Biology subjects

Hendrickson, B.

Publications and source records attributed to Hendrickson, B..

4 recordsLinked to original sources

bioRxiv2026

Herbarium genomics reveal signatures of colonization history, lineage turnover, and adaptation during invasion

O_LIA key challenge in invasion biology is dissecting the roles of colonization history, admixture, and selection on invasion success. However, it is often difficult to determine the sources and locations of introduction events as well as the timing and magnitude of gene flow and selection using genomics datasets from contemporary samples. C_LIO_LIWe disentangle the evolutionary processes acting during the North American invasion of Trifolium repens (white clover) using low-coverage whole genome sequencing from 513 herbarium specimens originally collected between 1838-2018. C_LIO_LIIntroduction history paralleled European colonization patterns. The earliest collected samples had predominantly Belgian and British ancestry, with increasing French and Spanish contributions over time in the Mid-Atlantic and South. Genomic diversity increased significantly through time likely driven by admixture between independently introduced lineages. In lowest latitude regions, there is a strong shift in dominant ancestry with limited admixture (i.e., lineage turnover). Putatively adaptive loci exhibited protracted shifts in allele frequency during the invasion, consistent with contemporary clines. C_LIO_LIOur study demonstrates the power of herbarium genomics to provide spatiotemporal insight into recent evolutionary history. We find a complex invasion history that includes multiple introductions, lineage turnover, and admixture that increased genetic diversity and likely facilitated adaptation in this now cosmopolitan plant. C_LI

plant biology↗

bioRxiv2024

Climatic determinants of plant phenology in vernal pool habitats

Vernal pool plants are small, colorful, and specialized to both desiccated and inundated conditions that distinguish the ephemeral wetlands in which they grow. These species germinate rapidly in response to the first rain and grow quickly to take advantage of available water supplies. The floral phenology of vernal pool plant species is little understood despite being a crucial developmental stage for producing seeds and determining population growth rates. The current study focuses on two vernal pool plants, Limnanthes douglasii ssp. rosea (meadowfoam), a vernal pool specialist, and Trifolium variegatum (whitetip clover), a generalist vernal pool associate, and characterizes their phenology in response to interannual climate variation. We recorded phenology and climate data over seven years during a period of highly variable precipitation and temperature patterns, which serve as a robust dataset for quantifying the relationship of floral phenology with various climatic factors. We found that warmer and drier environmental conditions occurring during early growth periods were strongly associated with advanced floral phenology later in the life cycle for both species. Over the seven-year dataset, which was increasingly warm and dry, phenology advanced by 4.7 days per year for meadowfoam and 5.6 days per year for whitetip clover, respectively. The floral duration of the habitat specialist was influenced by microtopographic features of vernal pools, whereas no such patterns were observed for the habitat generalist. Finally, warmer and drier conditions were associated with reduced occupancy rates of both focal species within vernal pools. To our knowledge, this is the first study quantifying the relationship between vernal pool floral phenology and climate, offering insights into how phenology may shift in response to modern climate change.

plant biology↗

bioRxiv2023

Haplotype-resolved, chromosome-level assembly of white clover (Trifolium repens L., Fabaceae)

BackgroundWhite clover (Trifolium repens L.; Fabaceae) is an important forage and cover crop in agricultural pastures around the world, and is increasingly used in evolutionary ecology and genetics to understand the genetic basis of adaptation. Historically, improvements in white clover breeding practices and assessments of genetic variation in nature have been hampered by a lack of high-quality genomic resources for this species, owing in part to its high heterozygosity and allotetraploid hybrid origin. FindingsHere, we use PacBio HiFi and chromosome conformation capture (Omni-C) technologies to generate a chromosome-level, haplotype-resolved genome assembly for white clover totaling 998 Mbp (scaffold N50 = 59.3 Mbp) and 1 Gbp (scaffold N50 = 58.6 Mbp) for haplotypes 1 and 2, respectively, with each haplotype arranged into 16 chromosomes (8 per subgenome). We additionally provide a functionally annotated haploid mapping assembly (968 Mbp, scaffold N50 = 59.9 Mbp), which drastically improves on the existing reference assembly in both contiguity and assembly accuracy. We annotated 78,174 protein-coding genes, resulting in protein BUSCO completeness scores of 99.6% and 99.3% against the embryophyta_odb10 and fabales_odb10 lineage datasets, respectively. ConclusionsWe provide two white clover genome assemblies as part of this project: (1) a haplotype-resolved, chromosome-level assembly, and (2) a functionally annotated haploid mapping assembly. These assemblies place white clover among the best sequenced legumes to date, and one of the best assemblies for a plant of recent polyploid origins. This work promises to facilitate ongoing and future work in agricultural and evolutionary genetics in this agronomically and ecologically important species.

genomics↗

bioRxiv2019

CEP290 myosin-tail homology domain is essential for protein confinement between inner and outer segments in photoreceptors

Mutations in CEP290 cause various ciliopathies involving retinal degeneration. CEP290 proteins localize to the ciliary transition zone and are thought to act as a gatekeeper that controls ciliary protein trafficking. However, precise roles of CEP290 in photoreceptors and pathomechanisms of retinal degeneration in CEP290-associated ciliopathies are not sufficiently understood. Using Cep290 conditional mutant mice, in which the C-terminal myosin-tail homology domain is disrupted after the connecting cilium is assembled, we show that CEP290, more specifically the myosin-tail homology domain of CEP290, is essential for protein confinement between the inner and the outer segments. Inner segment plasma membrane proteins including STX3, SNAP25, and IMPG2 rapidly accumulate in the outer segment upon disruption of the myosin-tail homology domain. In contrast, localization of endomembrane proteins is not altered. Trafficking and confinement of most outer segment-resident proteins appear to be unaffected or only minimally affected in this mouse model. One notable exception is RHO, which exhibits severe mislocalization to inner segments from the initial stage of degeneration. Similar mislocalization phenotypes were observed in rd16 mice. These results suggest that failure of protein confinement at the connecting cilium and consequent accumulation of inner segment membrane proteins in the outer segment combined with insufficient RHO delivery is part of the disease mechanisms that cause retinal degeneration in CEP290-associated ciliopathies. Our study provides insights into the pathomechanisms of retinal degenerations associated with compromised ciliary gates.

cell biology↗