Esser, E. A. | bioRxiv Science

bioRxiv2024

Nanoparticles alter the nature and strength of intraploidy and interploidy interactions in plants

Engineered nanoparticles have profound impacts on organisms, yet there is limited understanding of how nanoparticle exposure shapes species interactions that are key for natural community dynamics. By growing plants of the same (intraploidy) and different ploidy levels (interploidy) of Fragaria in axenic microcosms, we examined the influence of nanoparticles on species interactions in polyploid and diploid plants. We found that, under copper oxide (CuO) nanoparticle exposure, polyploids experienced reduced competition when growing with polyploids (the effect of polyploids on polyploids, RII8x,8x), and a shift towards facilitation when growing with diploids (the effect of diploids on polyploids, RII8x,2x). This reduction in competitive interactions in polyploids, in line with the stress gradient hypothesis, was primarily caused by nanoscale effects, because the strength of competitive interactions (RII8x,8x and RII8x,2x) remained relatively unchanged under CuO bulk particles compared to control conditions. In contrast, diploids experienced a shift from facilitation (RII2x,2x and RII2x,8x) under control conditions to neutrality under CuO nanoparticles, with a similar reduction in facilitation observed with both nanoparticles and bulk particles. These findings underscore ploidy specific interaction dynamics and the need of considering species interactions when predicting organismal responses to nanoparticle pollution in ecological communities.

ecology↗

bioRxiv2023

A new cell culture resource for investigations of reptilian gene function

The recent establishment of CRISPR/Cas9 gene editing in A. sagrei lizards makes it a powerful model system for studies of reptilian gene function. To enhance the versatility of this model, we developed an immortalized lizard fibroblast cell line (ASEC-1) for the exploration of reptilian gene function in cellular processes. We demonstrate the use of this in vitro system by scrutinizing the role of primary cilia in lizard Hedgehog (Hh) signaling. Through CRISPR/Cas9 mutagenesis we disrupted the ift88 gene, which is required for ciliogenesis in diverse organisms. We find that the loss of itf88 from lizard cells results in an absence of primary cilia, a partial derepression of gli1 transcription, and an inability of the cells to respond to the Smoothened agonist, SAG. Through a cross-species analysis of SAG-induced transcriptional responses in cultured limb bud cells, we further determined that [~]46% of genes induced as a response to Hh pathway activation in A. sagrei, are also SAG-responsive in M. musculus limb bud cells. Our results highlight conserved and diverged aspects of Hh signaling in anoles and establish a new resource for investigations of reptilian gene function.

developmental biology↗