Biology subjects

Schneider, J. M.

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

6 recordsLinked to original sources

bioRxiv2026

Closely related, yet phenotypically different - Genome assemblies of two sister species of widow spiders: Latrodectus hasselti and L. katipo, Theridiidae

Widow spiders of the genus Latrodectus are important animals for biomedical, pest and conservation research. Here, we present the assembled genomes of two closely related Latrodectus species: the Australian L. hasselti and the New Zealand endemic L. katipo. The genome of L. katipo consists of 13 scaffolds likely corresponding to chromosomes (90% of the total length) and 1267 short scaffolds (10%). It has a total length of 1.5 Gbp and BUSCO of 94.9%. The genome of L. hasselti consists of 379 scaffolds and has a total length of 1.7 Gbp and a BUSCO score of 95.4%. The repeat content is very similar in both genomes with a total proportion of 37.2% for L. katipo and 39.9% for L. hasselti. Genome annotation predicted 12706 and 15111 genes for L. katipo and L. hasselti respectively. An ortholog analysis shows large overlap between orthogroups suggesting either duplication events in L. hasselti or loss of genes in L. katipo.

genomics↗

bioRxiv2025

Extra-genital wounding delays remating in the sexually cannibalistic springbok mantis

A fascinating consequence of sexual conflict in animals is the maintenance of traits in males that cause physical damage to females during mating interactions. Such harm is hypothesised to be either an adaptation that enhances male fitness, or a collateral side-effect of adaptations that benefit males in other contexts. Tests of these hypotheses have mostly focused on traumatic copulation, where males wound females internally with weaponised genitalia, despite the widespread occurrence of extra-genital injury inflicted by non-genitalic structures like teeth, fangs or claws. Here, we take advantage of the unique mating interactions of the sexually cannibalistic springbok mantis, Miomantis caffra, to investigate the evolution of extra-genital wounding. Males of this species use their foretibial claws to stab females in the abdomen while fighting back against cannibalistic attacks during mating attempts. If stabbing females is adaptive, we predicted that experimentally wounded females would alter their remating behaviour or reproductive scheduling to the benefit of their mates. We found that injured females did not differ in their attractiveness or remating likelihood compared to intact females, and did not show an enhanced propensity to attack second courting males. Injured females also showed no change in mortality, fecundity, or offspring production that would suggest terminal investment due to male manipulation through wounding. However, our experiments revealed a statistically significant delay in the timing of remating among injured females, which could be interpreted as a benefit to males if such a delay reduces sperm competition. But given that remating was not prevented, only deferred, the injury-induced delay we observed is unlikely to be ecologically important, although field studies would be required to confirm this. Taken together, our results suggest that extra-genital wounding in the springbok mantis is unlikely to be adaptive but may instead be a pleiotropic side-effect of males trying to avoid being cannibalised.

evolutionary biology↗

bioRxiv2021

Systems analysis of gut microbiome influence on metabolic disease in HIV and high-risk populations

Poor metabolic health, characterized by insulin resistance and dyslipidemia, is higher in people living with HIV and has been linked with inflammation, anti-retroviral therapy (ART) drugs, and ART-associated lipodystrophy (LD). Metabolic disease is associated with gut microbiome composition outside the context of HIV but has not been deeply explored in HIV infection nor in high-risk men who have sex with men (HR-MSM), who have a highly altered gut microbiome composition. Furthermore, the contribution of increased bacterial translocation and associated systemic inflammation that has been described in HIV-positive and HR-MSM individuals has not been explored. We used a multi-omic approach to explore relationships between impaired metabolic health, defined using fasting blood markers, gut microbes, immune phenotypes and diet. Our cohort included ART-treated HIV positive MSM with and without LD, untreated HIV positive MSM, and HR-MSM. For HIV positive MSM on ART, we further explored associations with the plasma metabolome. We found that elevated plasma lipopolysaccharide binding protein (LBP) was the most important predictor of impaired metabolic health and network analysis showed that LBP formed a hub joining correlated microbial and immune predictors of metabolic disease. Taken together, our results suggest the role of inflammatory processes linked with bacterial translocation and interaction with the gut microbiome in metabolic disease among HIV positive and negative MSM. Importance StatementThe gut microbiome in people living with HIV (PLWH) is of interest as chronic infection often results in long term comorbidities. Metabolic disease is prevalent in PLWH even in well-controlled infection and has been linked with the gut microbiome in previous studies, but little attention has been given to PLWH. Furthermore, integrated analyses that consider gut microbiome together with diet, systemic immune activation, metabolites, and demographics have been lacking. In a systems-level analysis of predictors of metabolic disease in PLWH and men who are at high risk of acquiring HIV, we found that increased LBP, an inflammatory marker indicative of compromised intestinal barrier function, was associated with worse metabolic health. We also found impaired metabolic health associated with specific dietary components, gut microbes, and host and microbial metabolites. This work lays the framework for mechanistic studies aimed at targeting the microbiome to prevent or treat metabolic endotoxemia in HIV-infected individuals.

microbiology↗

bioRxiv2020

Sex-Specific Genetic Architecture Of Behavioral Traits In A Spider

Sex differences in behavioral traits are common, but we know little about the role of sexual selection in shaping these traits. Estimating sex-specific genetic effects and cross-sex genetic correlations can provide insights into sex-specific selection and on whether evolution can shape independent expression of behavioral traits across the sexes. We conducted a quantitative genetic study in a sexually-size-dimorphic spider, Larinioides sclopetarius, which exhibits sex differences in adult life-styles. We observed pedigreed spiders for aggression, activity, exploration and boldness, and used animal models to disentangle genetic and environmental influences on these behaviors. We detected higher additive genetic variances in activity and aggression in males compared to females, but no sex differences in quantitative genetic estimates for exploration and boldness. The estimated mean cross-sex genetic correlation in all traits were close to zero suggesting these traits could have flexibility for sex-independent evolution. We note however, that the 95% credible intervals of cross-sex genetic correlation are large, and thus estimates uncertain. Our results imply that individual variation in aggression and activity might stem from sex-specific selection acting on these traits. The estimates of sex-specific additive genetic variation and cross-sex genetic correlation suggests their further sex-independent evolution. Taken together, our results support the notion that sexual selection can play an important role shaping behavioral traits.

evolutionary biology↗

bioRxiv2018

VOLARE: Visual analysis of disease-associated microbiome-immune system interplay

BackgroundRelationships between specific microbes and proper immune system development, composition, and function have been reported in a number of studies. However, researchers have discovered only a fraction of the likely relationships. High-dimensional \"omic\" methodologies such as 16S ribosomal RNA (rRNA) sequencing and Time-of-flight mass cytometry (CyTOF) immunophenotyping generate data that support generation of hypotheses, with the potential to identify additional relationships at a level of granularity ripe for further experimentation. Pairwise linear regressions between microbial and host immune features is one approach for quantifying relationships between \"omes\", and the differences in these relationships across study cohorts or arms. This approach yields a top table of candidate results. However, the top table alone lacks the detail that domain experts need to vet candidate results for follow-up experiments.\n\nResultsTo support this vetting, we developed VOLARE (Visualization Of LineAr Regression Elements), a web application that integrates a searchable top table, small in-line graphs illustrating the fitted models, a network summarizing the top table, and on-demand detailed regression plots showing full sample-level detail. We applied VOLARE to three case studies--microbiome:cytokine data from fecal samples in HIV, microbiome:cytokine data in inflammatory bowel disease and spondyloarthritis, and microbiome:immune cell data from gut biopsies in HIV. We present both patient-specific phenomena and relationships that differ by disease state. We also analyzed interaction data from system logs to characterize usage scenarios. This log analysis revealed that, in using VOLARE, domain experts frequently generated detailed regression plots, suggesting that this detail aids the vetting of results.\n\nConclusionsSystematically integrating microbe:immune cell readouts through pairwise linear regressions and presenting the top table in an interactive environment supports the vetting of results for scientific relevance. VOLARE allows domain experts to control the analysis of their results, screening dozens of candidate relationships with ease. This interactive environment transcends the limitations of a static top table.

bioinformatics↗

bioRxiv2018

An exploration of Prevotella-rich microbiomes in HIV and men who have sex with men

BackgroundGut microbiome characteristics associated with HIV infection are of intense research interest but a deep understanding has been challenged by confounding factors across studied populations. Notably, a Prevotella-rich microbiome described in HIV-infected populations is now understood to be common in men who have sex with men (MSM) regardless of HIV status, but driving factors and potential health implications are unknown.\n\nResultsHere we further define the MSM-associated gut microbiome and describe compositional differences between the fecal microbiomes of Prevotella-rich MSM and non-MSM that may underlie observed pro-inflammatory properties. Furthermore, we show relatively subtle gut microbiome changes in HIV infection in MSM and women that include an increase in potential pathogens that is ameliorated with antiretroviral therapy (ART). Lastly, using a longitudinal cohort, we describe microbiome changes that happen after ART initiation.\n\nConclusionsThis study provides an in-depth characterization of microbiome differences that occur in a US population infected with HIV and demonstrates the degree to which these differences may be driven by lifestyle factors, ART and HIV infection itself. Understanding microbiome compositions that occur with sexual behaviors that are high-risk for acquiring HIV and untreated and ART-treated HIV infection will guide the investigation of immune and metabolic functional implications to ultimately target the microbiome therapeutically.

microbiology↗