Biology subjects

Durkin, K. M.

Publications and source records attributed to Durkin, K. M..

3 recordsLinked to original sources

bioRxiv2026

Cross-talk among miRNAs, lncRNAs, and DNA methylation in three coral species reveal conserved epigenetic regulatory architecture

Epigenetic mechanisms support phenotypic plasticity across metazoans, enabling dynamic response to environmental change. DNA methylation and non-coding RNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), regulate gene expression through distinct but interconnected mechanisms. In vertebrate systems, these layers form integrated networks in which specific miRNAs directly target the protein machinery of other epigenetic processes ("epi-miRNAs") and specialized lncRNAs act as competing endogenous RNAs (ceRNAs), sequestering miRNAs from their mRNA targets. Whether equivalent cross-layer regulatory architectures exist in cnidarians, whose methylomes are invertebrate-characteristic and whose miRNAs function mechanistically like those of plants, is unknown. Here we integrate matched RNA-seq, small RNA-seq, and whole-genome bisulfite sequencing across three species of reef-building coral (Acropora pulchra, Porites evermanni, and Pocillopora tuahiniensis) to characterize the landscape and regulatory interactions of microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and DNA methylation, including the first description of epi-miRNAs and ceRNA networks in cnidarian taxa. Across the study species, miRNAs putatively targeted transcripts encoding a suite of epigenetic processes, including DNA methylation regulators (TET3, MBD, PRDM14), ubiquitin-signaling and histone-modifying machinery, and components of the miRNA pathway itself (e.g., AGO, TNRC6). The conserved miRNA miR-100 also exhibited species-divergent target coexpression, suggesting lineage-specific regulatory roles for deeply conserved miRNAs. Candidate ceRNA networks were also recovered, including predicted derepression of epimachinery transcripts, indicating that lncRNA-mediated buffering operates alongside direct miRNA control. Recovery of these regulatory interactions across three evolutionarily divergent species, despite few orthologous miRNA or lncRNA, suggests that multi-layered epigenetic regulation is a conserved feature of cnidarian biology. These results establish direct miRNA and lncRNA control of epigenetic machinery as an active component of coral gene regulation, and provide foundational resources for studying how multilayered epigenetic interactions contribute to coral resilience to environmental change. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/739451v1_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@7e07dforg.highwire.dtl.DTLVardef@36cf0forg.highwire.dtl.DTLVardef@5406d3org.highwire.dtl.DTLVardef@8c09e3_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2025

Environmental filtering shapes patch dynamics across isolated mesophotic reefs

Mesophotic coral ecosystems (MCEs; [~]30-150 m) are major but poorly understood benthic habitats. We used Autonomous Reef Monitoring Structures (ARMS) and integrated metabarcoding (mtCOI, 18S), image analysis, and hydrodynamic modeling across six mesophotic banks in the Gulf of Mexico to test whether community assembly is governed by environmental filtering or dispersal limitation. Local environmental conditions explained nearly twice as much compositional variance as geographic effects. Differences in depth and turbidity predicted community dissimilarity up to tenfold better than geographic distance. Turbidity, driven by the benthic nepheloid layer (BNL), was the dominant filter, while depth effects were weaker and taxon-specific. Hydrodynamic simulations revealed dispersal is variable but not limiting. These findings identify the BNL as a key physical driver linking shelf oceanography, biodiversity, and ecosystem function. Suspended particle dynamics associated with BNLs merit integration into conservation planning as critical mediators of ecological connectivity in mesophotic and other patchy reef systems globally. TeaserSuspended particle layers, not dispersal barriers, determines which species colonize mesophotic coral reefs on the TX-LA continental shelf.

ecology↗

bioRxiv2025

Non-coding RNA Repertoire in Reef-Building Corals

Non-coding RNAs (ncRNAs) play critical regulatory roles in gene expression regulation that influences diverse biological processes in response to environmental change. Yet their characterization in non-model organisms, particularly sessile, benthic ecosystem engineers such as reef-building corals that are sensitive to climate change, remains limited. This study provides the first comprehensive analysis of the ncRNA repertoire of species from three ecologically important coral genera from Moorea, French Polynesia: Acropora pulchra, Pocillopora tuahiniensis, and Porites evermanni. These species demonstrate differing symbiotic partners, life history strategies, and physiological traits, offering a broad framework for documenting ncRNA variation in corals. We identified homologs for ncRNA biogenesis and functional machinery, characterized long ncRNAs (lncRNAs), microRNAs (miRNAs), and piwiRNAs (piRNAs), and assessed their genomic context and potential targets. Our findings reveal the presence of conserved ncRNA machinery across these coral species, indicating their capability to generate and utilize ncRNAs for the regulation of gene expression. We identified only a single miRNA conserved with corals and Eumetazoans (miR-100), four miRNAs shared across all three species, previously identified in other cnidarian taxa (miR-100, miR-2023, miR-2025, miR-2036), as well as several species-specific miRNAs. Predicted gene targets of the characterized miRNAs included immune response regulation in A. pulchra and P. tuahiniensis and signal transduction pathways in P. evermanni and P. tuahiniensis. Proximity analysis indicated >71-99% of piRNAs overlapped with genes, with genomic maintenance and stability identified as the primary functional enrichment of those genes. Our characterization of lncRNAs found little sequence overlap across each species (<2%), although lncRNAs in all three species were often in proximity to immune-related genes. This study lays the groundwork for the repertoire and regulatory roles of ncRNAs in reef-building corals, thereby expanding our understanding of epigenetic regulation in environmentally sensitive marine invertebrates and its potential implications in acclimatization and adaptation to environmental change.

molecular biology↗