Biology subjects

Hutchins, L.

Publications and source records attributed to Hutchins, L..

3 recordsLinked to original sources

bioRxiv2026

Topography structures of arthropod communities revealed by leaf-derived environmental DNA on Oahu, Hawaii

Arthropod communities on oceanic islands are shaped by spatial isolation, environmental gradients, and biological invasions, yet their structure remains difficult to resolve due to incomplete taxonomic coverage. In particular, it remains unclear (i) how non-native arthropods can influence community composition and (ii) how they interact with native and non-native plants. To answer the first question, we used leaf-derived environmental DNA (eDNA) to characterize arthropod communities across elevational gradients on five ridges on Oahu, using the native tree Metrosideros polymorpha as a standardized plant. To understand the second question, we compared leaf-derived eDNA from Metrosideros polymorpha (Native), Acacia koa (native), and Psidium cattleianum (invasive), co-occurring in two ridges on Oahu. Additionally, to overcome limitations of reference databases, we applied NIClassify to infer native versus introduced status without requiring species-level identification. Across 96 leaf samples (with 851 Arthropod ASVs), we found arthropod richness increased with elevation, while the proportion of introduced taxa declined significantly. Community composition was primarily structured by ridge, with strong distance-decay relationships indicating high spatial turnover in both native and non-native assemblages. In contrast, plant species effects were context dependent and did not show a consistent native versus invasive signal. Threshold analyses identified a community transition (native vs introduced) near 500 m elevation. These results show that plant-derived eDNA can resolve spatial and environmental structuring of arthropod communities while capturing invasion dynamics under incomplete taxonomic knowledge. Classifier-based inference enables community-level ecological interpretation beyond reference-limited taxa, providing a scalable framework for biodiversity monitoring in data-poor systems.

ecology↗

bioRxiv2022

Multiple paths towards repeated phenotypic evolution in the spiny-leg adaptive radiation (Tetragnatha; Hawaii)

The repeated evolution of phenotypes is ubiquitous in nature and offers some of the clearest evidence of the role of natural selection in evolution. The genomic basis of repeated phenotypic evolution is often complex and can arise from a combination of gene flow, shared ancestral polymorphism and de novo mutation. Here, we investigate the genomic basis of repeated ecomorph evolution in the adaptive radiation of the Hawaiian spiny-leg Tetragnatha. This radiation comprises four ecomorphs that are microhabitat-specialists, and differ in body pigmentation and size (Green, Large Brown, Maroon, and Small Brown). Using 76 newly generated low-coverage, whole-genome resequencing samples, coupled with population genomic and phylogenomic tools, we studied the evolutionary history of the radiation to understand the evolution of the spiny-leg lineage and the genetic underpinnings of ecomorph evolution. Congruent with previous works, we find that each ecomorph has evolved twice, with the exception of the Small Brown ecomorph, which has evolved three times. The evolution of the Maroon and the Small Brown ecomorphs likely involved ancestral hybridization events, whereas the Green and the Large Brown ecomorphs likely evolved because of either standing genetic variation or de novo mutation. Pairwise comparisons of ecomorphs based on the fixation index (FST) show that divergent genomic regions include genes with functions associated with pigmentation (melanization), learning, neuronal and synapse activity, and circadian rhythms. These results show that the repeated evolution of ecomorphs in the Hawaiian spiny-leg Tetragnatha is linked to multiple genomic regions and suggests a previously unknown role of learning and circadian rhythms in ecomorph.

evolutionary biology↗

bioRxiv2019

Klf9 is a key feedforward regulator of the transcriptomic response to glucocorticoid receptor activity

The zebrafish has recently emerged as a model system for investigating the developmental roles of glucocorticoid signaling and the mechanisms underlying glucocorticoid-induced developmental programming. To assess the role of the Glucocorticoid Receptor (GR) in such programming, we used CRISPR-Cas9 to produce a new frameshift mutation, GR369-, which eliminates all potential in-frame initiation codons upstream of the DNA binding domain. Using RNA-seq to ask how this mutation affects the larval transcriptome under both normal conditions and with chronic cortisol treatment, we find that GR mediates most of the effects of the treatment, and paradoxically, that the transcriptome of cortisol-treated larvae is more like that of larvae lacking a GR than that of larvae with a GR, suggesting that the cortisol-treated larvae develop GR resistance. The one transcriptional regulator that was both underexpressed in GR369- larvae and consistently overexpressed in cortisol-treated larvae was klf9. We therefore used CRISPR-Cas9-mediated mutation of klf9 and RNA-seq to assess Klf9-dependent gene expression in both normal and cortisol-treated larvae. Our results indicate that Klf9 contributes significantly to the transcriptomic response to chronic cortisol exposure, mediating the upregulation of proinflammatory genes that we reported previously.

developmental biology↗