Biology subjects

Lonergan, T.

Publications and source records attributed to Lonergan, T..

4 recordsLinked to original sources

bioRxiv2026

Early-life telomere length variation under changing developmental conditions in long-lived bats

Early-life conditions can shape molecular ageing processes, yet to what extent developmental variation in telomere length (TL) influences ageing trajectories remains unclear, particularly in long-lived mammals. We investigated how early-life environmental conditions and maternal age relate to juvenile TL and short-term survival in two long-lived bat species, Myotis myotis and Rhinolophus ferrumequinum. Using novel long-term datasets spanning ten years in M. myotis and five years in R. ferrumequinum, we measured relative telomere length (rTL) in juvenile wing tissue and applied sliding window analysis to identify sensitive climatic periods during development. In both species, early-life rTL varied significantly among years and was associated with short-term climatic conditions, with rainfall predicting rTL in both species and temperature acting in opposing directions: longer rTL with warmer conditions in M. myotis, and longer rTL at intermediate temperatures in R. ferrumequinum. Maternal age at conception showed little association with offspring TL in either species, although a weak positive sex-specific longitudinal effect was detected in R. ferrumequinum. Despite clear environmental influences on early-life rTL, we found no evidence that early-life rTL or early-life telomere change predicted short-term survival. Together, these results indicate that early-life telomere variation in bats reflects climatic conditions during development, providing novel insights into how early-life exposures could contribute to inter-individual differences in ageing trajectories in long-lived mammals.

molecular biology↗

bioRxiv2025

Quantifying maternal antibody transfer to colostrum and cord blood reveals virus-specific selectivity in dogs

BackgroundNeonatal infections are a leading cause of mortality in dogs, with up to 30% of puppies dying within the first three weeks of life. During this period of immune development, protection is highly dependent on maternal antibodies (MatAbs) transferred across the placenta and via colostrum. Despite the critical importance of this transfer, little is known about the biological or clinical factors that determine its magnitude, whether specific antibodies are preferentially transferred, or how these processes vary across a broad population of dogs. MethodsTo quantify and explore the determinants of MatAb transfer in dogs, we analyzed matched maternal serum, cord blood, and colostrum samples collected from 44 client-owned dams undergoing cesarean section at a university veterinary hospital. Total IgG and virus-specific antibodies against canine parvovirus (CPV) and canine distemper virus (CDV) were analyzed. We also evaluated the influence of maternal factors, including age, breed, body weight, parity and litter size on MatAb transfer efficiency. ResultsAcross this diverse population, we observed limited transplacental transfer of MatAbs (4.5-6% maternal titer), in agreement with previous studies and as expected with the endotheliochorial placenta of dogs. In contrast, virus-specific IgG was highly enriched in colostrum, with 10.7-fold (CPV) and 8.1-fold (CDV) increases relative to serum. Transfer efficiency was significantly greater for virus-specific antibodies than for total IgG (3.2-fold), suggesting selective enrichment of antiviral antibodies during colostrogenesis. Maternal serum antibody titer emerged as the primary factor influencing the efficiency of antibody transfer. ConclusionsThese findings provide the most comprehensive quantification to date of MatAb transfer routes in dogs, revealing preferential transfer of virus-specific IgG to colostrum and highlighting the crucial role of colostrum intake for neonatal immunity. This work establishes a foundation for identifying antibody characteristics that influence MatAb transfer efficiency and reiterates the importance of ensuring dams have adequate titers of virus-specific IgG prior to breeding.

immunology↗

bioRxiv2025

Defying expectations: sex-biased telomere dynamics and extended lifespan in the tropical bat species, Molossus molossus.

Telomeres are key biomarkers of cellular ageing, yet their dynamics remain poorly studied in tropical and short-lived bat species. Here, we present the first investigation of telomere length across age in Molossus molossus, a tropical bat historically categorised as the shortest-lived bat on record. Through a multi-year mark-recapture study in Gamboa, Panama, we sampled 492 individuals (n = 317 females, 175 males) and documented a female M. molossus surviving to at least 13 years of age, more than doubling the previously reported maximum lifespan of 5.6 years. Across the population, relative telomere length (rTL) showed no overall significant decline with age. No evidence was found for sex-specific rates of telomere attrition. Rather these results suggest that males and females follow parallel age-related telomere trajectories, with any sex differences primarily reflecting differences in mean telomere length rather than ageing dynamics. Overall, the findings here challenge previous assumptions about the lifespan and ageing biology of M. molossus. They demonstrate that telomere maintenance is not limited to temperate bats, show that sex differences in telomere biology are subtle and species-specific, and reinforce the value of long-term field studies for understanding ageing processes in the wild.

molecular biology↗

bioRxiv2025

Mechanisms of maternal antibody interference to rotavirus vaccination

Maternal antibodies (MatAbs) are transferred transplacentally during pregnancy and through breast milk after birth to provide protection whilst the neonatal immune response is immature. However, MatAbs also suppress the development of neonatal B cell responses via mechanisms that are not well defined. MatAbs can therefore result in poor vaccine performance in the infant, placing them at risk against potentially life-threatening pathogens such as rotavirus. It is essential we understand the mechanisms by which MatAbs interact with neonatal immunity, so that strategies can be developed to overcome this major vaccine issue. To investigate mechanisms of interference we developed a mouse model of neonatal oral rotavirus vaccination in the presence and absence of MatAbs. Oral vaccination with attenuated murine rotavirus induced robust neonatal antibody responses, whereas vaccination failed to induce seroconversion in the presence of MatAbs. Vaccination with heterologous strains, reduced MatAb titers and vaccination in Fc{gamma}RIIB knockout mice did not overcome interference. However, live vaccine replication was blocked in the presence of MatAbs and more rapid waning of MatAbs was observed following vaccination. This is indicative of premature vaccine clearance and likely reduced antigen encounter by B cells. Single-cell RNA sequencing of mesenteric lymph nodes revealed diminished plasma and germinal center B cell subpopulations as well as global reduction of interferon-stimulated genes in the presence of MatAbs. Our model has also enabled identification of strategies to reduce the effects of interference. In summary, we have tested multiple hypotheses for MatAb-mediated interference to rotavirus vaccination in a mouse model, and demonstrated that premature Fc{gamma}RIIB signaling and epitope masking are not the primary mechanisms of vaccine failure. Rather our data supports the conclusion that MatAb-mediated vaccine clearance is a key mechanism of interference to oral rotavirus vaccine.

immunology↗