Biology subjects

Morgan, M. J.

Publications and source records attributed to Morgan, M. J..

4 recordsLinked to original sources

bioRxiv2025

Microbiome enrichment from a wild relative improves Black Soldier Fly larval survival, pathogen suppression and growth

Captive rearing can disrupt animal microbiomes, reducing diversity and impairing host performance. For the larvae of Black Soldier Flies (Hermetia illucens; BSFL), a key species in waste bioconversion, microbiome engineering offers a strategy to enhance growth and disease resistance. We tested whether enriching the BSFL microbiome with microbes from a wild relative, Exaireta spinigera, improves larval performance. Axenic BSFL neonates were inoculated with (1) a captive BSFL microbiome, (2) an E. spinigera microbiome, (3) a mixed inoculum of the two, (4) an environmental, diet derived microbiome, or (5) remained axenic. After two weeks, larvae receiving E. spinigera microbes (alone or mixed) exhibited significantly higher growth and survival compared to those inoculated with the captive microbiome. Full-length 16S rRNA gene sequencing revealed successful establishment of diverse taxa from E. spinigera, including Dysgonomonas, Wohlfahrtiimonas, and Scrofimicrobium, some showing strong association with either the larval gut or frass. Notably, enrichment with the E. spinigera microbiome suppressed a pathogenic Pseudomonas aeruginosa strain that dominated the captive microbiome and reduced larval survival in mono-inoculation trials. These findings demonstrate that microbiome enrichment from wild relatives can enhance BSFL health and resilience, supporting a top-down approach to probiotic development for industrial insect rearing. ImportanceBlack Soldier Fly (Hermetia illucens) larvae are increasingly farmed to convert organic waste into valuable products like animal feed and fertilizer. Microbiome composition influences larval health and growth, but captive rearing may restrict or alter functional microbial diversity. Our study shows that enriching the microbiome of captive Black Soldier Flies with microbial diversity of a wild relative species (Exaireta spinigera) improves larval growth while suppressing a pathogenic bacterium. This work demonstrates, for the first time, the potential for utilizing the diversity of microorganisms associated with the over 3000 global species of soldier flies as a source of beneficial probiotics supporting industrial Black Soldier Fly rearing.

microbiology↗

bioRxiv2025

Summing the parts: Improving population estimates using a state-space multispecies production model

Carrying capacity is a fundamental concept in ecology that has inspired the development and application of a broad range of population models. In the context of fisheries science, production models have been employed globally to calculate carrying capacity and guide the sustainable use of fish populations. Production models have, however, been criticized for failing to account for species interactions and environmental effects. We aim to fill some of these gaps by introducing a novel state-space multispecies production model. We apply our extended model to commercially important demersal fish species off the east coast of Canada to assess its ability to reveal species interactions and the relative impacts of fishing and environmental effects. Our results indicate that accounting for species interactions increases the accuracy of biomass estimates for species within a community. The model also revealed strongly correlated process deviations, unrelated to fishing or density-dependent effects, which unexpectidly indicates that widespread collapses were primarily driven by a common environmental driver rather than fishing. Such inferences indicate that this may be a promising avenue for producing more holistic and accurate assessments for multiple species with relatively minimal data requirements (time-series of landings and fisheries-independent indices). Finally, this approach may serve as a stepping stone towards an ecosystem-based approach to fisheries management.

ecology↗

bioRxiv2020

Serial integration of sensory evidence for perceptual decisions and oculomotor responses

Perceptual decisions often require the integration of noisy sensory evidence over time. This process is formalized with sequential sampling models, where evidence is accumulated up to a decision threshold before a choice is made. Although intuition suggests that decision formation must precede the preparation of a motor response (i.e., the action used to communicate the choice), neurophysiological findings have suggested that these two processes might be one and the same. To test this idea, we developed a reverse-correlation protocol in which the visual stimuli that influence decisions can be distinguished from those guiding motor responses. In three experiments, we found that the temporal weighting function of oculomotor responses did not overlap with the relatively early weighting function of stimulus properties having an impact on decision formation. These results support a timeline in which perceptual decisions are formed, at least in part, prior to the preparation of a motor response.

neuroscience↗

bioRxiv2020

A comparative 'omics approach to candidate pathogenicity factor discovery in the brain-eating amoeba Naegleria fowleri

Of the 40 described Naegleria species, only N. fowleri can establish infection in humans, killing almost invariably within two weeks. In the brain, the amoeba performs piece-meal ingestion, or trogocytosis, of brain material causing massive inflammation. Conversely, its close relative Naegleria gruberi, which is used as a laboratory model organism, is non-pathogenic. The exact pathogenicity factors distinguishing N. fowleri from its harmless relatives are unclear. We have here taken an -omics approach to understanding N. fowleri biology and infection at the system level. We provide the first analysis of genomic diversity between strains, finding little conservation in synteny but high conservation in protein complement. We also demonstrate that the N. fowleri genome encodes a similarly complete cellular repertoire to that found in N. gruberi. Our comparative genomic analysis, together with a transcriptomic analysis of low versus high pathogenicity N. fowleri cultured in a mouse infection model, allowed us to construct a model of cellular systems involved in pathogenicity and furthermore provides ~500 novel candidate pathogenicity factors in this currently rare but highly fatal pathogen.

microbiology↗