Biology subjects

Williamson, K.

Publications and source records attributed to Williamson, K..

3 recordsLinked to original sources

bioRxiv2021

Integrating genomics and multi-platform metabolomics enables metabolite QTL detection in breeding-relevant apple germplasm

Research ConductedApple (Malus x domestica) has commercial and nutritional value, but breeding constraints of tree crops limit varietal improvement. Marker-assisted selection minimizes these drawbacks, but breeders lack applications for targeting fruit phytochemicals. To understand genotype-phytochemical associations in apples, we have developed a high-throughput integration strategy for genomic and multi-platform metabolomics data. Methods124 apple genotypes, including members of three pedigree-connected breeding families alongside diverse cultivars and wild selections, were genotyped and phenotyped. Metabolite genome-wide association studies (mGWAS) were conducted with 10,000 single nucleotide polymorphisms and phenotypic data acquired via LC-MS and 1H NMR untargeted metabolomics. Putative metabolite quantitative trait loci (mQTL) were then validated via pedigree-based analyses (PBA). Key ResultsUsing our developed method, 519, 726, and 177 putative mQTL were detected in LC-MS positive and negative ionization modes and NMR, respectively. mQTL were indicated on each chromosome, with hotspots on linkage groups 16 and 17. A chlorogenic acid mQTL was discovered on chromosome 17 via mGWAS and validated with a two-step PBA, enabling discovery of novel candidate gene-metabolite relationships. Main ConclusionComplementary data from three metabolomics approaches and dual genomics analyses increased confidence in validity of compound annotation and mQTL detection. Our platform demonstrates the utility of multi-omics integration to advance data-driven, phytochemicalbased plant breeding.

plant biology↗

bioRxiv2020

Moderate and intensive mechanical loading differentially modulate the phenotype of tendon stem/progenitor cells in vivo

To examine the differential mechanobiological responses of specific resident tendon cells, we developed an in vivo model of whole-body irradiation followed by injection of either tendon stem/progenitor cells (TSCs) expressing green fluorescent protein (GFP-TSCs) or mature tenocytes expressing GFP (GFP-TNCs) into the patellar tendons of wild type C57 mice. Injected mice were subjected to moderate treadmill running (MTR) and intensive treadmill running (ITR). In MTR mice, both GFP-TSC and GFP-TNC injected tendons maintained normal cell morphology with elevated expression of tendon related markers collagen I and tenomodulin. In ITR mice injected with GFP-TNCs, cells also maintained an elongated shape similar to the shape found in normal/untreated control mice, as well as elevated expression of tendon related markers. However, ITR mice injected with GFP-TSCs showed typical tendinopathic changes, such as cell morphology transitioning to a round shape, elevated chondrogenic differentiation, and increased gene expression of non-tenocyte related genes LPL, Runx-2, and SOX-9. Increased gene expression data was supported by immunostaining showing elevated expression of SOX-9, Runx-2, and PPAR{gamma}. This study provides evidence that while MTR maintains tendon homeostasis by promoting the differentiation of TSCs into tenocytes, ITR may cause the development of tendinopathy by inducing non-tenocyte differentiation of TSCs, thus leading to the presence of non-tendinous tissues in tendon.

cell biology↗

bioRxiv2020

Active synthesis of collagen (I) homotrimer and matrisomal proteins in Dupuytren's fibrosis

Dupuytrens disease is a common fibroproliferative disease of the palmar fascia of the hand with advanced cases treated surgically. Anti-tumour necrosis factor (TNF) injection has undergone phase 2 trials and may be effective in slowing early-stage disease progression. Here we sought to determine how new synthesis of type I collagen in Dupuytrens differs from normal palmar fascia samples and to analyse the role of TNF in aberrant collagen synthesis. Model non-fibrotic, but fibrous connective tissues, were used to analyse active type I collagen protein synthesis in development, ageing and degenerative disease, where it was restricted to early development and ruptured tissue. Dupuytrens tissue was shown to actively synthesise type I collagen, including abnormal type I collagen homotrimer. TNF- reduced COL1A2 gene expression only in the presence of serum in 2D cell culture and had opposing effects on collagen protein production in the presence or absence of serum. TNF- had only limited effects in 3D tendon-like constructs. Anti-TNF did not reduce type I collagen synthesis in 3D tendon-like constructs or prevent type I collagen homotrimer synthesis in Dupuytrens tissue. Hence, modulation of the TNF- pathway in Dupuytrens disease is unlikely to prevent the pathological collagen accumulation that is characteristic of fibrosis.

cell biology↗