Biology subjects

Hein, B.

Publications and source records attributed to Hein, B..

4 recordsLinked to original sources

bioRxiv2026

Phylogenomic Characterization of Two Alternaria Lineages Associated with Cotton Leaf Spot in Tennessee

Alternaria leaf spot is an important foliar disease of cotton (Gossypium hirsutum L.) and has historically been associated primarily with Alternaria macrospora in the United States. In November 2025, symptomatic Upland cotton leaves from a research greenhouse at Tennessee Technological University's Oakley Farm in Livingston, Tennessee, yielded two Alternaria isolates, 2-2 and 9-1. Quantitative conidial characterization showed substantial overlap in dimensions, septation, and shape. Concatenated ITS-RPB2 phylogenetic analysis supported different broad affinities, placing isolate 2-2 within an A. alternata- dominated group and isolate 9-1 within a group associated with the A. arborescens species complex (AASC), although their immediate relationships were weakly resolved. Phylogenomic analysis of 1,501 single-copy BUSCO orthologs from 63 genomes placed isolate 2-2 within the A. alternata lineage, sister to BMP2343, and isolate 9-1 within the AASC, sister to MOD1-FUNGI6. In controlled pathogenicity assays, isolate 9-1 reproduced foliar lesions on cotton, whereas mock-inoculated plants remained symptomless, and molecularly confirmed re-isolation fulfilled Koch's postulates. Isolate 2-2 produced insufficient conidia under the culture conditions used to prepare a standardized inoculum, and its pathogenicity was therefore not determined. These results reveal phylogenetically distinct Alternaria lineages associated with symptomatic cotton and establish an AASC isolate as a causal agent of cotton leaf spot in Tennessee.

pathology↗

bioRxiv2024

Developmental maturation of millimeter-scale functional networks across brain areas

Interacting with the environment to process sensory information, generate perceptions, and shape behavior engages neural networks in brain areas with highly varied representations, ranging from unimodal sensory cortices to higher-order association areas. Recent work suggests a much greater degree of commonality across areas, with distributed and modular networks present in both sensory and non-sensory areas during early development. However, it is currently unknown whether this initially common modular structure undergoes an equally common developmental trajectory, or whether such a modular functional organization persists in some areas--such as primary visual cortex--but not others. Here we examine the development of network organization across diverse cortical regions in ferrets of both sexes using in vivo widefield calcium imaging of spontaneous activity. We find that all regions examined, including both primary sensory cortices (visual, auditory, and somatosensory--V1, A1, and S1, respectively) and higher order association areas (prefrontal and posterior parietal cortices) exhibit a largely similar pattern of changes over an approximately 3 week developmental period spanning eye opening and the transition to predominantly externally-driven sensory activity. We find that both a modular functional organization and millimeter-scale correlated networks remain present across all cortical areas examined. These networks weakened over development in most cortical areas, but strengthened in V1. Overall, the conserved maintenance of modular organization across different cortical areas suggests a common pathway of network refinement, and suggests that a modular organization--known to encode functional representations in visual areas--may be similarly engaged in highly diverse brain areas. SignificanceDifferent areas of the mature brain encode vastly different representations of the world. This study shows that a modular functional organization where nearby neurons participate in similar functional networks is shared across different brain areas not only during early development, but also as the brain matures where it remains a shared feature that shapes neural activity. The largely conserved trajectory of developmental changes across brain areas suggests that similar circuit mechanisms may drive this maturation. This implies that the large literature on developing cortical circuits, which is largely focused on sensory areas, may also apply more broadly, and that perturbations during development that impinge on any such shared mechanisms may produce deficits that extend across multiple brain systems.

neuroscience↗

bioRxiv2021

Tightly-coupled inhibitory and excitatory functional networks in the early visual cortex

Intracortical inhibition plays a critical role in shaping activity patterns in the mature cortex. However, little is known about the structure of inhibition in early development prior to the onset of sensory experience, a time when spontaneous activity exhibits long-range correlations predictive of mature functional networks. Here, using calcium imaging of GABAergic neurons in the early ferret visual cortex, we show that spontaneous activity in inhibitory neurons is already highly organized into distributed modular networks before visual experience. Inhibitory neurons exhibit spatially modular activity with long-range correlations and precise local organization that is in quantitative agreement with excitatory networks. Furthermore, excitatory and inhibitory networks are strongly co-aligned at both millimeter and cellular scales. These results demonstrate a remarkable degree of organization in inhibitory networks early in the developing cortex, providing support for computational models of self-organizing networks and suggesting a mechanism for the emergence of distributed functional networks during development.

neuroscience↗

bioRxiv2018

Long-range order from local interactions: organization and development of distributed corticalnetworks

The cortical networks that underlie behavior exhibit an orderly functional organization at local and global scales, which is readily evident in the visual cortex of carnivores and primates1-6. Here, neighboring columns of neurons represent the full range of stimulus orientations and contribute to distributed networks spanning several millimeters2,7-11. However, the principles governing functional interactions that bridge this fine-scale functional architecture and distant network elements are unclear, and the emergence of these network interactions during development remains unexplored. Here, by using in vivo wide-field and 2-photon calcium imaging of spontaneous activity patterns in mature ferret visual cortex, we find widespread and specific modular correlation patterns that accurately predict the local structure of visually-evoked orientation columns from the spontaneous activity of neurons that lie several millimeters away. The large-scale networks revealed by correlated spontaneous activity show abrupt fractures in continuity that are in tight register with evoked orientation pinwheels. Chronic in vivo imaging demonstrates that these large-scale modular correlation patterns and fractures are already present at early stages of cortical development and predictive of the mature network structure. Silencing feed-forward drive through either retinal or thalamic blockade does not affect network structure suggesting a cortical origin for this large-scale correlated activity, despite the immaturity of long-range horizontal network connections in the early cortex. Using a circuit model containing only local connections, we demonstrate that such a circuit is sufficient to generate large-scale correlated activity, while also producing correlated networks showing strong fractures, a reduced dimensionality, and an elongated local correlation structure, all in close agreement with our empirical data. These results demonstrate the precise local and global organization of cortical networks revealed through correlated spontaneous activity and suggest that local connections in early cortical circuits may generate structured long-range network correlations that underlie the subsequent formation of visually-evoked distributed functional networks.

neuroscience↗