Biology subjects

Conway, M.

Publications and source records attributed to Conway, M..

3 recordsLinked to original sources

bioRxiv2025

An axon-intrinsic loop restricts nerve regeneration through axonal protein synthesis

Injured axons synthesize the RNA Binding Protein KHSRP that promotes mRNA decay and slows nerve regeneration. Axotomy-induced increase in axoplasmic Ca2+ activates axonal Khsrp translation, and while Ca2+ returns to pre-injury levels within 16 hours post-axotomy, axonal KHSRP remains elevated. Alternating translation of Reg3a and Khsrp sustains axonal KHSRP levels in regenerating axons. Nerve injury activates Reg3a expression, resulting in increased REG3A synthesis and secretion from axons. REG3A stimulates ER Ca2+ release to activate PERK, increase eIF2 phosphorylation, and increase Khsrp translation. Axoplasmic Ca2+ slowly oscillates in growth cones and Reg3A depletion attenuates growth cone Ca2+ oscillations, decreases KHSRP synthesis, reduces the axons retractive events, and accelerates peripheral nerve regeneration. Thus, REG3A to KHSRP signaling provides an axon-intrinsic loop that decelerates axon growth through localized mRNA translation.

neuroscience↗

bioRxiv2023

Multiple axes of visual system diversity in Ithomiini, an ecologically diverse tribe of mimetic butterflies

The striking structural variation seen in arthropod visual systems can be explained by the overall quantity and spatio-temporal structure of light within habitats coupled with developmental and physiological constraints. However, little is currently known about how fine-scale variation in visual structures arise across shorter evolutionary and ecological scales. In this study, we characterise patterns of interspecific (between species), intraspecific (between sexes) and intraindividual (between eye regions) variation in the visual system of four ithomiine butterfly species. These species are part of a diverse 26-Myr-old Neotropical radiation where changes in mimetic colouration are associated with fine-scale shifts in ecology, such as microhabitat preference. By using a combination of selection analyses on visual opsin sequences, in-vivo ophthalmoscopy, micro-computed tomography (micro-CT), immunohistochemistry, confocal microscopy, and neural tracing, we quantify and describe physiological, anatomical, and molecular traits involved in visual processing. Using these data, we provide evidence of substantial variation within the visual systems of Ithomiini, including: i) relaxed selection on visual opsins, perhaps mediated by habitat preference, ii) interspecific shifts in visual system physiology and anatomy, and iii) extensive sexual dimorphism, including the complete absence of a butterfly-specific optic neuropil in the males of some species. We conclude that considerable visual system variation can exist within diverse insect radiations, hinting at the evolutionary lability of these systems to rapidly develop specialisations to distinct visual ecologies, with selection acting at both the perceptual, processing, and molecular level. Summary statementPhysiological, anatomical, and molecular evidence of extensive visual system variation within a diverse butterfly radiation, hinting at the lability of visual systems to evolve specialisations to distinct visual environments.

evolutionary biology↗

bioRxiv2020

Outdoor Atmospheric Microbial Diversity is Associated with Three-Dimensional Urban Landscape Structure and Differs from Indoor-Transit Systems

Microbes are abundant inhabitants of the near-surface atmosphere in urban areas. The distribution of microbial communities may benefit or hinder human wellbeing and ecosystem function. Surveys of airborne microbial diversity are uncommon in both natural and built environments and those that investigate diversity are stationary in the city, thus missing continuous exposure to microbes that covary with three-dimensional urban structure. Individuals in cities are generally mobile and would be exposed to diverse urban structures outdoors and within indoor-transit systems in a day. We used mobile monitoring of microbial diversity and geographic information system spatial analysis, across Philadelphia, Pennsylvania, USA in outdoor and indoor-transit (subways and train cars) environments. This study identifies to the role of the three-dimensional urban landscape in structuring atmospheric microbiomes and employs mobile monitoring over ~1920 kilometers to measure continuous biodiversity. We found more diverse communities outdoors that significantly differ from indoor-transit air in microbial community structure, function, likely source environment, and potentially pathogenic fraction of the community. Variation in the structure of the urban landscape was associated with diversity and function of the near-surface atmospheric microbiome in outdoor samples. ImportanceGlobal nutrient cycling and human health depend on the rich biodiversity of microorganisms. The influence of the urban environment on microbiomes remains poorly described despite cities being the fastest growing ecosystems. All life is exposed to the atmosphere and thus discerning what microbes are present and what their functions may be is critical to create resistant and resilient cities under climate change. This study combines a spatially explicit analysis of urban structure with mobile monitoring of the atmospheric microbiome.

ecology↗