Biology subjects

Paredes, U.

Publications and source records attributed to Paredes, U..

3 recordsLinked to original sources

bioRxiv2025

Maternal rejecting of newborns is epigenetic, intergenerationally transmitted and associated with altered miRNAs expression in owl monkeys.

Spontaneous maternal rejection of offspring is a considered a behavioural pathology affecting human and non-human primates, often with lethal consequences for newborns, yet it is widespread and pervasive across taxa, induced by stress or stress vulnerability. In some species, events of rejection can trigger chains of rejection which replicate themselves through generations. In this study we hypothesized that rejecting behaviours in owl monkeys are triggered and epigenetic in nature, transmitted to descendants, and their manifestation is associated with altered miRNA expression. Analysis of multi-generational records revealed that individuals who experienced rejection in infancy were 1.9 times more likely to reject their own offspring compared to controls, confirming its triggered nature. Transmission appears induced by experience rather than solely explained by genetic relatedness, as non-rejected full siblings showed no increased rejection tendency. Transcriptomic analysis identified distinct microRNA signatures associated with epigenetically induced rejecting behaviours. In rejected adults that become rejectors of their own offspring, mml-miR-1296, involved in lipid metabolism was significantly downregulated. In the naive daughters of rejected-rejectors, upregulated mml-miR-125b-5p, previously identified as biomarker in humans exposed to early life trauma that also suffered behavioural pathology, was identified. In summary, these findings confirm the epigenetic nature of spontaneous rejecting, with robust intergenerational transmission, and accompanied by alteration of epigenetic marks across generations in owl monkeys.

animal behavior and cognition↗

bioRxiv2024

Global DNA Hypomethylation as a Biomarker of Accelerated Epigenetic Ageing in Primates

IntroductionEpigenetic clocks based on DNA methylation patterns provide a powerful tool for measuring biological ageing, but requiring genome-wide methylation data and high costs limits their broad application across species and populations. MethodsWe investigated whether simply quantifying global DNA methylation levels could serve as an inexpensive proxy for epigenetic ageing, using a captive colony of owl monkeys (Aotus nancymaae) using a colorimetric ELISA assay to measure proportional content of levels of blood and brain 5-methylcytosine (5-mC) across the genome, comparing owl monkeys with known exposures to ageing accelerators and controls. Resultswe found that global 5-mC declined significantly with chronological age in blood, and in the brain of parents. Notably, this age-related blood hypomethylation in individuals experiencing early life maternal rejection was accelerated. Parenting experience also accelerated DNA methylation loss with age, but this effect was specific to the brain and not seen in blood. Infection history did not impact blood 5-mC trajectories. Although multiple regression models did not replicate all findings, likely due to sample size constraints, our results demonstrate that global DNA hypomethylation tracks biological ageing in blood. DiscussionThis simple metric successfully detected accelerated epigenetic ageing induced by early adversity, as well as distinct patterns relating to reproductive investment in the brain - phenotypes typically identified by sophisticated epigenetic clocks. Quantifying global methylation thus provides a cost-effective alternative approach to assessing susceptibility to environmentally-driven accelerated ageing across primate species and populations where DNA methylation arrays or sequencing are impractical.

animal behavior and cognition↗

bioRxiv2024

Long-Term Quarantine is Associated with High Cortisol and Low DNA Methylation in New World monkeys

Quarantines prevent infectious disease spread during primate transport, fostering acclimatisation. Environmental stress can lead to altered physiology, health risks, and epigenetic changes in other primates. We analysed Peruvian Saguinus fuscicollis and Saimiri macrodon, immobilised for 10 months in quarantine during the COVID-19 crisis, and compared them to wild counterparts to determine effects of quarantine as a stressor in New World monkeys. MethodsBoth quarantine and wild samples were collected from two riverine islands near the city of Iquitos, situated in the Peruvian Amazon (Island Muyuy and Padre Island). Cortisol levels in hair were quantified using ELISA (n=37; quarantine n=16; wild=21), and global DNA methylation levels were assessed for epigenetic comparison in dried blood spots (n=45; Quarantine: n=23; Wild: n=22), also utilising ELISA. Two-way ANOVA was employed to explore the effect of quarantine on cortisol and DNA methylation, considering the effect of species, and sex differences on these measurements. ResultsCortisol analysis revealed a significant association between quarantine and elevated cortisol secretion when testing both species together and independently, with a greater difference between quarantine and wild for Saguinus fuscicollis. Quarantine was associated with global DNA hypomethylation when testing both species together, however, independent ANOVAs show there was no effect of quarantine on Saguinus fuscicollis, and a marginal significant effect of quarantine on Saimiri macrodon. DiscussionNew World monkey species displayed hormonal and epigenetic dysregulation 10-months after starting quarantine period, suggesting long-term physiological and genomic stress as a response to captivity. Species specific differences in stress adaptability might mediate observed effects.

animal behavior and cognition↗