共查询到20条相似文献，搜索用时 15 毫秒
1.
C. D. Kenkel G. Goodbody‐Gringley D. Caillaud S. W. Davies E. Bartels M. V. Matz 《Molecular ecology》2013,22(16):4335-4348
Studying the mechanisms that enable coral populations to inhabit spatially varying thermal environments can help evaluate how they will respond in time to the effects of global climate change and elucidate the evolutionary forces that enable or constrain adaptation. Inshore reefs in the Florida Keys experience higher temperatures than offshore reefs for prolonged periods during the summer. We conducted a common garden experiment with heat stress as our selective agent to test for local thermal adaptation in corals from inshore and offshore reefs. We show that inshore corals are more tolerant of a 6‐week temperature stress than offshore corals. Compared with inshore corals, offshore corals in the 31 °C treatment showed significantly elevated bleaching levels concomitant with a tendency towards reduced growth. In addition, dinoflagellate symbionts (Symbiodinium sp.) of offshore corals exhibited reduced photosynthetic efficiency. We did not detect differences in the frequencies of major (>5%) haplotypes comprising Symbiodinium communities hosted by inshore and offshore corals, nor did we observe frequency shifts (‘shuffling’) in response to thermal stress. Instead, coral host populations showed significant genetic divergence between inshore and offshore reefs, suggesting that in Porites astreoides, the coral host might play a prominent role in holobiont thermotolerance. Our results demonstrate that coral populations inhabiting reefs <10‐km apart can exhibit substantial differences in their physiological response to thermal stress, which could impact their population dynamics under climate change. 相似文献
2.
3.
C. D. Kenkel C. Sheridan M. C. Leal R. Bhagooli K. D. Castillo N. Kurata E. McGinty T. L. Goulet M. V. Matz 《Molecular ecology resources》2014,14(4):667-678
Gene expression biomarkers can enable rapid assessment of physiological conditions in situ, providing a valuable tool for reef managers interested in linking organism physiology with large‐scale climatic conditions. Here, we assessed the ability of quantitative PCR (qPCR)‐based gene expression biomarkers to evaluate (i) the immediate cellular stress response (CSR) of Porites astreoides to incremental thermal stress and (ii) the magnitude of CSR and cellular homeostasis response (CHR) during a natural bleaching event. Expression levels largely scaled with treatment temperature, with the strongest responses occurring in heat‐shock proteins. This is the first demonstration of a ‘tiered’ CSR in a coral, where the magnitude of expression change is proportional to stress intensity. Analysis of a natural bleaching event revealed no signature of an acute CSR in normal or bleached corals, indicating that the bleaching stressor(s) had abated by the day of sampling. Another long‐term stress CHR‐based indicator assay was significantly elevated in bleached corals, although assay values overall were low, suggesting good prospects for recovery. This study represents the first step in linking variation in gene expression biomarkers to stress tolerance and bleaching thresholds in situ by quantifying the severity of ongoing thermal stress and its accumulated long‐term impacts. 相似文献
4.
5.
Mathieu G. Séré Pablo Tortosa Pascale Chabanet Jean‐Pascal Quod Michael J. Sweet Michael H. Schleyer 《Molecular ecology》2015,24(17):4570-4581
Porites white patch syndrome (PWPS) is a coral disease recently described in the Western Indian Ocean. This study aimed to isolate and identify potential pathogens associated with PWPS utilizing both culture and nonculture screening techniques and inoculation trials. A total of 14 bacterial strains (those dominant in disease lesions, absent or rare in healthy tissues and considered potential pathogens in a previous study) were cultured and used to experimentally inoculate otherwise healthy individuals in an attempt to fulfil Henle–Koch's postulates. However, only one (P180R), identified as closely related (99–100% sequence identity based on 1.4 kb 16S RNA sequence) to Vibrio tubiashii, elicited signs of disease in tank experiments. Following experimental infection (which resulted in a 90% infection rate), the pathogen was also successfully re‐isolated from the diseased tissues and re‐inoculated in healthy corals colonies, therefore fulfilling the final stages of Henle–Koch's postulates. Finally, we report that PWPS appears to be a temperature‐dependent disease, with significantly higher tissue loss (anova : d.f. = 2, F = 39.77, P < 0.01) occurring at 30 °C [1.45 ± 0.85 cm2 per day (mean ± SE)] compared to ambient temperatures of 28 and 26 °C (0.73 ± 0.80 cm2 per day (mean ± SE) and 0.51 ± 0.50 cm2 per day (mean ± SE), respectively). 相似文献
6.
7.
Maryam Nasr Esfahani Saad Sulieman Joachim Schulze Kazuko Yamaguchi‐Shinozaki Kazuo Shinozaki Lam‐Son Tran 《Plant biotechnology journal》2014,12(3):387-397
Chickpea (Cicer arietinum) is an important pulse crop in many countries in the world. The symbioses between chickpea and Mesorhizobia, which fix N2 inside the root nodules, are of particular importance for chickpea's productivity. With the aim of enhancing symbiotic efficiency in chickpea, we compared the symbiotic efficiency of C‐15, Ch‐191 and CP‐36 strains of Mesorhizobium ciceri in association with the local elite chickpea cultivar ‘Bivanij’ as well as studied the mechanism underlying the improvement of N2 fixation efficiency. Our data revealed that C‐15 strain manifested the most efficient N2 fixation in comparison with Ch‐191 or CP‐36. This finding was supported by higher plant productivity and expression levels of the nifHDK genes in C‐15 nodules. Nodule specific activity was significantly higher in C‐15 combination, partially as a result of higher electron allocation to N2 versus H+. Interestingly, a striking difference in nodule carbon and nitrogen composition was observed. Sucrose cleavage enzymes displayed comparatively lower activity in nodules established by either Ch‐191 or CP‐36. Organic acid formation, particularly that of malate, was remarkably higher in nodules induced by C‐15 strain. As a result, the best symbiotic efficiency observed with C‐15‐induced nodules was reflected in a higher concentration of the total and several major amino metabolites, namely asparagine, glutamine, glutamate and aspartate. Collectively, our findings demonstrated that the improved efficiency in chickpea symbiotic system, established with C‐15, was associated with the enhanced capacity of organic acid formation and the activities of the key enzymes connected to the nodule carbon and nitrogen metabolism. 相似文献
8.
W.‐M. Xiao M.‐C. Zhao M. Zou Y.‐D. Tan X.‐G. Zhang 《Plant biology (Stuttgart, Germany)》2014,16(3):539-549
9.
Stefanie Pontasch Paul L. Fisher Thomas Krueger Sophie Dove Ove Hoegh‐Guldberg William Leggat Simon K. Davy 《Journal of phycology》2017,53(2):308-321
Corals at the world's southernmost coral reef of Lord Howe Island (LHI) experience large temperature and light fluctuations and need to deal with periods of cold temperature (<18°C), but few studies have investigated how corals are able to cope with these conditions. Our study characterized the response of key photophysiological parameters, as well as photoacclimatory and photoprotective pigments (chlorophylls, xanthophylls, and β‐carotene), to short‐term (5‐d) cold stress (~15°C; 7°C below control) in three LHI coral species hosting distinct Symbiodinium ITS2 types, and compared the coral–symbiont response to that under elevated temperature (~29°C; 7°C above control). Under cold stress, Stylophora sp. hosting Symbiodinium C118 showed the strongest effects with regard to losses of photochemical performance and symbionts. Pocillopora damicornis hosting Symbiodinium C100/C118 showed less severe bleaching responses to reduced temperature than to elevated temperature, while Porites heronensis hosting Symbiodinium C111* withstood both reduced and elevated temperature. Under cold stress, photoprotection in the form of xanthophyll de‐epoxidation increased in unbleached P. heronensis (by 178%) and bleached Stylophora sp. (by 225%), while under heat stress this parameter increased in unbleached P. heronensis (by 182%) and in bleached P. damicornis (by 286%). The xanthophyll pool size was stable in all species at all temperatures. Our comparative study demonstrates high variability in the bleaching vulnerability of these coral species to low and high thermal extremes and shows that this variability is not solely determined by the ability to activate xanthophyll de‐epoxidation. 相似文献
10.
11.
Marina Telonis‐Scott Allannah S. Clemson Travis K. Johnson Carla M. Sgrò 《Molecular ecology》2014,23(24):6135-6151
12.
13.
Robert van Woesik Peter Houk Adelle L. Isechal Jacques W. Idechong Steven Victor Yimnang Golbuu 《Ecology and evolution》2012,2(10):2474-2484
Coral bleaching and mortality are predicted to increase as climate change‐induced thermal‐stress events become more frequent. Although many studies document coral bleaching and mortality patterns, few studies have examined deviations from the expected positive relationships among thermal stress, coral bleaching, and coral mortality. This study examined the response of >30,000 coral colonies at 80 sites in Palau, during a regional thermal‐stress event in 2010. We sought to determine the spatial and taxonomic nature of bleaching and examine whether any habitats were comparatively resistant to thermal stress. Bleaching was most severe in the northwestern lagoon, in accordance with satellite‐derived maximum temperatures and anomalous temperatures above the long‐term averages. Pocillopora populations suffered the most extensive bleaching and the highest mortality. However, in the bays where temperatures were higher than elsewhere, bleaching and mortality were low. The coral‐community composition, constant exposure to high temperatures, and high vertical attenuation of light caused by naturally high suspended particulate matter buffered the corals in bays from the 2010 regional thermal‐stress event. Yet, nearshore reefs are also most vulnerable to land‐use change. Therefore, nearshore reefs should be given high conservation status because they provide refugia for coral populations as the oceans continue to warm. 相似文献
14.
Cornelia Roder Chatchanit Arif Camille Daniels Ernesto Weil Christian R. Voolstra 《Molecular ecology》2014,23(4):965-974
Coral diseases are characterized by microbial community shifts in coral mucus and tissue, but causes and consequences of these changes are vaguely understood due to the complexity and dynamics of coral‐associated bacteria. We used 16S rRNA gene microarrays to assay differences in bacterial assemblages of healthy and diseased colonies displaying White Plague Disease (WPD) signs from two closely related Caribbean coral species, Orbicella faveolata and Orbicella franksi. Analysis of differentially abundant operational taxonomic units (OTUs) revealed strong differences between healthy and diseased specimens, but not between coral species. A subsequent comparison to data from two Indo‐Pacific coral species (Pavona duerdeni and Porites lutea) revealed distinct microbial community patterns associated with ocean basin, coral species and health state. Coral species were clearly separated by site, but also, the relatedness of the underlying bacterial community structures resembled the phylogenetic relationship of the coral hosts. In diseased samples, bacterial richness increased and putatively opportunistic bacteria were consistently more abundant highlighting the role of opportunistic conditions in structuring microbial community patterns during disease. Our comparative analysis shows that it is possible to derive conserved bacterial footprints of diseased coral holobionts that might help in identifying key bacterial species related to the underlying etiopathology. Furthermore, our data demonstrate that similar‐appearing disease phenotypes produce microbial community patterns that are consistent over coral species and oceans, irrespective of the putative underlying pathogen. Consequently, profiling coral diseases by microbial community structure over multiple coral species might allow the development of a comparative disease framework that can inform on cause and relatedness of coral diseases. 相似文献
15.
Cait A. McDonald Ana V. Longo Karen R. Lips Kelly R. Zamudio 《Molecular ecology》2020,29(17):3173-3186
As globalization lowers geographic barriers to movement, coinfection with novel and enzootic pathogens is increasingly likely. Novel and enzootic pathogens can interact synergistically or antagonistically, leading to increased or decreased disease severity. Here we examine host immune responses to coinfection with two closely related fungal pathogens: Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). Both pathogens have had detrimental effects on amphibian populations, with Bd now largely enzootic, while Bsal is currently spreading and causing epizootics. Recent experimental work revealed that newts coinfected with Bd and Bsal had significantly higher mortality than those infected with either pathogen alone. Here we characterize host immunogenomic responses to chytrid coinfection relative to single infection. Across several classes of immune genes including pattern recognition receptors, cytokines, and MHC, coinfected host gene expression was weakly upregulated or comparable to that seen in single Bd infection, but significantly decreased when compared to Bsal infection. Combined with strong complement pathway downregulation and keratin upregulation, these results indicate that coinfection with Bd and Bsal compromises immune responses active against Bsal alone. As Bsal continues to invade naïve habitats where Bd is enzootic, coinfection will be increasingly common. If other Bd‐susceptible species in the region have similar responses, interactions between the two pathogens could cause severe population and community‐level declines. 相似文献
16.
T. Hagi M. Kobayashi S. Kawamoto J. Shima M. Nomura 《Journal of applied microbiology》2013,114(6):1763-1771
Aims
To determine whether the carotenoid production improves stress tolerance of lactic acid bacteria, the cloned enterococcal carotenoid biosynthesis genes were expressed in Lactococcus lactis ssp. cremoris MG1363, and the survival rate of carotenoid‐producing engineered MG1363 strain under stress condition was investigated.Methods and Results
We cloned carotenoid biosynthesis genes from yellow‐pigmented Enterococcus gilvus. The cloned genes consisted of crtN and crtM and its promoter region were inserted into the shuttle vector pRH100, and the resulting plasmid was named pRC. The cloned crtNM was expressed using pRC in noncarotenoid‐producing L. lactis ssp. cremoris MG1363. The expression of crtNM led to the production of C30 carotenoid 4,4′‐diaponeurosporene. After exposure to 32 mmol l?1 H2O2, low pH (1.5, acidified with HCl), 20% bile acid and 12 mg ml?1 lysozyme, the survival rates of the MG1363 strain harbouring pRC were 18.7‐, 6.8‐, 8.8‐ and 4.4‐fold higher, respectively, than those of MG1363 strain harbouring the empty vector pRH100.Conclusions
The expression of carotenoid biosynthesis genes from Ent. gilvus improves the multistress tolerance of L. lactis.Significance and Impact of the study
First report of the improvement of multistress tolerance of lactic acid bacteria by the introduction of genes for carotenoid production. 相似文献17.
Carly D. Kenkel Aurelie Moya Julia Strahl Craig Humphrey Line K. Bay 《Global Change Biology》2018,24(1):158-171
Little is known about the potential for acclimatization or adaptation of corals to ocean acidification and even less about the molecular mechanisms underpinning these processes. Here, we examine global gene expression patterns in corals and their intracellular algal symbionts from two replicate population pairs in Papua New Guinea that have undergone long‐term acclimatization to natural variation in pCO2. In the coral host, only 61 genes were differentially expressed in response to pCO2 environment, but the pattern of change was highly consistent between replicate populations, likely reflecting the core expression homeostasis response to ocean acidification. Functional annotations highlight lipid metabolism and a change in the stress response capacity of corals as key parts of this process. Specifically, constitutive downregulation of molecular chaperones was observed, which may impact response to combined climate change‐related stressors. Elevated CO2 has been hypothesized to benefit photosynthetic organisms but expression changes of in hospite Symbiodinium in response to acidification were greater and less consistent among reef populations. This population‐specific response suggests hosts may need to adapt not only to an acidified environment, but also to changes in their Symbiodinium populations that may not be consistent among environments, adding another challenging dimension to the physiological process of coping with climate change. 相似文献
18.
19.
20.
Congrui Wang Venkata Ajay Narendra Talabattula Zhikun Guo Arndt Rolfs Jiankai Luo 《Development, growth & differentiation》2013,55(3):368-376
Members of the ADAM (a disintegrin and metalloprotease) family are type I transmembrane proteins involved in biological processes of proteolysis, cell adhesion, cell–matrix interaction, as well as in the intracellular signaling transduction. In the present study, expression patterns of seven members of the ADAM family were investigated at the early stages of the developing cochlea by in situ hybridization. The results show that each individual ADAM is expressed and regulated in the early developing cochlea. ADAM9, ADAM10, ADAM17, and ADAM23 are initially and widely expressed in the otic vesicle at embryonic day 2.5 (E2.5) and in the differential elements of the cochlear duct at E9, while ADAM12 is expressed in acoustic ganglion cells at E7. ADAM22 is detectable in cochlear ganglion cells as early as from E4 and in the basilar papilla from E7. Therefore, the present study extends our previous results and suggests that ADAMs also play a role in the early cochlear development. 相似文献