scholarly journals Fast and pervasive transcriptomic resilience and acclimation of extremely heat-tolerant coral holobionts from the northern Red Sea

2021 ◽  
Vol 118 (19) ◽  
pp. e2023298118
Author(s):  
Romain Savary ◽  
Daniel J. Barshis ◽  
Christian R. Voolstra ◽  
Anny Cárdenas ◽  
Nicolas R. Evensen ◽  
...  

Corals from the northern Red Sea and Gulf of Aqaba exhibit extreme thermal tolerance. To examine the underlying gene expression dynamics, we exposed Stylophora pistillata from the Gulf of Aqaba to short-term (hours) and long-term (weeks) heat stress with peak seawater temperatures ranging from their maximum monthly mean of 27 °C (baseline) to 29.5 °C, 32 °C, and 34.5 °C. Corals were sampled at the end of the heat stress as well as after a recovery period at baseline temperature. Changes in coral host and symbiotic algal gene expression were determined via RNA-sequencing (RNA-Seq). Shifts in coral microbiome composition were detected by complementary DNA (cDNA)-based 16S ribosomal RNA (rRNA) gene sequencing. In all experiments up to 32 °C, RNA-Seq revealed fast and pervasive changes in gene expression, primarily in the coral host, followed by a return to baseline gene expression for the majority of coral (>94%) and algal (>71%) genes during recovery. At 34.5 °C, large differences in gene expression were observed with minimal recovery, high coral mortality, and a microbiome dominated by opportunistic bacteria (including Vibrio species), indicating that a lethal temperature threshold had been crossed. Our results show that the S. pistillata holobiont can mount a rapid and pervasive gene expression response contingent on the amplitude and duration of the thermal stress. We propose that the transcriptomic resilience and transcriptomic acclimation observed are key to the extraordinary thermal tolerance of this holobiont and, by inference, of other northern Red Sea coral holobionts, up to seawater temperatures of at least 32 °C, that is, 5 °C above their current maximum monthly mean.

2020 ◽  
Author(s):  
Christian Voolstra ◽  
Jacob Valenzuela ◽  
Serdar Turkarslan ◽  
Anny Cardenas ◽  
Benjamin Hume ◽  
...  

Abstract Corals from the northern Red Sea, in particular the Gulf of Aqaba (GoA), have exceptionally high bleaching thresholds approaching >5°C above their maximum monthly mean (MMM) temperatures. These elevated thresholds are thought to be due to historical selection, as corals passed through the warmer Southern Red Sea during re-colonization from the Arabian Sea. To test this hypothesis, we determined thermal tolerance thresholds of GoA versus Central Red Sea (CRS) Stylophora pistillata corals using the Coral Bleaching Automated Stress System (CBASS) to run a series of standardized acute thermal stress assays. Relative thermal thresholds of GoA and CRS corals were indeed similar and exceptionally high (~7°C above MMM). However, absolute thermal thresholds of CRS corals were on average 3°C above those of GoA corals. To explore the mechanistic underpinnings, we determined gene expression response and microbiome dynamics of coral holobiont compartments. Transcriptomic responses differed markedly, with a strong response to the thermal stress in GoA corals versus a remarkably muted response in corals from the CRS. This pattern was recapitulated in the algal symbionts that showed site-specific genetic differentiation. Concomitant to this, a subset of coral and algal genes showed temperature-induced expression in GoA corals, while exhibiting fixed high expression, i.e. front-loading, in CRS corals. Bacterial community composition of GoA corals changed dramatically under heat stress, whereas CRS corals displayed consistent assemblages, indicating distinct microbial response patterns. Our work demonstrates distinct patterns underlying thermal tolerance across spatial scales, even for the same species and ocean basin. We interpret the response of GoA corals as that of a resilient population approaching a tipping point in contrast to a pattern of consistently elevated thermal resistance in CRS corals that cannot further attune. Such response differences suggest distinct thermal tolerance mechanisms that affect the response of coral populations to ocean warming.


2018 ◽  
Vol 82 (3) ◽  
pp. 169
Author(s):  
Ronald Fricke ◽  
Daniel Golani ◽  
Brenda Appelbaum-Golani ◽  
Uwe Zajonz

The scorpionfish Scorpaena decemradiata n. sp. is described from off the coast of Israel in the Gulf of Aqaba, northern Red Sea. The new species is similar to S. porcus Linnaeus, 1758, but is characterized by dorsal fin spines XII, soft dorsal fin rays 10 (the last divided at base); pectoral fin rays 16, uppermost branched pectoral fin ray is the second; lacrimal with 2 spines over maxilla that point at nearly right angle from each other, the posterior pointing ventrally and slightly anteriorly; occipital pit well developed; anteriormost mandibular lateral-line pores small, separated; scales ctenoid; 59-62 scale rows in longitudinal series; scales absent on chest and pectoral fin base; and cirri developed over entire head and body, but no cirri on lower jaw. An updated checklist of the species of the genus Scorpaena Linnaeus, 1758 and a key to the species of the eastern Atlantic, Mediterranean Sea and Red Sea are presented.


2019 ◽  
Author(s):  
Maritere Urioistegui-Arcos ◽  
Rodrigo Aguayo-Ortiz ◽  
María del Pilar Valencia-Morales ◽  
Erika Melchy-Pérez ◽  
Yvonne Rosenstein ◽  
...  

AbstractDisruption of the enzymatic activities of the transcription factor TFIIH by Triptolide (TPL) or THZ1 could be used against cancer. Here, we used an oncogenesis model to compare the effect of TFIIH inhibitors between transformed cells and their progenitors. We report that tumour cells exhibited highly increased sensitivity to TPL or THZ1 and that the combination of both had an additive effect. TPL affects the interaction between XPB and P52, causing a reduction in the levels of XPB, P52, and P8, but not other TFIIH subunits. RNA-Seq and RNAPII-ChIP-Seq experiments showed that although the levels of many transcripts were reduced, the levels of a significant number were increased after TPL treatment, with maintained or increased RNAPII promoter occupancy. A significant number of these genes encode for factors that have been related to tumour growth and metastasis. Some of these genes were also overexpressed in response to THZ1, which depletion enhances the toxicity of TPL and are possible new targets against cancer.


Zootaxa ◽  
2005 ◽  
Vol 859 (1) ◽  
pp. 1 ◽  
Author(s):  
TAMER HELMY ◽  
ROB W.M. VAN SOEST

Amphimedon (Porifera, Demospongiae, Haplosclerida, Niphatidae), a pantropical genus of reef and mangrove sponges, was recently recorded for the first time from the Red Sea suggesting a rarity which is not sustained by new reef surveys in the Gulf of Aqaba. Here we describe four species of Amphimedon occurring commonly in the Gulf of Aqaba. Among these, three are new to science, A. dinae sp.nov., A. jalae sp.nov. and A. hamadai sp.nov., the fourth one has been recently described as A. chloros Ilan et al., 2004. Although the latter species and our three new species are the first definite Ampimedon species recorded from the Red Sea, at least one previously described sponge from the region, Ceraochalina ochracea Keller, 1889 is suspected to belong to this genus as well. The status of the described and suspected Red Sea Amphimedon is discussed and compared to species recorded from neighbouring Indian Ocean waters.


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