Biology subjects

Klose, M.

Publications and source records attributed to Klose, M..

4 recordsLinked to original sources

bioRxiv2026

Combining evolution and machine learning-guided pathway optimization to engineer a novel methylsuccinate module for synthetic C1 metabolism in vivo

De novo metabolic pathways open possibilities for sustainable biotransformations in microbes. However, the in vivo-implementation of such new-to-nature pathways is highly challenging and heavily relies on adaptive laboratory evolution (ALE) of the hosts native metabolic network. Here, we assess how much this need for host-centric ALE can be overcome and/or complemented through the informed design of the newly introduced pathway. Exemplifying for a synthetic CO2-fixation module via methyl-succinate, we established methylsuccinate-dependent growth of Escherichia coli over six months by ALE of E. colis native metabolism. In parallel, we developed a machine-learning guided workflow (MEVIS) for the automated engineering of the synthetic pathway, resulting in methylsuccinate-dependent growth within three weeks. Critically, performing MEVIS in the background of the ALE-evolved strain is necessary to further approach wild-type like growth, demonstrating how ALE in combination with machine-learning-guided lab automation holds great potential to accelerate and improve design-build-test-learn cycles in contemporary metabolic engineering.

bioengineering↗

bioRxiv2024

Advancing chloroplast synthetic biology through high-throughput plastome engineering of Chlamydomonas reinhardtii

Chloroplast synthetic biology holds promise for developing improved crops through improving the function of plastids. However, chloroplast engineering efforts face limitations due to the scarcity of genetic tools and the low throughput of plant-based systems. To address these challenges, we here established Chlamydomonas reinhardtii as a prototyping chassis for chloroplast synthetic biology. We developed an automation workflow that enables the generation, handling, and analysis of thousands of transplastomic strains in parallel, expanded the repertoire of selection markers for chloroplast transformation, established new reporter genes, and characterized over 140 regulatory parts, including native and synthetic promoters, UTRs, and intercistronic expression elements. We integrated the system within the Phytobrick cloning standard and demonstrate several applications, including a library-based approach to develop synthetic promoter designs in plastids. Finally, we provide a proof-of-concept for prototyping novel traits in plastids by introducing a chloroplast-based synthetic photorespiration pathway and demonstrating a twofold increase in biomass production. Overall, our study advances chloroplast engineering, and provides a promising platform to rapidly prototype chloroplast manipulations before their transfer into higher plants and crops.

synthetic biology↗

bioRxiv2020

Mathematical modelling of megakaryopoiesis in Mpl-deficient and continuously thrombopoietin-stimulated mice points to an unknown control mechanism

Thrombopoietin (TPO) is the ligand of the Mpl receptor and the key regulator of megakaryopoiesis and platelet production. A loss or gain of the TPO-receptor function affects haematopoiesis and results in severe diseases in humans. Appropriate mouse strains are available to mimic both myeloproliferative neoplasm (MPN) and congenital amegakaryocytic thrombocytopenia (CAMT) resulting from TPO overexpression or knockout of TPO receptor Mpl on megakaryocytes and platelets, respectively. However, at a quantitative level it is not understood, how the known regulations can establish the impaired but stable disease phenotypes. Starting out from an established mathematical model for megakaryopoiesis, we aim to adapt it to both the healthy situation and to distinct diseased phenotypes mimicking MPN. We thereby identify, that some of the model parameters are invariant with respect to the mouse strain while others have to be estimated in a strain-dependent manner. A systematic process of parameter identification provides strong evidence that the well-known excess production of megakaryocytes and early progenitors in MPN is either directly contingent on Mpl expression of platelets and megakaryocytes or, alternatively, that the knockout of Mpl is not as precisely restricted to megakaryocytes and platelets but may also effect their progenitors. In conclusion, our analysis hints towards an opaque control mechanism rendering megakaryopoiesis at a yet unknown level, and awaiting further experimental evaluation.

systems biology↗

bioRxiv2018

Hematopoietic Stem Cell Dynamics are Regulated by Progenitor Demand: Lessons from a Quantitative Modeling Approach

The prevailing view on murine hematopoiesis and on hematopoietic stem cells (HSC) in particular derives from experiments that are related to regeneration after irradiation and HSC transplantation. However, over the past years, different experimental techniques have been developed to investigate hematopoiesis under homeostatic conditions, thereby providing access to proliferation and differentiation rates of hematopoietic stem and progenitor cells in the unperturbed situation. Moreover, it has become clear that hematopoiesis undergoes distinct changes during aging with large effects on HSC abundance, lineage contribution, asymmetry of division and self-renewal potential. However, it is currently not fully resolved how stem and progenitor cells interact to respond to varying demands and how this balance is altered by an aging-induced shift in HSC polarity.\n\nHere, we present an in-silico model to investigate the dynamics of HSC response to varying demand. By introducing an internal feedback between stem and progenitor cells, the model is suited to consistently describe both hematopoietic homeostasis and regeneration, including the limited regulation of HSCs in the homeostatic situation. The model further explains the age-dependent increase in phenotypic HSCs as a consequence of the cells inability to preserve divisional asymmetry.\n\nOur model suggests a dynamically regulated population of intrinsically asymmetrically dividing HSCs as suitable control mechanism that adheres with many qualitative and quantitative findings on hematopoietic recovery after stress and aging. The modeling approach thereby illustrates how a mathematical formalism can support the conceptual and the quantitative understanding of regulatory principles in HSC biology.

systems biology↗