Biology subjects

van Mastrigt, T.

Publications and source records attributed to van Mastrigt, T..

3 recordsLinked to original sources

bioRxiv2026

Quantifying circulation and antibody cross-reactivity for co-circulating flaviviruses: the case of Usutu and West Nile virus in blackbirds

Serological testing is important for assessing past exposure and immunity, but interpretation can be complicated by antibody cross-reactivity between closely related viruses. We assess this challenge for Usutu virus (USUV) and West Nile virus (WNV), flaviviruses that recently emerged in Europe. We analysed samples from wild blackbirds collected in the Netherlands between 2016-2022. Samples (N=1742) were screened using an NS1-based protein micro-array, with positives confirmed by Focus Reduction Neutralization Tests (FRNT). We jointly estimated seroprevalence and antibody responses by fitting a Bayesian latent-variable model to FRNT values. Estimates of homologous and cross-reactive antibody responses were used to improve interpretation of observed titres for serosurveillance. Estimated seroprevalence varied across time and regions between 4.9% (95%CrI 3.5-6.7) to 18.5% (95%CrI 14.9-22.7) for USUV and between 2.4% (95%CrI 1.3-3.8) to 6.4% (95%CrI 3.9-9.6) for WNV. These were 1.5 (USUV) to 2.4 times (WNV) higher than estimates based on the current threshold-based algorithm. USUV induced a higher antibody response and was more likely to induce a cross-reactive response than WNV. Our classification algorithm informed by these estimates showed high sensitivity (WNV: 0.88, USUV: 0.97) and specificity (both: >0.99). Our results illustrate how quantitative frameworks can improve serological interpretation in settings with co-circulating pathogens.

ecology↗

bioRxiv2024

DNA methylation associates with sex-specific effects of experimentally increased yolk testosterone in wild nestlings

Maternal hormones can profoundly impact offspring physiology and behaviour in sex-dependent ways. Yet little is known on the molecular mechanisms linking these maternal effects to offspring phenotypes. DNA methylation, an epigenetic mechanism, is suggested to facilitate maternal androgens effects. To assess whether phenotypic changes induced by maternal androgens associate with DNA methylation changes, we experimentally manipulated yolk testosterone levels in wild great tit eggs (Parus major) and quantified phenotypic and DNA methylation changes in the hatched offspring. Increased yolk testosterone levels decreased the begging probability, emphasised sex-differences in fledging mass and affected methylation at 763 CpG sites, but always in a sex-specific way. These sites associated with genes involved in growth, oxidative stress and reproduction, suggesting sex-specific trade-offs to balance the costs and benefits of exposure to high yolk testosterone levels. Future studies should assess if these effects extend beyond the nestling stage and impact fitness.

molecular biology↗

bioRxiv2021

Parental control: ecology drives plasticity in parental response to offspring signals

Different bird species have completely different parent-offspring interactions. When food is plentiful, the chicks that are begging the loudest are fed the most. When food is scarce, bird species instead feed the largest offspring. While this variation could be due to parents responding to signalling differently based on food availability, it could equally be due to offspring adjusting their behaviour, or to variation in information availability. We tested between these competing explanations experimentally, by manipulating food availability in a population of wild great tits, Parus major, while standardising offspring behaviour and size. We found that when food was more plentiful, parents were: (1) more likely to preferentially feed the chicks that were begging the most; and (2) less likely to preferentially feed larger chicks. In addition, we consistently found these same patterns, in a meta-analysis across 57 bird species. Overall, our results suggest that parents have more control over food distribution than offspring do, and that they flexibly adjust how they respond to both offspring signals and cues of offspring quality in response to food availability. Consequently, depending upon environmental conditions, predictably different signalling systems are favoured.

animal behavior and cognition↗