Biology subjects

Deihl, E. W.

Publications and source records attributed to Deihl, E. W..

3 recordsLinked to original sources

bioRxiv2026

Activity-Dependent Postsynaptic Mitochondrial ROS Signaling Drives Avoidance Plasticity in C. elegans

Reactive oxygen species (ROS) are signaling molecules involved in neuronal excitatory function, with mitochondrial ROS (mitoROS) playing key roles in metabolic regulation and stress responses. Studies have shown that neuronal activity upregulates mitoROS production through oxidative phosphorylation, but it remains unclear if and how acute elevations in mitoROS influence synaptic plasticity. Here, we develop an avoidance sensitization paradigm in C. elegans using optogenetic excitation and training of nociceptive ASH neurons to initiate avoidance reversals by downstream activation of the AVA command interneurons. Using this paradigm, we show that the probability of reversal to light stimulation increases 4-hours after optogenetic training, indicating behavioral sensitization. This avoidance sensitization is accompanied by an increase of surface glutamate receptor (GLR-1) levels at ASH-AVA synapses which is dependent on postsynaptic expression of GLR-1 and active transcription. Interestingly, we find that somatic and nerve ring mitochondria produce ROS after optogenetic training. We show that this mitochondrial ROS (mitoROS) peak is dependent on postsynaptic GLR-1 and MCU-1 function during optogenetic training and is necessary for avoidance sensitization. Finally, we demonstrate that postsynaptic signaling by mitoROS in AVA is sufficient to induce avoidance sensitization. Postsynaptic photoactivation of mitochondria-targeted Killer Red in AVA, calibrated to produce the mitoROS peak observed during training, induces avoidance sensitization bypassing optogenetic training and MCU-1 requirement. Our results indicate that activity-dependent mitoROS signaling can instruct synaptic strengthening and directly modulate circuit function and behavior. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/730457v2_ufig1.gif" ALT="Figure 1"> View larger version (113K): org.highwire.dtl.DTLVardef@91f9bborg.highwire.dtl.DTLVardef@1a274b1org.highwire.dtl.DTLVardef@9b394forg.highwire.dtl.DTLVardef@cf8b7d_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2025

Protocol combining RNA interference and regeneration assays in planarian embryos

Planarian flatworms gradually acquire whole-body regeneration abilities during late embryonic and juvenile development. Here we show how to perturb gene function with RNA interference (RNAi) in S. polychroa embryos at developmental stages capable of wound healing following amputation. We describe embryo staging, embryo amputation and double-stranded RNA soaking, phenotype analysis, and techniques for qualitative and quantitative assessment of RNAi knock-down efficacy. This protocol is adaptable for use with embryonic stages amenable to ex vivo culturing and with other embryo-producing flatworm species. For complete details on the use and execution of this protocol, please refer to 1. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=194 SRC="FIGDIR/small/666018v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@d4bf29org.highwire.dtl.DTLVardef@1524f6forg.highwire.dtl.DTLVardef@dd40b0org.highwire.dtl.DTLVardef@1c1f6bf_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗

bioRxiv2024

A low-abundance class of Dicer-dependent siRNAs produced from a variety of features in C. elegans

Canonical small interfering RNAs (siRNAs) are processed from double-stranded RNA (dsRNA) by the endoribonuclease Dicer. siRNAs are found in plants, animals, and some fungi where they associate with Argonautes to direct RNA silencing. In Caenorhabditis elegans, some endogenous small RNAs, such as 22G-RNAs and 26G-RNAs, share certain attributes with canonical siRNAs but exhibit unique characteristics known only to occur in nematodes. For instance, 22G-RNAs do not originate from dsRNA and are not processed by Dicer, whereas 26G-RNAs require Dicer but lack the typical duplex intermediate with symmetrical 3-overhangs and are produced only antisense to their mRNA templates. To identify canonical siRNAs in C. elegans, we first characterized the siRNAs produced from exogenous dsRNA. As predicted based on earlier studies, exogenous dsRNA is processed into [~]23-nt duplexes with 2-4-nt 3-overhangs, ultimately yielding siRNAs devoid of 5 G-containing sequences that bind with high affinity to the Argonaute RDE-1. Leveraging these characteristics, we searched for their endogenous counterparts and identified thousands of endogenous loci representing dozens of unique elements that give rise to mostly low to moderate levels of siRNAs, called 23H-RNAs. These loci include repetitive elements, alleged coding genes, pseudogenes, non-coding RNAs, and unannotated features, many of which adopt hairpin structures reminiscent of the hpRNA/RNA interference (RNAi) pathway in flies and mice. Our results expand the known repertoire of C. elegans small RNAs and demonstrate that key features of the endogenous siRNA pathway are relatively unchanged in animals.

genomics↗