Biology subjects

Dugdale, H.

Publications and source records attributed to Dugdale, H..

4 recordsLinked to original sources

bioRxiv2025

Parental age effects on offspring telomere length across vertebrates: a meta-analysis

Telomeres shorten with advancing age in numerous species, and shorter telomeres are linked to increased mortality risk. While parental age at conception can influence offspring telomere length, the magnitude and direction of this effect differ across studies, species, and parental sexes. A significant knowledge gap therefore exists in understanding how parental age influences offspring telomere length across vertebrates. To address this knowledge gap, we conducted a systematic review and meta-analysis to examine the effects of paternal and maternal age at conception on offspring telomere length, incorporating 99 effect sizes from 30 human studies and 49 effect sizes from 12 non-human vertebrates. Within the human studies, there was a positive overall parental age effect on offspring telomere length, while no effect was found in the non-human vertebrate studies after adjusting for study, estimate, and phylogenetic effects. There was considerable heterogeneity in both human and non-human studies. In human studies, heterogeneity was mainly attributed to between-study variance, and in non-human studies to phylogeny. Parental age effect estimates were correlated with the laboratory methods used for measuring telomere length in all studies. In human studies, the interaction between parental sex and offspring sex, and the cell type used for telomere extraction affected the parental age effect estimates. In non-human vertebrates, the parental age effects were more positive when the parents identity was controlled for in the study. We recommend that future research be conducted on a broader range of taxa, test for within-parent effects, and follow standardized reporting practices to enhance data comparability.

evolutionary biology↗

bioRxiv2025

Age- and sex-dependent sibling effects on early-life survival in preindustrial humans

Siblings are an important part of an individuals early-life environment and may therefore play an important role in shaping an individuals fitness. The quantification of sibling effects is challenging, especially in long-lived species with extended parental care and overlapping generations, such as humans. Here we quantify how the survival status, age, and sex of older siblings shape childhood survival across 2941 focal individuals born between 1750-1870 using historical parish data from Switzerland. While the total number of older siblings was not associated with an individuals childhood survival, distinguishing between siblings by their survival status, age, and sex revealed several associations, which in some cases also interacted with the sex of the focal individual: While older brothers close in age reduced the survival of girls but not boys, having more older sisters born close in age improved their younger siblings survival. Our results, therefore, show that sibling interactions play an important role in shaping early-life survival, and highlight that the strength and direction of these effects are context-dependent and can arise through biological and cultural factors. We encourage future studies on sibling interaction to consider siblings survival, age and sex, in both humans and other species.

evolutionary biology↗

bioRxiv2023

Human light meromyosin mutations linked to skeletal myopathies disrupt the coiled coil structure and myosin head sequestration

Myosin heavy chains encoded by MYH7 and MYH2 are among the most abundant proteins in human skeletal muscle. After decades of intense research using a wide range of biophysical and biological approaches, their functions have begun to be elucidated. Despite this, it remains unclear how mutations in these genes and resultant proteins disrupt myosin structure and function, inducing pathological states and skeletal myopathies termed myosinopathies. Here, we have analysed the effects of several common MYH7 and MYH2 mutations located in light meromyosin (LMM) using a broad range of approaches. We determined the secondary structure and filament forming capabilities of expressed and purified LMM constructs in vitro, performed in-silico modelling of LMM constructs, and evaluated the incorporation of eGFP-myosin heavy chain constructs into sarcomeres in cultured myotubes. Using muscle biopsies from patients, we applied Mant-ATP chase protocols to estimate the proportion of myosin heads that were super-relaxed, X-ray diffraction measurements to estimate myosin head order and myofibre mechanics to investigate contractile function. We found that human MYH7 and MYH2 LMM mutations commonly disrupt myosin coiled-coil structure and packing of filaments in vitro; decrease the myosin super-relaxed state in vivo and increase the basal myosin ATP consumption; but are not associated with myofibre contractile deficits. Altogether, these findings indicate that the structural remodelling resulting from LMM mutations induces a pathogenic state in which formation of shutdown heads is impaired, thus increasing myosin head ATP demand in the filaments, rather than affecting contractility. These key findings will help in the design of future therapies for myosinopathies.

physiology↗

bioRxiv2023

A major myna problem; invasive predator removal benefits female survival and population growth of a translocated island endemic

Invasive predators are a major driver of extinctions and continue to threaten native populations worldwide. Island eradications of (mostly mammalian) invasive predators have facilitated the (re)establishment of numerous island-endemic populations. Other invasive taxa, such as some predatory birds, could pose a more persistent threat due to their ability to fly and actively re-invade even remote and isolated islands. However, the impact of invasive predatory birds has been largely overlooked. We report on a novel sex-specific impact of an invasive-nest predator, the common myna (Acridotheres tristis), on a reintroduced population of Seychelles warblers (Acrocephalus sechellensis); translocated from Cousin Island to Denis Island in 2004. Regular post-translocation monitoring revealed that female mortality was 20% higher than males, leading to a 60-70% male-biased population sex-ratio between 2005-2015. This was attributed to mynas inflicting severe injuries to incubating female warblers while attempting to prey upon eggs in their nests. These effects likely contributed to the slower-than-expected population growth observed (relative to previous translocations of Seychelles warblers to other islands) over the same period. An eradication programme beginning in 2011 removed all mynas from Denis by 2015. Subsequently, we observed a balancing of sex-specific survival and the population sex-ratio of Seychelles warblers and, consequently, accelerated population growth. This study demonstrates the importance of assessing the threat posed by all invasive taxa (not just mammals) to island conservation. Furthermore, we show how extended monitoring is needed to identify problems, and develop solutions, post-translocation.

ecology↗