Biology subjects

Henning, R.

Publications and source records attributed to Henning, R..

4 recordsLinked to original sources

bioRxiv2026

Socially transmitted knowledge of hibernation sites in bats

In temperate regions around the world, bats travel long distances every winter to gather at hibernation sites. A longstanding hypothesis is that each new generation of bats learns about the locations of these sites (called hibernacula) from older individuals, yet clear and compelling evidence demonstrating social transmission of this knowledge has been lacking. Here, we compiled 30,882 observations from 1985 to 2023 of 13,852 Greater mouse-eared bats (Myotis myotis) that were banded and observed at summer roosts, winter hibernacula, or both. Our analyses revealed four lines of evidence that Greater mouse-eared bats find suitable hibernacula using social information acquired at summer roosts. First, naive yearlings were more likely to be seen sharing their first hibernacula with adults from their summer birth colony relative to a null model where bats moved independently. Second, adult bats were also more likely to co-switch together into the same hibernacula across winters than expected from independent movements. Third, bats that roosted together in the summer were more likely to share a different site as a hibernaculum during the winter: being observed together during a summer changed the probability of a pair being observed together during a winter from 5% to 12%. Finally, high-resolution tracking revealed an instance of tandem flights to hibernacula sites during the summer, demonstrating that yearlings can learn from experienced adult bats months before hibernation. Together, our findings show that maternity colonies serve as "information centers" where females acquire knowledge of suitable hibernation sites throughout their long lives.

animal behavior and cognition↗

bioRxiv2026

Calorie Restriction-Induced Daily Hibernation in Mice Drives Cyclic DNA Damage and Repair

Hibernation consists of bouts of torpor, characterized by profound decreases in metabolism and body temperature (Tb), alternated with periods of euthermia called interbout arousals, during which normal metabolism and Tb resume. Seasonal hibernators accumulate DNA strand breaks during torpor, which are repaired during arousal. Here, we assess dynamics of DNA damage and repair during serial daily torpor in mice induced by 30% calorie restriction (CR) and investigate the effects of metabolic challenge on DNA repair. Serial daily torpor induced by CR in C57/BL6J mice of both sexes housed at 20{degrees}C lasts 6-12 hours. Like seasonal hibernators, DNA damage increases in CR-induced torpor and is repaired in the subsequent euthermic period, as evidenced by comet assay and {gamma}H2AX accumulation. To metabolically challenge animals, ambient temperature (Ta) was lowered to 4{degrees}C, since torpid mice defend a Tb of around 20{degrees}C or higher. Despite inducing a significant metabolic challenge, housing of torpid mice at 4{degrees}C does not increase DNA damage compared to 20{degrees}C housing. However, reducing Ta to 4{degrees}C during euthermia inhibits DNA repair. Interestingly, p21 levels increase in mice exposed to 4{degrees}C, indicating cell-cycle inhibition during exposure to 4{degrees}C. Thus, 30% CR induces daily cycles of torpor-induced DNA damage and euthermia-associated DNA repair in mice, and exposure to a Ta of 4{degrees}C during arousal inhibits DNA repair mounting a cell cycle inhibition response. Thus, the torpor-arousal cycle may be a contributing factor to the lifespan extension benefits of CR in mice, promoting genomic integrity and thereby cellular and tissue health.

physiology↗

bioRxiv2024

Resolving DJ-1 Glyoxalase Catalysis Using Mix-and-Inject Serial Crystallography at a Synchrotron

DJ-1 (PARK7) is an intensively studied protein whose cytoprotective activities are dysregulated in multiple diseases. DJ-1 has been reported as having two distinct enzymatic activities in defense against reactive carbonyl species that are difficult to distinguish in conventional biochemical experiments. Here, we establish the mechanism of DJ-1 using a synchrotron-compatible version of mix-and-inject-serial crystallography (MISC), which was previously performed only at XFELs, to directly observe DJ-1 catalysis. We designed and used new diffusive mixers to collect time-resolved Laue diffraction data of DJ-1 catalysis at a pink beam synchrotron beamline. Analysis of structurally similar methylglyoxal-derived intermediates formed through the DJ-1 catalytic cycle shows that the enzyme catalyzes nearly two turnovers in the crystal and defines key aspects of its glyoxalase mechanism. In addition, DJ-1 shows allosteric communication between a distal site at the dimer interface and the active site that changes during catalysis. Our results rule out the widely cited deglycase mechanism for DJ-1 action and provide an explanation for how DJ-1 produces L-lactate with high chiral purity.

biochemistry↗

bioRxiv2020

Glycosyltransferase POMGNT1 deficiency affects N-cadherin-mediated cell-cell adhesion

Defects in protein O-mannosylation lead to severe congenital muscular dystrophies known as -dystroglycanopathy. A hallmark of these diseases is the loss of the O-mannose-bound matriglycan on -dystroglycan, which leads to a reduction in cell adhesion to the extracellular matrix. Mutations in protein O-mannose {beta}1,2-N-acetylglucosaminyltransferase 1 (POMGNT1), which is crucial for the elongation of O-mannosyl glycans, are mainly associated with muscle-eye-brain (MEB) disease. In addition to defects in cell-extracellular matrix adhesion, aberrant cell-cell adhesion has occasionally been observed in response to defects in POMGNT1. However, direct molecular mechanisms are largely unknown. We used POMGNT1 knock-out HEK293T cells and fibroblasts from a MEB patient to gain a deeper insight into the molecular changes in POMGNT1 deficiency. A combination of biochemical and molecular biological techniques with proteomics, glycoproteomics and glycomics revealed that a lack of POMGNT1 activity strengthens cell-cell adhesion. We demonstrate that the altered intrinsic adhesion properties are due to an increased abundance of N-cadherin (N-Cdh). In addition, site-specific changes in the N-glycan structures in the extracellular domain of N-Cdh were detected, which positively impact on homotypic interactions. We found that in POMGNT1 deficient cells ERK1/2 and p38 signaling pathways are activated and transcriptional changes that are comparable to the epithelial-mesenchymal transition (EMT) are triggered, defining a possible molecular mechanism underlying the observed phenotype. Our study indicates that changes in cadherin-mediated cell-cell adhesion and other EMT-related processes may contribute to the complex clinical symptoms of MEB or -dystroglycanopathy in general, and suggests a previously underestimated impact of changes in O-mannosylation on N-glycosylation.

biochemistry↗