Biology subjects

Matz, M. V.

Publications and source records attributed to Matz, M. V..

24 records · Page 2Linked to original sources

bioRxiv2019

Predicting coral adaptation to global warming in the Indo-West-Pacific

The potential of reef-building corals to adapt to increasing sea surface temperatures is often speculated about but has rarely been comprehensively modeled on a region-wide scale. Here, we used individual-based simulations to model adaptation to warming in a coral metapopulation comprising 680 reefs and representing the whole of the Central Indo-West Pacific. We find that in the first century of warming (approximately from 50 years ago to 50 years in the future) corals adapt rapidly by redistributing pre-existing adaptive alleles among populations (\"genetic rescue\"). In this way, some coral populations - most notably, Vietnam, Japan, Taiwan, New Caledonia, and the southern half of the Great Barrier Reef - appear to be able to maintain their fitness even under the worst warming scenarios (at least in theory, assuming the rate of evolution is the only limitation to local coral recovery). Still, survival of the majority of reefs in the region critically depends on the warming rate, underscoring the urgent need to curb carbon emissions. Conveniently, corals adaptive potential was largely independent of poorly known genetic parameters and could be predicted based on a simple metric derived from the biophysical connectivity model: the proportion of recruits immigrating from warmer locations. We have confirmed that this metric correlates with actual coral cover changes throughout the region, based on published reef survey data from the 1970s to early 2000s. The new metric allows planning assisted gene flow interventions to facilitate adaptation of specific coral populations.

evolutionary biology↗

bioRxiv2019

Positive genetic associations among fitness traits support evolvability of a reef-building coral under multiple stressors

Climate change threatens organisms in a variety of interactive ways that requires simultaneous adaptation of multiple traits. Predicting evolutionary responses requires an understanding of the potential for synergistic interactions among stressors and the genetic variance and covariance among fitness-related traits that may reinforce or constrain an adaptive response. Here we investigate the capacity of Acropora millepora, a reef-building coral, to adapt to multiple environmental stressors: rising sea surface temperature, ocean acidification, and increased prevalence of infectious diseases. We measured growth rates (weight gain), coral color (a proxy for Symbiodiniaceae density), and survival, in addition to nine physiological indicators of coral and algal health in 40 coral genets exposed to each of these three stressors singly and combined. Individual stressors resulted in predicted responses (e.g., corals developed lesions after bacterial challenge and bleached under thermal stress). However, corals did not suffer substantially more when all three stressors were combined. Nor were tradeoffs observed between tolerances to different stressors; instead, individuals performing well under one stressor also tended to perform well under every other stressor. An analysis of genetic correlations between traits revealed positive co-variances, suggesting that selection to multiple stressors will reinforce rather than constrain the simultaneous evolution of traits related to holobiont health (e.g., weight gain and algal density). These findings support the potential for rapid coral adaptation under climate change and emphasize the importance of accounting for corals adaptive capacity when predicting the future of coral reefs.

evolutionary biology↗

bioRxiv2018

Recruit symbiosis establishment and Symbiodiniceae composition influenced by adult corals and reef sediment

For most reef-building corals, the establishment of symbiosis occurs via horizontal transmission, where juvenile coral recruits acquire their algal symbionts (family Symbiodiniaceae) from their surrounding environment post-settlement. This transmission strategy allows corals to interact with a diverse array of symbionts, potentially facilitating adaptation to the newly settled environment. We exposed aposymbiotic Pseudodiploria strigosa recruits from the Flower Garden Banks to natal reef sediment (C-S+), symbiotic adult coral fragments (C+S-), sediment and coral fragments (C+S+), or seawater controls (C-S-) and quantified rates of symbiont uptake and Symbiodiniaceae community composition within each recruit using metabarcoding of the ITS2 locus. The most rapid uptake was observed in C+S+ treatments and this combination also led to the highest symbiont alpha diversity in recruits. While C-S+ treatments exhibited the next highest uptake rate, only one individual recruit successfully established symbiosis in the C+S-treatment, suggesting that sediment both serves as a direct symbiont source for coral recruits and promotes (or, potentially, mediates) transmission from adult coral colonies. In turn, presence of adult corals facilitated uptake from the sediment, perhaps via chemical signaling. Taken together, our results reinforce the key role of sediment in algal symbiont uptake by P. strigosa recruits and suggest that sediment plays a necessary, but perhaps not sufficient, role in the life cycle of the algal Symbiodinaceae symbionts.

zoology↗

bioRxiv2017

Patterns of gene body methylation predict coral fitness in new environments

Despite widespread taxonomic representation, the function of gene body methylation (GBM) remains uncertain. One hypothesis is that GBM mediates phenotypic plasticity. To investigate this hypothesis, we performed whole-genome methylation and transcriptome profiling on reciprocally transplanted colony fragments of the reef-building coral Acropora millepora. GBM was only slightly affected by transplantation but these small changes correlated with coral fitness in the new environment. Specifically, for transplanted corals, similarity in GBM patterns to native corals positively correlated with growth rate, as well as carbohydrate, protein, lipid and endosymbiont content. Between populations, elevated GBM positively correlated with transcription, supporting previous findings that GBM is associated with stable and active transcription. Contrary to expectations however, changes in transcription as a result of transplantation did not correlate with changes in GBM and did not predict fitness. This indicates that on physiological time scales GBM is not directly coupled to transcription, leaving open the question about the mechanism linking GBM to fitness during acclimatization.

ecology↗

bioRxiv2017

Fantastic beasts and how to sequence them: genomic approaches for obscure model organisms.

Application of genomic approaches to \"obscure model organisms\" (OMOs), meaning species with little or no genomic resources, enables increasingly sophisticated studies of genomic basis of evolution, acclimatization and adaptation in real ecological contexts. Here, I highlight sequencing solutions and data handling techniques most suited for genomic analysis of OMOs.\n\nGlossary- Allele Frequency Spectrum, AFS (same as Site Frequency Spectrum, SFS): histogram of the number of segregating variants depending on their frequency in one or more populations.\n- Restriction site-Associated DNA (RAD) sequencing: family of diverse genotyping methods that sequence short fragments of the genome adjacent to recognition site(s) for specific restriction endonuclease(s).\n- Linkage Disequilibrium (LD): in this review, correlation of genotypes at a pair of markers across individuals.\n- LD block: typical distance between markers in the genome across which their genotypes remain correlated.\n- Genome scan: profiling of genotypes along the genome looking for unusual patterns. Often used to look for signatures of natural selection or introgression.\n- \"Denser-than-LD\" genotyping: genotyping of several polymorphic markers per LD block.\n- Highly contiguous reference: genome or transcriptome reference sequence containing the least amount of fragmentation.\n- Phased data: data showing which SNP alleles belong to the same homologous chromosome copy.\n- Cross-tissue gene expression analysis: looking for individual-specific shifts in gene expression detectable across multiple tissues. Such shifts are predominantly genetic in nature.

genomics↗

bioRxiv2017

Adaptive pathways of coral populations on the Great Barrier Reef

Can genetic adaptation in reef-building corals keep pace with the current rate of sea surface warming? Here we combine population genomic, biophysical modeling, and evolutionary simulations to predict future adaptation of the common coral Acropora millepora on the Great Barrier Reef. Loss of coral cover in recent decades did not yet have detectable effect on genetic diversity in our species. Genomic analysis of migration patterns closely matched the biophysical model of larval dispersal in favoring the spread of existing heat-tolerant alleles from lower to higher latitudes. Given these conditions we find that standing genetic variation could be sufficient to fuel rapid adaptation of A. millepora to warming for the next 100-200 years, although random thermal anomalies would drive increasingly severe mortality episodes. However, this adaptation will inevitably cease unless the warming is slowed down, since no realistic mutation rate could replenish adaptive genetic variation fast enough.

evolutionary biology↗