Biology subjects

Dobler, R.

Publications and source records attributed to Dobler, R..

3 recordsLinked to original sources

bioRxiv2025

Functionally distinct ALK and ROS1 fusions detected in infant-type hemispheric gliomas converge on STAT3 and SHP2 activation

ALK and ROS1 fusions are emerging as key drivers of infant-type hemispheric gliomas (IHG). With diverse gene partners, the impact of ALK and ROS1 oncoprotein heterogeneity on glioma biology remains unknown. We developed an integrative phospho-proteomic and transcriptomic approach to discover biological functions regulated by five IHG-associated fusions: CCDC88A::ALK, PPP1CB::ALK, GOPC::ROS1, CLIP1::ROS1 and KIF21A::ROS1. Here, we report fusion-specific oncogenic functions conferred by the 5 gene partner, including increased cell motility driven by microtubule-interacting fusions CCDC88A::ALK and CLIP1::ROS1. All studied fusions converged on a non-canonical STAT3 activation. Using affinity purification mass spectrometry, we identify SHP2 in direct interaction with all three ROS1 oncoproteins, but with none of the ALK oncoproteins, which in turn interact with SHC1/SHC3. ROS1 fusions phosphorylated SHP2 to a larger extent than ALK fusions, and analyses of downstream pathways suggested MAPK-independent, non-canonical SHP2-driven functions. Our findings reveal both common and fusion-specific dependencies, offering opportunities to optimize therapeutic strategies for pediatric gliomas.

cancer biology↗

bioRxiv2024

Testing for age- and sex- specific mitonuclear epistasis in Drosophila

The need for efficient ATP production is predicted to result in the evolution of cooperation between the mitochondrial and nuclear encoded components of the electron transport system. Novel (i.e., mismatched) mitonuclear genotype combinations are therefore predicted to result in negative fitness consequences, which may become more prevalent with ageing. Such negative fitness effects are expected to be prominent in males, since maternal inheritance of mitochondria is predicted to lead to accumulation of male-harming mutations (the mothers curse hypothesis). To test these predictions, we measured female and male fertility traits using a genetically diverse panel of 27 mitonuclear populations of Drosophila melanogaster with matched or experimentally mismatched mitonuclear genomes at different ages. We found no overall effect of mitonuclear mismatch. In females, we found no effect of mitonuclear epistasis. In males, we found limited evidence of mitonuclear epistasis affecting fitness in old age, however, not in the direction predicted. Experimentally mismatched males sired more offspring in one comparison. Sex-specific advantages of mismatched males might arise if novel nuclear alleles compensate for deleterious mitochondrial alleles that have accumulated. If such compensatory effects of novel mitonuclear combinations increasing fitness occur in nature, they could represent a possible counterforce to the mothers curse.

evolutionary biology↗

bioRxiv2019

Interactions between cytoplasmic and nuclear genomes confer sex-specific effects on lifespan in Drosophila melanogaster

A large body of studies has demonstrated that genetic variation that resides outside of the cell nucleus can affect the organismal phenotype. The cytoplasm is home to the mitochondrial genome and, at least in arthropods, often hosts intracellular endosymbiotic bacteria such as Wolbachia. While numerous studies have implicated epistatic interactions between cytoplasmic and nuclear genetic variation as key to mediating patterns of phenotypic expression, two outstanding questions remain. Firstly, the relative contribution of mitochondrial genetic variation to other cytoplasmic sources of variation in shaping the phenotypic outcomes of cyto-nuclear interactions remains unknown. Secondly, it remains unclear whether the outcomes of cyto-nuclear interactions will manifest differently across the two sexes, as might be predicted given that cytoplasmic genomes are screened by natural selection only through females as a consequence of their maternal inheritance. Here, we address these questions, creating a fully-crossed set of replicated cyto-nuclear populations derived from three geographically distinct populations of Drosophila melanogaster, and measuring the lifespan of males and females from each population. We report cyto-nuclear interactions for lifespan, with the outcomes of these interactions differing across the sexes, and reconcile these findings with information on the full mitochondrial sequences and Wolbachia infection status of each of the populations.

evolutionary biology↗