Biology subjects

Winkler, L.

Publications and source records attributed to Winkler, L..

7 recordsLinked to original sources

bioRxiv2025

Assessing the diversity and functional profile of the microbial proteome in fermented foods

Fermented foods are staples in diets worldwide and are known for their health benefits. Microorganisms are the key to fermented food production as they convert raw substrates into digestible, nutritious, and health-promoting products. While microbes are essential for fermented food production, their contribution to the dietary protein profile of the final food product in terms of microbial biomass is largely unknown. We analyzed proteins from 17 fermented foods using metaproteomics to identify and quantify microbial and food-derived proteins. We found that microbial proteins contribute up to 11% of the total protein content in fermented foods and comprise as much as 60% of the total number of identified proteins. These microbial proteins included many for central functions in microbial cells, such as glycolysis enzymes, translation machinery, and chaperones, as well as proteins for specialized functions that are important for the ecological niches in food fermentation, such as carbohydrate degrading enzymes and proteases. Some of these microbial proteins, such as proteases, could impact gut physiology. These findings highlight the substantial contribution of microbial proteins to the nutritional and functional profile of fermented foods, which may have important implications for interactions with the gut microbiota and health outcomes.

microbiology↗

bioRxiv2024

Beta Waves in Action: Context-Dependent Modulations of Subthalamo-Cortical Synchronization during Rapid Reversals of Movement Direction

The role of beta band activity in cortico-basal ganglia interactions during motor control has been studied extensively in resting-state and for simple movements, such as button pressing. However, little is known about how beta oscillations change and interact in more complex situations involving rapid changes of movement in various contexts. To close this knowledge gap, we combined magnetoencephalography (MEG) and local field potential recordings from the subthalamic nucleus (STN) in Parkinsons disease patients to study beta dynamics during initiation, stopping, and rapid reversal of rotational movements. The action prompts were manipulated to be predictable vs. unpredictable. We observed movement-related beta suppression at motor sequence start, and a beta rebound after motor sequence stop in STN power, motor cortical power, and STN-cortex coherence. Despite involving a brief stop of movement, no clear rebound was observed during reversals of turning direction. On the cortical level, beta power decreased bilaterally following reversals, but more so in the hemisphere ipsilateral to movement, due to a floor effect on the contralateral side. In the STN, power modulations varied across patients, with patients revealing brief increases or decreases of high-beta power. Importantly, cue predictability affected these modulations. Event-related increases of STN-cortex beta coherence were generally stronger in the unpredictable than in the predictable condition. In summary, this study reveals the influence of movement context on beta oscillations in basal ganglia-cortex loops when humans change ongoing movements according to external cues. We find that movement scenarios requiring higher levels of caution involve enhanced modulations of subthalamo-cortical beta synchronization. Further, our results confirm that beta oscillations reflect the start and end of motor sequences better than movement changes within a sequence. Significance StatementBeta synchrony between motor cortex and the subthalamic nucleus is intensified when instructional cues within a continuous motor sequence become less predictable, calling for more cautious behavior.

neuroscience↗

bioRxiv2022

Sexual selection moderates heat stress response in males and females

A widespread effect of climate change is the displacement of organisms from their thermal optima. The associated thermal stress imposed by climate change has been argued to have a particularly strong impact on male reproduction but evidence for this postulated sex-specific stress response is equivocal. One important factor that may explain intra- and interspecific variation in stress responses is sexual selection, which is predicted to magnify negative effects of stress. Nevertheless, empirical studies exploring the interplay of sexual selection and heat stress are still scarce. We tested experimentally for an interaction between sexual selection and thermal stress in the red flour beetle Tribolium castaneum by contrasting heat responses in male and female reproductive success between setups of enforced monogamy versus polygamy. We found that polygamy magnifies detrimental effects of heat stress in males but relaxes the observed negative effects in females. Our results suggest that sexual selection can reverse sex differences in thermal sensitivity, and may therefore alter sex-specific selection on alleles associated with heat tolerance. We argue that these findings have important implications for predicting the role of sexual selection for the adaptation to current global warming and increased frequency of extreme climatic events.

evolutionary biology↗

bioRxiv2021

Sexual selection in females across the animal tree of life

The pioneers of sexual selection theory proposed that males are generally eager whereas females are rather coy with respect to mating. This male-centred perspective on sexual selection continues to permeate our perception of sex differences across disciplines. Despite an increased awareness that females also compete for mating partners, we still tend to consider sexual selection in females a rare peculiarity. Here we present meta-analytic evidence from 72 species across a broad range of animal taxa to show that sexual selection in females is widespread and should be considered the norm rather than the exception. Thereby, our results extend our general understanding of sexual reproduction and may contribute to a more balanced perspective of how sexual selection operates in both males and females.

evolutionary biology↗

bioRxiv2021

Stronger net selection on males across animals

Sexual selection is considered the major driver for the evolution of manifold sex differences. However, the eco-evolutionary dynamics of sexual selection and their role for a populations adaptive potential to respond to environmental change have only recently been explored. Theory predicts that sexual selection promotes adaptation at a low demographic cost only if net selection is stronger on males compared to females. We used a comparative approach to show that net selection is indeed stronger in males in species prone to intense sexual selection. Given that both sexes share the vast majority of their genes, our findings corroborate the notion that the genome is often confronted with a more stressful environment when expressed in males. Collectively, our study supports a long-standing key assumption required for sexual selection to bolster adaptation, and intense sexual selection may therefore enable some species to track environmental change more efficiently. One sentence summaryComparative study finds support for stronger net selection in males.

evolutionary biology↗

bioRxiv2019

Claudin-12 deficiency causes nerve barrier breakdown, mechanical hypersensitivity and painful neuropathy

Peripheral nerves and their axons are shielded by the blood-nerve and the myelin barrier, but understanding of how these barriers impact nociception is limited. Here, we identified a regulatory axis of the tight junction protein claudin-12, sex-dependently controlling perineurial and myelin barrier integrity. In nerve biopsies, claudin-12 in Schwann cells was lost in male and postmenopausal female patients with painful but not painless polyneuropathy. Global Cldn12 gene-knockout selectively increased perineurial/myelin barrier leakage, damaged tight junction protein expression and morphology, increased proinflammatory cytokines and induced mechanical hypersensitivity in naive and neuropathic male mice, respectively. Other barriers and neurological function remained intact. In vitro transfection studies documented claudin-12 plasma membrane localisation without interaction with other tight junction proteins or intrinsic sealing properties. Rather, claudin-12 had a regulatory tight junction protein function on the myelin barrier via the morphogen SHH in vivo in Cldn12-KO and after local siRNA knockdown. Fertile female mice were completely protected. Collectively, these studies reveal the critical role of claudin-12 maintaining the myelin barrier and highlight restoration of the claudin-12/SHH pathway as a potential target for painful neuropathy.

neuroscience↗

bioRxiv2019

Revisiting Feature Selection with Data Complexity for Biomedicine

The identification of biomarkers or predictive features that are indicative of a specific biological or disease state is a major research topic in biomedical applications. Several feature selection(FS) methods ranging from simple univariate methods to recent deep-learning methods have been proposed to select a minimal set of the most predictive features. However, there still lacks the answer to the question of "which method to use when". In this paper, we study the performance of feature selection methods with respect to the underlying datasets statistics and their data complexity measures. We perform a comparative study of 11 feature selection methods over 27 publicly available datasets evaluated over a range of number of selected features using classification as the downstream task. We take the first step towards understanding the FS methods performance from the viewpoint of data complexity. Specifically, we (empirically) show that as regard to classification, the performance of all studied feature selection methods is highly correlated with the error rate of a nearest neighbor based classifier. We also argue about the non-suitability of studied complexity measures to determine the optimal number of relevant features. While looking closely at several other aspects, we also provide recommendations for choosing a particular FS method for a given dataset.

bioinformatics↗