Biology subjects

Persson, C.

Publications and source records attributed to Persson, C..

4 recordsLinked to original sources

bioRxiv2025

Genomic prediction of agronomic traits in perennial ryegrass (Lolium perenne L.) and genotype x environment interactions at the limit of the species distribution

BackgroundIn breeding the aim is to identify and accumulate beneficial variants. However, detection of these variants may be challenging in the presence of extensive genotype x environment interactions (GxE), as variant effects will be conditional on environment. MethodsThe study assesses the performance of 264 diploid perennial ryegrass accessions in a multi-environment field trial. We investigate the extent of GxE, for yield (total dry matter) and persistence traits, i.e. winter kill and spring cover, under environmental conditions experienced in Nordic and Baltic regions at the limit of the species distribution. Two different approaches to modelling GxE were tested: reaction norm and envirotyping, and the models were validated under three different breeding scenarios. ResultsOur analysis documented the presence of significant GxE interaction for all traits investigated in the study. Validation showed improvements in prediction accuracy when accounting for GxE: up to 4% for yield when predicting in unobserved environments, and up to 22% and 9% for spring cover and winter kill, respectively when predicting unobserved germplasm. Genome-wide-association-studies (GWAS) were utilized to detect genetic variants with marginal effects (environment-independent effect) and conditional effects (environment-dependent effects). Results showed the presence of large-effect genetic variants with marginal effects, in addition to few QTL whose effects were adaptive under specific environmental conditions while neutral or deleterious under different environmental conditions. ConclusionThis study demonstrates the usefulness and limitations of genomic prediction models for predicting GxE in highly diverse samples, and describes the extent of GxE interactions at the limit of species distribution for perennial ryegrass. Finally, our study points toward adaptive variation, which may enhance persistence of perennial ryegrass populations in Nordic and Baltic growing conditions.

genetics↗

bioRxiv2025

Tuning the Mechanical Properties and Printability of Viscoelastic Skin-Derived Hydrogels for 3D Cell Culture

In vitro investigations or tissue engineering require the creation of hierarchical and acellularized 3D structures mimicking the native environment of cells in vivo. Bioprinting provides a powerful approach to fabricating 3D architectures with precision and control. However, developing a bioink suitable for 3D cell culture remains challenging, particularly in achieving optimal rheological properties, printability and bioactivity necessary for cellular viability, functionality and growth. Here, we developed tissue-derived hydrogels with tunable gelation kinetics and rheological properties. By precisely adjusting the bioinks physical characteristics, we optimized its printability for extrusion-based bioprinting, enabling fast fabrication of structurally stable constructs that support the formation of 3D cellular structures. A robust decellularization protocol was developed to consistently obtain porcine skin-derived dECM (decellularized extracellular matrix) hydrogels with minimal batch-to-batch variation. The influence of dECM concentration (1-5 mg/mL) on the inks viscoelastic properties, printability, gelation kinetics, and cellular response was investigated. Gelation kinetics varied between 7 minutes to several hours, while the storage modulus ranged between 10 to 1000 Pa. Additionally, more concentrated hydrogels led to more homogeneous prints due to their higher viscosity. Fibroblast cells infiltrated the 3D matrix of the softer hydrogels (1 and 2.5 mg/mL), forming an interconnected network. In contrast, migration was significantly restricted in the denser hydrogels (5 mg/mL). Our findings demonstrate the potential of tissue-derived hydrogels with tunable properties for 3D bioprinting applications, enabling fast and reproducible fabrication of dECM environments for cellular studies and tissue engineering, while highlighting the critical balance between mechanical and biological properties in bioink formulation.

bioengineering↗

bioRxiv2023

Nanotopography boosts cellular uptake by inducing macropinocytosis

Efficient cellular uptake of biomolecules, including genetic material, mRNA, proteins, and nanoparticles, requires novel approaches to overcome inherent cellular barriers. This study investigates how nanotopographical cues from nanoporous surfaces impact the uptake efficiency of diverse molecules by cells. The results demonstrate that cellular uptake efficiency increases significantly on nanoporous surfaces compared to flat surfaces. Notably, this process is found to be dependent on the size and morphology of the nanopores, reaching its peak efficacy with blind pores of 400 nm in size. Enhanced genetic transduction on nanoporous surfaces were observed for multiple vectors, including lentiviruses, baculoviruses, and mRNA molecules. The versatile nature of this approach allows co-transfection of cells with multiple mRNA vectors. Moreover, the nanoporous platform was used for efficient and fast manufacturing of CAR-T cells through lentiviral transduction. Furthermore, we pinpoint macropinocytosis as the predominant mechanism driving increased cellular uptake induced by the nanoporous surfaces. The method introduced here for enhancing genetic transduction of cells has applications in immunotherapy research, drug delivery, and cell engineering.

biophysics↗

bioRxiv2020

Signaling mechanism of phytochromes in solution

Phytochrome proteins guide the red/far-red photoresponse of plants, fungi, and bacteria. The proteins change their structure in response to light, thereby altering their biochemical activity. Crystal structures suggest that the mechanism of signal transduction from the chromophore to the output domains involves refolding of the so-called PHY tongue. It is currently not clear how the two other notable structural features of the phytochrome superfamily, the helical spine and a figure-of-eight knot, are involved in photoconversion. Here, we present solution NMR data of the complete photosensory core module from D. radiodurans (Dr BphP). Photoswitching between the resting and active states induces changes in amide chemical shifts, residual dipolar couplings, and relaxation dynamics. All observables indicate a photoinduced structural change in the knot region and lower part of the helical spine. This implies that a conformational signal is transduced from the chromophore to the helical spine through the PAS and GAF domains. The new pathway underpins functional studies of plant phytochromes and may explain photo-sensing by phytochromes under biological conditions.

biochemistry↗