scholarly journals Effects of temperature, season and locality on wasting disease in the keystone predatory sea star Pisaster ochraceus

2009 ◽  
Vol 86 ◽  
pp. 245-251 ◽  
Author(s):  
AE Bates ◽  
BJ Hilton ◽  
CDG Harley
Keyword(s):  
Sea Star ◽  
Wasting Disease ◽  
Pisaster Ochraceus ◽  
Effects Of Temperature

scholarly journals Virome Variation during Sea Star Wasting Disease Progression in Pisaster ochraceus (Asteroidea, Echinodermata)

Viruses ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1332
Author(s):  
Ian Hewson ◽  
Citlalli A. Aquino ◽  
Christopher M. DeRito
Keyword(s):  
Viral Genome ◽  
Marine Invertebrates ◽  
Scar Tissue ◽  
Sea Star ◽  
Wasting Disease ◽  
Viral Genomes ◽  
Normal Tissues ◽  
Pisaster Ochraceus ◽  
Affected Tissue ◽  
External Stimuli

Sea star wasting disease (SSWD) is a condition that has affected asteroids for over 120 years, yet mechanistic understanding of this wasting etiology remains elusive. We investigated temporal virome variation in two Pisaster ochraceus specimens that wasted in the absence of external stimuli and two specimens that did not experience SSWD for the duration of our study, and compared viromes of wasting lesion margin tissues to both artificial scar margins and grossly normal tissues over time. Global assembly of all SSWD-affected tissue libraries resulted in 24 viral genome fragments represented in >1 library. Genome fragments mostly matched densoviruses and picornaviruses with fewer matching nodaviruses, and a sobemovirus. Picornavirus-like and densovirus-like genome fragments were most similar to viral genomes recovered in metagenomic study of other marine invertebrates. Read recruitment revealed only two picornavirus-like genome fragments that recruited from only SSWD-affected specimens, but neither was unique to wasting lesions. Wasting lesion margin reads recruited to a greater number of viral genotypes (i.e., richness) than did either scar tissue and grossly normal tissue reads. Taken together, these data suggest that no single viral genome fragment was associated with SSWD. Rather, wasting lesion margins may generally support viral proliferation.

scholarly journals Virome Temporal Variation During Sea Star Wasting Disease Progression in Pisaster ochraceus (Asteroidea, Echinodermata)

2020 ◽  
Author(s):  
Ian Hewson ◽  
Citlalli A. Aquino ◽  
Christopher M. DeRito
Keyword(s):  
Viral Genome ◽  
Marine Invertebrates ◽  
Scar Tissue ◽  
Sea Star ◽  
Wasting Disease ◽  
Viral Genomes ◽  
Normal Tissues ◽  
Pisaster Ochraceus ◽  
Affected Tissue ◽  
External Stimuli

Sea star wasting disease (SSWD) is a condition that has affected asteroids for over 120 years, yet mechanistic understanding of wasting etiology remains elusive. We investigated temporal virome variation in two Pisaster ochraceus specimens that wasted in the absence of external stimuli and two specimens that did not experience SSWD for the duration of our study, and compared viromes of wasting lesion margin tissues to both artificial scar margins and grossly normal tissues over time. Global assembly of all SSWD-affected tissue libraries resulted in 45 viral genome fragments represented in >1 library. Genome fragments mostly matched densoviruses and picornaviruses with fewer matching nodaviruses, narnaviruses and sobemoviruses. Picornavirus-like and densovirus-like genome fragments were most similar to viral genomes recovered in metagenomic study of other marine invertebrates. Read recruitment revealed only 2 picornavirus-like genome fragments that recruited from only SSWD-affected specimens, but neither was unique to wasting lesions. Wasting lesion margin reads recruited to a greater number of viral genotypes (i.e. richness) than did either scar tissue and grossly normal tissue reads. Taken together, these data suggest that no single viral genome fragment was associated with SSWD. Rather, wasting lesion margins may generally support viral proliferation.

scholarly journals RNA expression and disease tolerance are associated with a “keystone mutation” in the ochre sea star Pisaster ochraceus

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3696 ◽  
Author(s):  
V. Katelyn Chandler ◽  
John P. Wares
Keyword(s):  
Cellular Response ◽  
Constitutive Expression ◽  
Elongation Factor ◽  
Sea Star ◽  
Wasting Disease ◽  
Pisaster Ochraceus ◽  
The Pacific ◽  
Response To Temperature ◽  
Elongation Factor 1 ◽  
Lower Expression

An overdominant mutation in an intron of the elongation factor 1-α (EF1A) gene in the sea star Pisaster ochraceus has shown itself to mediate tolerance to “sea star wasting disease”, a pandemic that has significantly reduced sea star populations on the Pacific coast of North America. Here we use RNA sequencing of healthy individuals to identify differences in constitutive expression of gene regions that may help explain this tolerance phenotype. Our results show that individuals carrying this mutation have lower expression at a large contingent of gene regions. Individuals without this mutation also appear to have a greater cellular response to temperature stress, which has been implicated in the outbreak of sea star wasting disease. Given the ecological significance of P. ochraceus, these results may be useful in predicting the evolutionary and demographic future for Pacific intertidal communities.

scholarly journals Decimation by sea star wasting disease and rapid genetic change in a keystone species, Pisaster ochraceus

2018 ◽  
Vol 115 (27) ◽  
pp. 7069-7074 ◽  
Author(s):  
Lauren M. Schiebelhut ◽  
Jonathan B. Puritz ◽  
Michael N Dawson
Keyword(s):  
Population Dynamics ◽  
Allele Frequency ◽  
Keystone Species ◽  
Allele Frequencies ◽  
Sea Star ◽  
Sequencing Data ◽  
Wasting Disease ◽  
Genomic Change ◽  
Study Region ◽  
Pisaster Ochraceus

Standing genetic variation enables or restricts a population’s capacity to respond to changing conditions, including the extreme disturbances expected to increase in frequency and intensity with continuing anthropogenic climate change. However, we know little about how populations might respond to extreme events with rapid genetic shifts, or how population dynamics may influence and be influenced by population genomic change. We use a range-wide epizootic, sea star wasting disease, that onset in mid-2013 and caused mass mortality in Pisaster ochraceus to explore how a keystone marine species responded to an extreme perturbation. We integrated field surveys with restriction site-associated DNA sequencing data to (i) describe the population dynamics of mortality and recovery, and (ii) compare allele frequencies in mature P. ochraceus before the disease outbreak with allele frequencies in adults and new juveniles after the outbreak, to identify whether selection may have occurred. We found P. ochraceus suffered 81% mortality in the study region between 2012 and 2015, and experienced a concurrent 74-fold increase in recruitment beginning in late 2013. Comparison of pre- and postoutbreak adults revealed significant allele frequency changes at three loci, which showed consistent changes across the large majority of locations. Allele frequency shifts in juvenile P. ochraceus (spawned from premortality adults) were consistent with those seen in adult survivors. Such parallel shifts suggest detectable signals of selection and highlight the potential for persistence of this change in subsequent generations, which may influence the resilience of this keystone species to future outbreaks.

scholarly journals Reciprocal abundance shifts of the intertidal sea stars, Evasterias troschelii and Pisaster ochraceus , following sea star wasting disease

2019 ◽  
Vol 286 (1901) ◽  
pp. 20182766 ◽  
Author(s):  
Sharon W. C. Kay ◽  
Alyssa-Lois M. Gehman ◽  
Christopher D. G. Harley
Keyword(s):  
Indirect Effects ◽  
Interference Competition ◽  
Disease Outbreaks ◽  
Ecological Communities ◽  
Population Declines ◽  
Sea Star ◽  
Sea Stars ◽  
Wasting Disease ◽  
Field Surveys ◽  
Pisaster Ochraceus

Disease emergence occurs within the context of ecological communities, and disease driven declines in host populations can lead to complex direct and indirect ecological effects. Varying effects of a single disease among multiple susceptible hosts could benefit relatively resistant species. Beginning in 2013, an outbreak of sea star wasting disease (SSWD) led to population declines of many sea star species along the west coast of North America. Through field surveys and laboratory experiments, we investigated how and why the relative abundances of two co-occurring sea star species, Evasterias troschelii and Pisaster ochraceus , shifted during the ongoing wasting epidemic in Burrard Inlet, British Columbia, Canada. We hypothesized that Evasterias is competitively inferior to Pisaster but more resistant to SSWD. Thus, we predicted that SSWD-induced declines of Pisaster could mitigate the negative effects of SSWD on Evasterias , as the latter would experience competitive release. We document shifts in sea star abundance from 2008–2017: Pisaster abundance and mean size declined during the outbreak, while Evasterias abundance increased from relatively rare to numerically dominant within the intertidal. When exposed to symptomatic sea stars, Pisaster and Evasterias both showed signs of SSWD, but transmission and susceptibility was lower in Evasterias. Despite diet overlap documented in our field surveys, Evasterias was not outcompeted by Pisaster in laboratory trails conducted with the relatively small Pisaster available after the outbreak. Interference competition with larger Pisaster , or prey exploitation by Pisaster during the summer when Evasterias is primarily subtidal, may explain the rarity of Evasterias prior to Pisaster declines. Our results suggest that indirect effects mediated by competition can mask some of the direct effects of disease outbreaks, and the combination of direct and indirect effects will determine the restructuring of a community after disturbance.

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