Biology subjects

Ickert-Bond, S. M.

Publications and source records attributed to Ickert-Bond, S. M..

3 recordsLinked to original sources

bioRxiv2025

Enabling the Study of Gene Function in Gymnosperms: VIGS in Ephedra tweedieana

PremiseAs the sister clade to angiosperms, gymnosperms are key to enabling the reconstruction of ancestral gene regulatory networks for seed plants. However, tools to rapidly and efficiently investigate gene function in gymnosperms remain limited due to the challenges of long life cycles and large genome sizes. Species within the xerophytic genus Ephedra (Gnetales) have comparatively smaller genomes and shrubby growth habits with shorter life spans, making them better suited for greenhouse cultivation and laboratory experiments. Methods and ResultsHere, we implement Virus-Induced Gene Silencing (VIGS) to manipulate gene expression in Ephedra tweedieana. Agrobacterium-mediated vacuum infiltration of Tobacco Rattle Virus (TRV2 and TRV1) in seedlings resulted in highly efficient silencing of the E. tweedieana PHYTOENE DESATURASE ortholog EtwPDS. The expected photobleaching phenotype was observed as early as two weeks. It lasted at least three months, in stems, shoot tips, leaves, axillary meristems, and lateral branches of treated plants. ConclusionsThis first report of transient transformation and targeted gene silencing in a gymnosperm will further enable functional studies of the genetic mechanisms underpinning adaptations in this important and underrepresented lineage of seed plants.

plant biology↗

bioRxiv2020

Population genomic and historical analysis reveals a global invasion by bridgehead processes in Mimulus guttatus

Humans are transforming species ranges worldwide. While artificial translocations trigger biological invasions with negative effects on biodiversity, invasions provide exceptional opportunities to generate ecological and evolutionary hypotheses. Unfortunately, imperfect historical records and exceedingly complex demographic histories present challenges for the reconstruction of invasion histories. Here we combine historical records, extensive worldwide and genome-wide sampling, and demographic analyses to investigate the global invasion of yellow monkeyflowers (Mimulus guttatus) from North America to Europe and the Southwest Pacific. By sampling 521 plants from 158 native and introduced populations genotyped at >44,000 loci, we determined that invasive North American M. guttatus was first likely introduced to the British Isles from the Aleutian Islands (Alaska), followed by rapid admixture from multiple parts of the native range. Populations in the British Isles then appear to have served as a bridgehead for vanguard invasions worldwide into the rest of Europe, New Zealand and eastern North America. Our results emphasise the highly admixed nature of introduced M. guttatus and demonstrate the potential of introduced populations to serve as sources of secondary admixture, producing novel hybrids. Unravelling the history of biological invasions provides a starting point to understand how invasive populations adapt to novel environments.

evolutionary biology↗

bioRxiv2020

A target enrichment probe set for resolving the flagellate plant tree of life

Premise of the studyNew sequencing technologies enable the possibility of generating large-scale molecular datasets for constructing the plant tree of life. We describe a new probe set for target enrichment sequencing to generate nuclear sequence data to build phylogenetic trees with any flagellate plants, comprising hornworts, liverworts, mosses, lycophytes, ferns, and gymnosperms. Methods and ResultsWe leveraged existing transcriptome and genome sequence data to design a set of 56,989 probes for target enrichment sequencing of 451 nuclear exons and non-coding flanking regions across flagellate plant lineages. We describe the performance of target enrichment using the probe set across flagellate plants and demonstrate the potential of the data to resolve relationships among both ancient and closely related taxa. ConclusionsA target enrichment approach using the new probe set provides a relatively low-cost solution to obtain large-scale nuclear sequence data for inferring phylogenetic relationships across flagellate plants.

evolutionary biology↗