Biology subjects

Buerkner, P.-C.

Publications and source records attributed to Buerkner, P.-C..

4 recordsLinked to original sources

bioRxiv2026

High immune receptor clonality in melanoma-draining lymph nodes associates with immune dysfunction and poor survival

Tumor-draining lymph nodes (tdLNs) are critical hubs of anti-tumor immunity but are also vulnerable to tumor-mediated immunosuppression. We analyzed T cell and B cell receptor (TCR/BCR) repertoires and transcriptomes from sentinel and non-sentinel lymph nodes of patients with melanoma from a historical pre-immune checkpoint inhibitor cohort (1994-2002) and an independent contemporary validation cohort (2022-2024). Melanoma-positive lymph nodes exhibited increased immune receptor clonality compared with tumor-free nodes. While average clonality showed no consistent association with outcome, the presence of extreme high-clonality outliers in individual lymph nodes was strongly associated with poor melanoma-specific survival. These outliers were characterized by a loss of lymphocyte-related genes and activation markers, an enrichment of melanocytic transcripts, and the suppression of immune signaling pathways, consistent with local immune dysfunction. Increased clonality was confined to lymph nodes and not observed in the peripheral blood. T cell responses to melanocyte differentiation antigens were infre-quently shared between lymph nodes and peripheral blood, highlighting immune compartmentalization.

immunology↗

bioRxiv2025

Eight years of social and asocial learning synergistically shape orangutan diet profiles

Cultural learning permeates human skill and knowledge acquisition. To understand its significance for nonhuman animals, we must examine how social learning shapes the development of broad behavioral repertoires, and operates alongside other forms of learning. We analyzed nearly seven thousand records of behavioral indicators of social and individual learning across wild orangutans eight-year dependency period to assess their combined effects on ecological competence relevant for post-independence survival. Social learning was five times more frequent than individual learning and influenced subsequent learning for hours. Immatures varied substantially in their learning propensities and those with heightened social and individual learning propensities developed the most expansive diet profiles at independence. Our findings advance the science of cultural evolution by showing that multi-year social and individual learning synergistically shape great apes broad ecological competence.

animal behavior and cognition↗

bioRxiv2024

Sumatran orangutan mothers differ in the extent and trajectory of their expression of maternal behaviour

Mothers play a crucial role in the early development and survival of mammalian offspring, and differences in maternal care may differentially affect offsprings development. Whereas previous research has primarily focused on biological and socioecological factors to understand population-level variation in maternal behaviour, the individual as a source of variation remains understudied. We investigated between-individual variation in the average expression of, and plasticity in, six maternal behaviours in Sumatran orangutans, using 15 years of behavioural data. We found that mothers differed substantially in the average expression of four maternal behaviours, even after controlling for socioecological conditions, biological state characteristics, and the offsprings influence on these behaviours. Furthermore, not controlling for these confounding effects exaggerated or masked between-individual variation. Mothers also substantially differed in how they adjusted three of the maternal behaviours during offspring development, meaning that mothers differed in behavioural plasticity. Our results suggest that Sumatran orangutan mothers are constrained in the average expression of maternal behaviours and their plastic responses, potentially resulting in consistent differences among mothers, otherwise called maternal personality. Our findings highlight that individual variation around the population mean in maternal behaviour is more than noise and presents opportunities to study novel evolutionary processes that shape maternal behaviour.

animal behavior and cognition↗

bioRxiv2024

Maternal behavior in Sumatran orangutans (Pongo abelii) is modulated by mother-offspring characteristics and socioecological factors

Mammalian mothers flexibly invest in their offspring to maximize their lifetime fitness. Flexible maternal investment may be particularly important in large-brained species with prolonged maternal care - e.g., in great apes. We investigated the effects of socioecological factors and mother-offspring characteristics on nine maternal behaviors in wild Sumatran orangutans (Pongo abelii; N=22 mother-offspring pairs; over 11,200 hours of focal data; collected from 2007-2022) using generalized linear mixed models. The behaviors fall under four maternal functions: locomotory support (carrying), skill acquisition support (feeding in proximity, food transfer), protective proximity maintenance (body contact and proximity initiation, following), and independence promotion (body contact and proximity termination, avoiding). Mothers parity was not significantly associated with any maternal behavior. Mothers were more likely to show locomotory support, skill acquisition support, and protective proximity maintenance toward younger than older offspring; whereas they were more likely to promote independence in older than younger offspring. Mothers with male offspring were more likely to show skill acquisition support to their offspring than those with female offspring. With increasing food availability, skill acquisition support reduced. With increasing association size, mothers were more likely to show protective proximity maintenance and less likely to promote independence. When males were present, mothers were more likely to show locomotory support to their offspring. Sumatran orangutan mothers thus flexibly adjust offspring directed behavior in response to prevailing socioecological factors and mother-offspring characteristics. Our findings add support to the evolutionary theory that mammalian mothers flexibly invest in their offspring.

animal behavior and cognition↗