbiodinium C type fixed and passed significantly more carbon and nitrogen to its coral host than the D type. This study provides further insights into the metabolic plasticity among different Symbiodinium types in hospite and strengthens the evidence that the more temperature-tolerant Symbiodinium D type may be less metabolically beneficial for its coral host under non-stressful conditions.
Pulpitel, T, Pernice, M, Simpson, SJ & Ponton, F 2015, 'Tissue-Specific Immune Gene Expression in the Migratory Locust, Locusta Migratoria.', Insects, vol. 6, no. 2, pp. 368-380.View/Download from: UTS OPUS or Publisher's site
The ability of hosts to respond to infection involves several complex immune recognition pathways. Broadly conserved pathogen-associated molecular patterns (PAMPs) allow individuals to target a range of invading microbes. Recently, studies on insect innate immunity have found evidence that a single pathogen can activate different immune pathways across species. In this study, expression changes in immune genes encoding peptidoglycan-recognition protein SA (PGRP-SA), gram-negative binding protein 1 (GNBP1) and prophenoloxidase (ProPO) were investigated in Locusta migratoria, following an immune challenge using injected lipopolysaccharide (LPS) solution from Escherichia coli. Since immune activation might also be tissue-specific, gene expression levels were followed across a range of tissue types. For PGRP-SA, expression increased in response to LPS within all seven of the tissue-types assayed and differed significantly between tissues. Expression of GNBP1 similarly varied across tissue types, yet showed no clear expression difference between LPS-injected and uninfected locusts. Increases in ProPO expression in response to LPS, however, could only be detected in the gut sections. This study has revealed tissue-specific immune response to add a new level of complexity to insect immune studies. In addition to variation in recognition pathways identified in previous works, tissue-specificity should be carefully considered in similar works.
Schliep, M, Pernice, M, Sinutok, S, Bryant, CV, York, PH, Rasheed, MA & Ralph, PJ 2015, 'Evaluation of Reference Genes for RT-qPCR Studies in the Seagrass Zostera muelleri Exposed to Light Limitation', SCIENTIFIC REPORTS, vol. 5.View/Download from: UTS OPUS or Publisher's site
Nielsen, DA, Pernice, M, Schliep, M, Sablok, G, Jeffries, TC, Kuehl, M, Wangpraseurt, D, Ralph, PJ & Larkum, AWD 2015, 'Microenvironment and phylogenetic diversity of Prochloron inhabiting the surface of crustose didemnid ascidians', ENVIRONMENTAL MICROBIOLOGY, vol. 17, no. 10, pp. 4121-4132.View/Download from: UTS OPUS or Publisher's site
Pernice, M & Levy, O 2014, 'Novel tools integrating metabolic and gene function to study the impact of the environment on coral symbiosis', Frontiers in Microbiology, vol. 5, pp. 1-6.View/Download from: UTS OPUS or Publisher's site
The symbiotic dinoflagellates (genus Symbiodinium) inhabiting coral endodermal tissues are well known for their role as keystone symbiotic partners, providing corals with enormous amounts of energy acquired via photosynthesis and the absorption of dissolved nutrients. In the past few decades, corals reefs worldwide have been increasingly affected by coral bleaching (i.e., the breakdown of the symbiosis between corals and their dinoflagellate symbionts), which carries important socio-economic implications. Consequently, the number of studies focusing on the molecular and cellular processes underlying this biological phenomenon has grown rapidly, and symbiosis is now widely recognized as a major topic in coral biology. However, obtaining a clear image of the interplay between the environment and this mutualistic symbiosis remains challenging. Here, we review the potential of recent technological advances in molecular biology and approaches using stable isotopes to fill critical knowledge gaps regarding coral symbiotic function. Finally, we emphasize that the largest opportunity to achieve the full potential in this field arises from the integration of these technological advances.
Pernice, M, Simpson, S & Ponton, F 2014, 'Towards an integrated understanding of gut microbiota using insects as model systems', Journal of Insect Physiology, vol. 69, pp. 12-18.View/Download from: UTS OPUS or Publisher's site
Metazoans form symbioses with microorganisms that synthesize essential nutritional compounds and increase their efficiency to digest and absorb nutrients. Despite the growing awareness that microbes within the gut play key roles in metabolism, health and development of metazoans, symbiotic relationships within the gut are far from fully understood. Insects, which generally harbor a lower microbial diversity than vertebrates, have recently emerged as potential model systems to study these interactions. In this review, we give a brief overview of the characteristics of the gut microbiota in insects in terms of low diversity but high variability at intra- and interspecific levels and we investigate some of the ecological and methodological factors that might explain such variability. We then emphasize how studies integrating an array of techniques and disciplines have the potential to provide new understanding of the biology of this micro eco-system.
Kopp, C, Pernice, M, Domart-Coulon, I, Djediat, C, Spangenberg, JE, Alexander, DTL, Hignette, M, Meziane, T & Meibom, A 2013, 'Highly Dynamic Cellular-Level Response of Symbiotic Coral to a Sudden Increase in Environmental Nitrogen', MBIO, vol. 4, no. 3.View/Download from: UTS OPUS or Publisher's site
Dunn, SR, Pernice, M, Green, K, Hoegh-Guldberg, O & Dove, SG 2012, 'Thermal Stress Promotes Host Mitochondrial Degradation in Symbiotic Cnidarians: Are the Batteries of the Reef Going to Run Out?', PLOS ONE, vol. 7, no. 7.View/Download from: UTS OPUS or Publisher's site
Pernice, M & Boucher-Rodoni, R 2012, 'Occurrence of a specific dual symbiosis in the excretory organ of geographically distant Nautiloids populations', ENVIRONMENTAL MICROBIOLOGY REPORTS, vol. 4, no. 5, pp. 504-511.View/Download from: UTS OPUS or Publisher's site
Pernice, M, Meibom, A, Van Den Heuvel, A, Kopp, C, Domart-Coulon, I, Hoegh-Guldberg, O & Dove, S 2012, 'A single-cell view of ammonium assimilation in coral-dinoflagellate symbiosis', ISME JOURNAL, vol. 6, no. 7, pp. 1314-1324.View/Download from: UTS OPUS or Publisher's site
Pernice, M, Dunn, SR, Miard, T, Dufour, S, Dove, S & Hoegh-Guldberg, O 2011, 'Regulation of Apoptotic Mediators Reveals Dynamic Responses to Thermal Stress in the Reef Building Coral Acropora millepora', PLOS ONE, vol. 6, no. 1.View/Download from: UTS OPUS or Publisher's site
Ponton, F, Chapuis, M-P, Pernice, M, Sword, GA & Simpson, SJ 2011, 'Evaluation of potential reference genes for reverse transcription-qPCR studies of physiological responses in Drosophila melanogaster', JOURNAL OF INSECT PHYSIOLOGY, vol. 57, no. 6, pp. 840-850.View/Download from: UTS OPUS or Publisher's site
Rosic, NN, Pernice, M, Dove, S, Dunn, S & Hoegh-Guldberg, O 2011, 'Gene expression profiles of cytosolic heat shock proteins Hsp70 and Hsp90 from symbiotic dinoflagellates in response to thermal stress: possible implications for coral bleaching', CELL STRESS & CHAPERONES, vol. 16, no. 1, pp. 69-80.View/Download from: UTS OPUS or Publisher's site
Rosic, NN, Pernice, M, Rodriguez-Lanetty, M & Hoegh-Guldberg, O 2011, 'Validation of Housekeeping Genes for Gene Expression Studies in Symbiodinium Exposed to Thermal and Light Stress', MARINE BIOTECHNOLOGY, vol. 13, no. 3, pp. 355-365.View/Download from: UTS OPUS or Publisher's site
Rosic, NN, Pernice, M, Dunn, S, Dove, S & Hoegh-Guldberg, O 2010, 'Differential Regulation by Heat Stress of Novel Cytochrome P450 Genes from the Dinoflagellate Symbionts of Reef-Building Corals', APPLIED AND ENVIRONMENTAL MICROBIOLOGY, vol. 76, no. 9, pp. 2823-2829.View/Download from: UTS OPUS or Publisher's site
Pernice, M, Boucher, J, Boucher-Rodoni, R, Joannot, P & Bustamante, P 2009, 'Comparative bioaccumulation of trace elements between Nautilus pompilius and Nautilus macromphalus (Cephalopoda: Nautiloidea) from Vanuatu and New Caledonia', ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY, vol. 72, no. 2, pp. 365-371.View/Download from: UTS OPUS or Publisher's site
Quevrain, E, Domart-Coulon, I, Pernice, M & Bourguet-Kondracki, M-L 2009, 'Novel natural parabens produced by a Microbulbifer bacterium in its calcareous sponge host Leuconia nivea', ENVIRONMENTAL MICROBIOLOGY, vol. 11, no. 6, pp. 1527-1539.View/Download from: UTS OPUS or Publisher's site
Pernice, M, Destoumieux-Garzon, D, Peduzzi, J, Rebuffat, S & Boucher-Rodoni, R 2007, 'Identification of a Vibrio strain producing antimicrobial agents in the excretory organs of Nautilus pompilius (Cephalopoda : Nautiloidea)', REVIEWS IN FISH BIOLOGY AND FISHERIES, vol. 17, no. 2-3, pp. 197-205.View/Download from: UTS OPUS or Publisher's site
Pernice, M, Pichon, D, Domart-Coulon, I, Favet, J & Boucher-Rodoni, R 2007, 'Primary co-culture as a complementary approach to explore the diversity of bacterial associations in marine invertebrates: the example of Nautilus macromphalus (Cephalopoda : Nautiloidea)', MARINE BIOLOGY, vol. 150, no. 5, pp. 749-757.View/Download from: Publisher's site
Pernice, M, Wetzel, S, Gros, O, Boucher-Rodoni, R & Dubilier, N 2007, 'Enigmatic dual symbiosis in the excretory organ of Nautilus macromphalus (Cephalopoda : Nautiloidea)', PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, vol. 274, no. 1614, pp. 1143-1152.View/Download from: Publisher's site
Larkum, AWD, Pernice, M, Schliep, M, Davey, P, Szabo, M, Raven, JA, Lichtenberg, M, Brodersen, KE & Ralph, PJ 2018, 'Photosynthesis and metabolism of seagrasses' in Seagrasses of Australia: Structure, Ecology and Conservation, Springer, Switzerland, pp. 315-342.View/Download from: UTS OPUS or Publisher's site
© Springer International Publishing AG, part of Springer Nature 2018. Seagrasses have a unique leaf morphology where the major site for chloroplasts is in the epidermal cells, stomata are absent and aerenchyma is present inside the epidermis. This means that the major site for photosynthesis is in the epidermis. Furthermore the lack of stomata means that the route for carbon uptake is via inorganic carbon (C i ) uptake across the vestigial cuticle and through the outer plasma membranes. Since the leaf may at times be in an unstirred situation diffusion through an unstirred layer outside the leaf may be a large obstacle to carbon uptake. The existence of a carbon concentrating mechanism is discussed, but its existence to date is not proven. Active bicarbonate uptake across the plasmalemma does not seem to operate; an external carbonic anhydrase and an extrusion of protons seem to play a role in enhancing CO 2 uptake. There is some evidence that a C4 mechanism plays a role in carbon fixation but more evidence from "omics" is required. Photorespiration certainly occurs in seagrasses and an active xanthophyll cycle is present to cope with damaging high light, but both these biochemical mechanisms need further work. Finally, epiphytes pose a problem which impedes the uptake of C i and modifies the light environment inside the leaves.
Pernice, M, Schliep, M, Szabo, M, Rasheed, M, Bryant, C, York, P, Chartrand, K & Petrou, K 2015, Development of a molecular biology tool kit to monitor dredging-related light stress in the seagrass Zostera muelleri ssp. capricorniin Port Curtis - final report, no. 15/08, Cairns.View/Download from: UTS OPUS
Roberts, C, Pernice, M & Nicastro, A 2014, Bimonthly Coral Monitoring Report: Dredging Report 6 − Ichthys Nearshore Environmental Monitoring Program., no. 6, pp. 1-294, Sydney.View/Download from: UTS OPUS
Roberts, C, Pernice, M & Nicastro, A 2014, Bimonthly Coral Monitoring Report: Dredging Report 7 − Ichthys Nearshore Environmental Monitoring Program., no. 7, pp. 1-234, Sydney.View/Download from: UTS OPUS
Blount, C, Alderson, B, Roberts, C, Cummings, D, Pernice, M & Neilson, J 2013, Bimonthly Coral Monitoring Report: Dredging Baseline Report − Ichthys Nearshore Environmental Monitoring Program, pp. 1-258, Sydney.View/Download from: UTS OPUS
Blount, C, Roberts, C, Cummings, D, Pernice, M, Neilson, J & Nicastro, A 2013, Bimonthly Coral Monitoring Report: Dredging Report 2 − Ichthys Nearshore Environmental Monitoring Program, no. 2, pp. 1-126, Sydney.View/Download from: UTS OPUS
Pernice, M, Roberts, C & Nicastro, A 2013, Bimonthly Coral Monitoring Report: Dredging Report 5 − Ichthys Nearshore Environmental Monitoring Program., no. 5, pp. 1-204, Sydney.View/Download from: UTS OPUS
Roberts, C, Pernice, M & Nicastro, A 2013, Bimonthly Coral Monitoring Report: Dredging Report 3 − Ichthys Nearshore Environmental Monitoring Program., no. 3, pp. 1-154, Sydney.View/Download from: UTS OPUS
Roberts, C, Pernice, M & Nicastro, A 2013, Bimonthly Coral Monitoring Report: Dredging Report 4 − Ichthys Nearshore Environmental Monitoring Program., no. 4, pp. 1-177, Sydney.View/Download from: UTS OPUS
New South Wales Department of Primary Industries, GE healthcare.