Biology subjects

Matz, M.

Publications and source records attributed to Matz, M..

5 recordsLinked to original sources

bioRxiv2023

Modifications to gene body methylation does not alter gene expression plasticity in a reef-building coral

As coral reefs continue to decline due to climate change, the role of coral epigenetics (specifically, gene body methylation, GBM) in coral acclimatization warrants investigation. The evidence is currently conflicting. In diverse animal phyla the baseline GBM level is associated with gene function: continuously expressed "housekeeping" genes are typically highly methylated, while inducible context-dependent genes have low or no methylation at all. Some authors report association between GBM and the environment, and interpret this observation as evidence of GBMs role in acclimatization. Yet, others argue that correlation between GBM change and gene expression change is typically absent or negligible. Here, we used the reef- building coral, Acropora millepora, to test whether environmentally driven changes in GBM are associated with a genes ability to respond to environmental changes (plasticity) rather than expression level. We analyzed two cases of modified gene expression plasticity observed in a three-week-long heat acclimatization experiment. The first one was a group of heat-induced genes that failed to revert their expression after the coral was translocated back to the control tank. The second case involved genes that changed the magnitude of their response to the daily temperature fluctuations over the course of the experiment. In both cases we found negligible or no association with GBM change. We conclude that although both gene expression plasticity and GBM can change during acclimatization, there is no direct association between the two. This adds to the increasing volume of evidence that the function of GBM in invertebrates is unrelated to acclimatization on physiological timescales.

evolutionary biology↗

bioRxiv2020

Genomic heritability of song and condition in wild singing mice

Courtship displays are dramatic examples of complex behaviors that vary within and among species. Evolutionary explanations for this diversity rely upon genetic variation, yet the heritability of complex phenotypes is seldom investigated in the field. Here, we estimate genomic heritability of advertisement song and body condition in a wild population of singing mice. The heritability of song exhibits a systematic pattern, with high heritability for spectral characteristics linked to vocal morphology, intermediate heritability for rhythmic patterns, and lower but significant heritability for measures of motivation, like song length and rate. Physiological measures of condition, like hormonal markers of adiposity, exhibited intermediate heritability. Among singing mice, song rate and body condition have a strong phenotypic correlation; our estimate suggests a comparable genetic correlation that merits further study. Our results illustrate how advances in genomics and quantitative genetics can be integrated in free-living species to address longstanding challenges in behavior and evolution.

evolutionary biology↗

bioRxiv2019

Contrasting population genetic structure in Acropora coral hosts and their algal symbionts across multiple spatial scales

Many broadly-dispersing corals acquire their algal symbionts (Symbiodiniaceae) horizontally from their environment upon recruitment. Horizontal transmission could promote coral fitness across diverse environments provided that corals can associate with divergent algae across their range and that these symbionts exhibit reduced dispersal potential. Here we quantified community divergence of Cladocopium algal symbionts in two coral host species (Acropora hyacinthus, Acropora digitifera) across two spatial scales (reefs on the same island, and between islands) across the Micronesian archipelago using microsatellites. We find that both hosts associated with two genetically distinct Cladocopium lineages (C40, C21), confirming that Acropora coral hosts associate with a range of Cladocopium symbionts across this region. Both C40 and C21 exhibited extensive clonality. Clones not only existed across host conspecifics living on the same reef, but also spanned host species, reef sites within islands, and even different islands. Both Cladocopium lineages exhibited moderate host specialization and divergence across islands. In addition, within every island, algal symbiont communities were significantly clustered by both host species and reef site, highlighting that coral-associated Cladocopium communities are structured across small spatial scales and within hosts on the same reef. This is in stark contrast to their coral hosts, which never exhibited significant genetic divergence between reefs on the same island. These results support the view that horizontal transmission could improve local fitness for broadly dispersing Acropora coral species.

ecology↗

bioRxiv2018

Effects of thermal stress on amount, composition, and antibacterial properties of coral mucus

The surface mucus layer of reef-building corals supports several essential functions including feeding, sediment clearing, and protection from pathogenic invaders. For the reef ecosystem, coral mucus provides energy to support heterotrophic benthic communities. Mucus production represents a substantial metabolic investment on behalf of the coral: as much as half of the fixed carbon supplied by the corals algal symbionts is incorporated into expelled mucus. In this study, we examined if bleaching (disruption of the coral-algal symbiosis) has the potential to indirectly disturb reef ecosystem function by impacting the nutritional composition of coral mucus. In a controlled laboratory thermal stress challenge, visibly paled corals produced mucus with higher protein and lipid content and increased antibacterial activity relative to healthy corals. These results are likely explained by the expelled symbionts in the mucus of bleached individuals. This study illuminates how the immediate effects of coral bleaching could impact the reef-ecosystem indirectly through modulation of available nutrients within the ecosystem.

molecular biology↗

bioRxiv2018

Relationship between Acropora millepora juvenile fluorescence and composition of newly established Symbiodinium assemblage

Coral-dinoflagellate symbiosis is the key biological interaction enabling existence of modern-type coral reefs, but the mechanisms regulating initial host-symbiont attraction, recognition and symbiont proliferation thus far remain largely unclear. A common reef-building coral, Acropora millepora, displays conspicuous fluorescent polymorphism during all phases of its life cycle, due to the differential expression of fluorescent proteins (FPs) of the green fluorescent protein family. In this study, we examine whether fluorescent variation in young coral juveniles exposed to natural sediments is associated with the uptake of disparate Symbiodinium assemblages determined using ITS-2 deep sequencing. We found that Symbiodinium assemblages varied significantly when redness values varied, specifically in regards to abundances of clades A and C. Whether fluorescence was quantified as a categorical or continuous trait, clade A was found at higher abundances in redder juveniles. These preliminary results suggest juvenile fluorescence may be associated with Symbiodinium uptake, potentially acting as either as an attractant to ecologically specific types or as a mechanism to modulate the internal light environment to control Symbiodinium physiology within the host.

ecology↗