Biology subjects

Alten, B.

Publications and source records attributed to Alten, B..

3 recordsLinked to original sources

bioRxiv2025

Ancient origin of an urban underground mosquito

Understanding how life is adapting to urban environments represents an important challenge in evolutionary biology. Here we investigate a widely cited example of urban adaptation, Culex pipiens form molestus, also known as the London Underground Mosquito. Population genomic analysis of [~]350 contemporary and historical samples counter the popular hypothesis that molestus originated belowground in London less than 200 years ago. Instead, we show that molestus first adapted to human environments aboveground in the Middle East over the course of >1000 years, likely in concert with the rise of agricultural civilizations. Our results highlight the role of early human society in priming taxa for contemporary urban evolution and have important implications for understanding arbovirus transmission.

evolutionary biology↗

bioRxiv2023

Cryo-electron tomography reveals postsynaptic nanoblocks in excitatory synapses for transcellular alignment

The nanoscale organization of proteins within synapses is critical for maintaining and regulating synaptic transmission and plasticity. Here, we use cryogenic electron tomography to directly visualize the three-dimensional architecture and supramolecular organization of pre-cleft-postsynaptic components in their near-native cellular context in both synaptosomes from rat hippocampi and synapses from rat primary cultured neurons. High-resolution electron microscopy and quantitative analyses revealed that postsynaptic density (PSD) is composed of membrane-associated nanoblocks of various sizes, which are in close relationship with potential presynaptic release sites through adhesion molecules spanning the synaptic cleft, as well as with post-synaptic receptors. Subtomogram averaging from synaptosomes showed two distinct types of postsynaptic membrane proteins at resolutions of 24 [A] and 26 [A] respectively. Furthermore, our data reveal that majority of potential release sites and [~]50% subtomogram averaged receptor-like particles are located within the boundary of PSD nanoblocks, while PSD nanoblocks might be redundant for neurotransmission. The results of this study provide a more comprehensive understanding of synaptic ultrastructure and suggest that PSD is composed of clustering of various nanoblocks, which likely underlies the dynamic nature of PSD to modulate synaptic strength.

neuroscience↗

bioRxiv2020

Model-based design and analysis of life table experiments for insect vectors

Life tables help identify physiological differences in distinct development stages and detect potential vulnerabilities for conservation and control. However, cataloguing mortality, development, and fecundity by following each individual could be challenging in insects due to interweaving generations and development stages.Here, we propose to use age- and stage-structured population dynamics modelling to help derive life table characteristics from the observed dynamics of reared populations. We examine a hypothetical case, a simulated population with known life parameters, and two experimental cases, observations of the population dynamics of the mosquito vectors Culex quinquefasciatus and Culex pipiens, to demonstrate that model-based inference can correctly identify life parameters from longitudinal observations. The analysis reveals not only the differential physiological behaviour of distinct development stages, but also identifies the degree to which each parameter can be inferred from the data.The methods introduced constitute a model-based approach to identifying life table characteristics from incomplete longitudinal data, and help to improve the design of life table experiments. The approach is readily applicable to the development of climate- and environment-driven population dynamics models for important vectors of disease.Competing Interest StatementThe authors have declared no competing interest.View Full Text

ecology↗