Biology subjects

Kerr, E. N.

Publications and source records attributed to Kerr, E. N..

3 recordsLinked to original sources

bioRxiv2026

Functional redundancy and anaerobic metabolism characterize the skin microbiome of a critically endangered sawfish

Using shotgun metagenomics of largetooth sawfish (Pristis pristis) skin and paired pool water samples, we provide the first taxonomic and functional characterization of a sawfish skin microbiome and assess its ecological distinctiveness, assembly, and resilience relative to the surrounding water column. The skin microbiome was strongly host-associated and compositionally distinct, with lower taxonomic richness than the water column but dominated by Bacillota, particularly spore-forming Bacilli. Functional profiling revealed enrichment of genes associated with sporulation, dormancy, anaerobic metabolism, and peptide transport, consistent with adaptation to low-oxygen, low-flow pool conditions. In contrast, water-column microbiomes were more taxonomically diverse and enriched in phototrophic and polysaccharide-utilization pathways. Despite reduced taxonomic diversity, sawfish skin communities exhibited higher functional redundancy, with gene functions accumulating more rapidly per taxon. This pattern supports a host-filtered, lottery-like assembly process that produces taxonomically variable yet functionally conserved communities. The enrichment of dormancy and anaerobic pathways suggests the skin microbiome persists through periods of host quiescence and environmental stress while maintaining metabolic potential. Together, these results demonstrate that the sawfish skin supports a resilient, functionally robust microbiome distinct from ambient aquatic communities, highlighting the potential for integrating microbial functional data into conservation strategies for Critically Endangered vertebrates.

ecology↗

bioRxiv2024

Elasmobranchs Exhibit Species-Specific Epidermal Microbiomes Guided by Denticle Topography

Elasmobranch epidermal microbiomes are species-specific, yet microbial assembly and retainment drivers are mainly unknown. The contribution of host-derived factors in recruiting an associated microbiome is essential for understanding host-microbe interactions. Here, we focus on the physical aspect of the host skin in structuring microbial communities. Each species of elasmobranch exhibits unique denticle morphology, and we investigate whether microbial communities and functional pathways are correlated with the morphological features or follow the phylogeny of the three species. We extracted and sequenced the DNA from the epidermal microbial communities of three captive shark species: Horn (Heterodontus francisci), Leopard (Triakis semifasciata), and Swell shark (Cephaloscyllium ventriosum) and use electron microscopy to measure the dermal denticle features of each species. Our results outline species-specific microbial communities, as microbiome compositions vary at the phyla level; C. ventriosum hosted a higher relative abundance of Pseudomonadota and Bacillota, while H. francisci were associated with a higher prevalence of Euryarchaeota and Aquificae, and Bacteroidota and Crenarchaeota were ubiquitous with T. semifasciata. Functional pathways performed by each species respective microbiome were species-specific metabolic. Microbial genes associated with aminosugars and electron-accepting reactions were correlated with the distance between dermal denticles, whereas desiccation stress genes were only present when the dermal denticle overlapped. Microbial genes associated with Pyrimidines, chemotaxis and virulence followed the phylogeny of the sharks. Several microbial genera display associations that resemble host evolutionary lineage, while others had linear relationships with interdenticle distance. Therefore, denticle morphology was a selective influence for some microbes and functions in the microbiome contributing to the phylosymbiosis. ImportanceMicrobial communities form species-specific relationships with vertebrate hosts, but the drivers of these relationships remain an outstanding question. We explore the relationship between a physical feature of the host and the microbial community. A distinguishing feature of the subclass Elasmobranchii (sharks, rays, and skates), is the presence of dermal denticles on the skin. These structures protrude through the epidermis providing increased swimming efficiency for the host and an artificial model skin affect microbial recruitment and establishment of cultured microbes but has not been tested on natural microbiomes. Here, we show some naturally occurring microbial genera and functional attributes were correlated with dermal denticle features, suggesting they are one, but not only contributing factor in microbiome structure on benthic sharks.

microbiology↗

bioRxiv2021

Genome-wide association analyses of individual differences in quantitatively assessed reading- and language-related skills in up to 34,000 people

The use of spoken and written language is a capacity that is unique to humans. Individual differences in reading- and language-related skills are influenced by genetic variation, with twin-based heritability estimates of 30-80%, depending on the trait. The relevant genetic architecture is complex, heterogeneous, and multifactorial, and yet to be investigated with well-powered studies. Here, we present a multicohort genome-wide association study (GWAS) of five traits assessed individually using psychometric measures: word reading, nonword reading, spelling, phoneme awareness, and nonword repetition, with total sample sizes ranging from 13,633 to 33,959 participants aged 5-26 years (12,411 to 27,180 for those with European ancestry, defined by principal component analyses). We identified a genome-wide significant association with word reading (rs11208009, p=1.098 x 10-8) independent of known loci associated with intelligence or educational attainment. All five reading-/language-related traits had robust SNP-heritability estimates (0.13-0.26), and genetic correlations between them were modest to high. Using genomic structural equation modelling, we found evidence for a shared genetic factor explaining the majority of variation in word and nonword reading, spelling, and phoneme awareness, which only partially overlapped with genetic variation contributing to nonword repetition, intelligence and educational attainment. A multivariate GWAS was performed to jointly analyse word and nonword reading, spelling, and phoneme awareness, maximizing power for follow-up investigation. Genetic correlation analysis of multivariate GWAS results with neuroimaging traits identified association with cortical surface area of the banks of the left superior temporal sulcus, a brain region with known links to processing of spoken and written language. Analysis of evolutionary annotations on the lineage that led to modern humans showed enriched heritability in regions depleted of Neanderthal variants. Together, these results provide new avenues for deciphering the biological underpinnings of these uniquely human traits.

genomics↗