Sex‐Dependent Influence of Major Histocompatibility Complex Diversity on Fitness in a Social Mammal

Parasite infections affect males and females differently across a wide range of species, often due to differences in immune responses. Generally, females tend to have stronger immune defences and lower parasite loads than males. The major histocompatibility complex (MHC) plays a crucial role in the adaptive immune response, and extensive research has explored how variation in this region influences infection and fitness outcomes. However, studies of sex‐specific relationships between MHC variation and infection are scarce, perhaps because MHC genes are located on the autosomes, which are shared by both sexes. Here, we provide evidence of sexually antagonistic selection in a wild, group‐living mammal—the banded mongoose. Using genetic and life history data collected from over 300 individuals across 25 years, we found that both MHC class I (MHC‐I) and MHC class II (MHC‐II) diversity influence lifetime reproductive success differently in males and females. Specifically, higher MHC diversity is linked to increased fitness in males but decreased fitness in females. Furthermore, MHC diversity did not differ between the sexes, indicating an unresolved genetic sexual conflict. Our findings demonstrate that sexually antagonistic selection acts on the MHC and may operate across both MHC classes but differently. This study contributes to the growing body of evidence that sex is a significant factor in shaping host immunity and fitness

Data from: Kin discrimination via odour in the cooperatively breeding banded mongoose

Kin discrimination is often beneficial for group-living animals as it aids in inbreeding avoidance and providing nepotistic help. In mammals, the use of olfactory cues in kin discrimination is widespread and may occur through learning the scents of individuals that are likely to be relatives, or by assessing genetic relatedness directly through assessing odour similarity (phenotype matching). We use scent presentations to investigate these possibilities in a wild population of the banded mongoose Mungos mungo, a cooperative breeder in which inbreeding risk is high and females breed communally, disrupting behavioural cues to kinship. We find that adults show heightened behavioural responses to unfamiliar (extra-group) scents than to familiar (within-group) scents. Interestingly, we found that responses to familiar odours, but not unfamiliar odours, varied with relatedness. This suggests that banded mongooses are either able to use an effective behavioural rule to identify likely relatives from within their group, or that phenotype matching is used in the context of within-group kin recognition but not extra-group kin recognition. In other cooperative breeders, familiarity is used within the group and phenotype matching may be used to identify unfamiliar kin. However, for the banded mongoose this pattern may be reversed, most likely due to their unusual breeding system which disrupts within-group behavioural cues to kinship

Banded mongoose scent presentation data for Dryad

The data file contains data collected from presentations of banded mongoose (Mungos mungo) anal gland secretion to familiar and unfamiliar conspecifics in Mweya (Uganda) in 2014. Response variables are: (1) Total marks: the number of scent marks deposited on or around the odour (within 30 cm), including urinating, depositing faeces and anal marking. (2) Contact: the time (s) spent inspecting the odour (nose within 30 cm). (3) Duration: the time (s) before returning to foraging behaviour, defined here as digging in topsoil/dung or vegetation or eating food items. Explanatory variables are shortened as follows: Recip = Recipient, and Odour = Odour Donor. The Age, Sex (1 = female, 0 = male), Pack (social group code), ID (identity code of the individual mongoose), and the Relatedness between the donor and recipient (calculated using up to 43 microsatellite loci)

Indirect evidence of an early mating advantage in wild cooperatively breeding male banded mongooses

Abstract Promiscuous females reduce male reproductive control. Males can attempt to monopolise access to these females, but distractions and sneaky rivals mean extra copulations cannot always be blocked. By mating first, males can obtain a headstart in sperm competition, but this may be negated by sperm storage and cryptic female choice mechanisms. We carry out an indirect rare test of an early mating advantage in a population of free-living wild animals. Using Bayesian GLMM analysis of a long-term life history database spanning 17 years, we show that banded mongoose males who interacted with females in earlier days of oestrus had a higher chance of siring their offspring compared with later rivals. An early mating advantage would intensify initial male-male competition and hence selection for male choice, as any initial mistake identifying preferred mating partners could see paternity lost to rivals

Sex-Dependent Influence of Major Histocompatibility Complex Diversity on Fitness in a Social Mammal

Schubert N, Nichols H, Mwanguhya F, et al. Sex-Dependent Influence of Major Histocompatibility Complex Diversity on Fitness in a Social Mammal. MOLECULAR ECOLOGY. 2025: e70058.Parasite infections affect males and females differently across a wide range of species, often due to differences in immune responses. Generally, females tend to have stronger immune defences and lower parasite loads than males. The major histocompatibility complex (MHC) plays a crucial role in the adaptive immune response, and extensive research has explored how variation in this region influences infection and fitness outcomes. However, studies of sex-specific relationships between MHC variation and infection are scarce, perhaps because MHC genes are located on the autosomes, which are shared by both sexes. Here, we provide evidence of sexually antagonistic selection in a wild, group-living mammal-the banded mongoose. Using genetic and life history data collected from over 300 individuals across 25 years, we found that both MHC class I (MHC-I) and MHC class II (MHC-II) diversity influence lifetime reproductive success differently in males and females. Specifically, higher MHC diversity is linked to increased fitness in males but decreased fitness in females. Furthermore, MHC diversity did not differ between the sexes, indicating an unresolved genetic sexual conflict. Our findings demonstrate that sexually antagonistic selection acts on the MHC and may operate across both MHC classes but differently. This study contributes to the growing body of evidence that sex is a significant factor in shaping host immunity and fitness

Indirect evidence of an early mating advantage in wild cooperatively breeding male banded mongooses

Promiscuous females reduce male reproductive control. Males can attempt to monopolise access to these females, but distractions and sneaky rivals mean extra copulations cannot always be blocked. By mating first, males can obtain a headstart in sperm competition, but this may be negated by sperm storage and cryptic female choice mechanisms. We carry out an indirect rare test of an early mating advantage in a population of free-living wild animals. Using Bayesian GLMM analysis of a long-term life history database spanning 17 years, we show that banded mongoose males who interacted with females in earlier days of oestrus had a higher chance of siring their offspring compared with later rivals. An early mating advantage would intensify initial male-male competition and hence selection for male choice, as any initial mistake identifying preferred mating partners could see paternity lost to rivals.</p

Variation in Lipid Peroxidation in the Ejaculates of Wild Banded Mongooses (Mungos mungo): A Test of the Oxidative Shielding Hypothesis

Reproductive activity is costly in terms of future reproduction and survival. Oxidative stress has been identified as a likely mechanism underlying this cost of reproduction. However, empirical studies have yielded the paradoxical observation that breeders often sustain lower levels of oxidative damage than non-breeders. The oxidative shielding hypothesis attempts to explain such data, and posits that breeders pre-emptively reduce levels of oxidative damage in order to protect their germ cells, and any resultant offspring, from harm caused by exposure to oxidative damage. While there is some empirical evidence of oxidative shielding in females, there have been no explicit tests of this hypothesis in males, despite evidence of the oxidative costs to the male reproductive effort and the vulnerability of sperm cells to oxidative damage. In this study, we assess lipid oxidative damage (malondialdehyde, MDA) in the ejaculates of reproducing and non-reproducing wild banded mongooses. We found that, among breeding males, ejaculate MDA levels were lower during mate competition compared to 2 months later, when individuals were not mating, which is consistent with the oxidative shielding hypothesis, and similar to findings in females. However, ejaculate MDA levels did not differ significantly between breeding and non-breeding individuals at the time of mating, contrary to expectation. The finding that ejaculate MDA was not higher in non-breeders may reflect individual differences in quality and hence oxidative stress. In particular, breeders were significantly older than non-breeders, which may obscure differences in oxidative damage due to reproductive investment. Further research is needed to establish the causal relationship between reproductive investment and oxidative damage in ejaculates, and the consequences for offspring development in banded mongooses and other species

Managing hypertension in a Rohingya refugee camp: a brief report

Non-communicable diseases have overtaken communicable diseases as the most common cause of death worldwide, with the majority of these deaths in low-income and middle-income countries. Hypertension alone causes over nine million deaths per year.Since 2017, around 750 000 Rohingya refugees have fled violence in Myanmar into Cox’s Bazar District in Bangladesh. We describe a quality improvement project focused on the management of hypertension in Rohingya refugees in three primary health facilities within the Rohingya refugee camps. The aim of the project was to create a sustainable hypertension service within existing primary care services.A number of plan–do–study–act cycles were performed to improve care, with methods including: creating a specialised clinic, writing a treatment algorithm, training of pharmacists, engaging community health workers and educational programmes for staff and patients.In 2020, 554 patients were engaged in the new hypertension service. Of these, 358 (64.6%) returned for follow-up at least once. Mean systolic blood pressure (BP) was 141.7 (SD 60.0) mm Hg and mean diastolic BP was 88.1 (SD 11.1) mm Hg. Patients engaged in treatment had a significant reduction of BP of 8.2 (95% CI 5.4 to 11.0)/6.0 (95% CI 4.1 to 7.9) mm Hg (p&lt;0.0001).Our project shows that it is possible to create a hypertension service in a challenging humanitarian crisis, which can successfully improve the control of hypertension, although retention in care can be difficult

Evaluation of a digital triage platform in Uganda: A quality improvement initiative to reduce the time to antibiotic administration.

BackgroundSepsis is the leading cause of death in children under five in low- and middle-income countries. The rapid identification of the sickest children and timely antibiotic administration may improve outcomes. We developed and implemented a digital triage platform to rapidly identify critically ill children to facilitate timely intravenous antibiotic administration.ObjectiveThis quality improvement initiative sought to reduce the time to antibiotic administration at a dedicated children's hospital outpatient department in Mbarara, Uganda.Intervention and study designThe digital platform consisted of a mobile application that collects clinical signs, symptoms, and vital signs to prioritize children through a combination of emergency triggers and predictive risk algorithms. A computer-based dashboard enabled the prioritization of children by displaying an overview of all children and their triage categories. We evaluated the impact of the digital triage platform over an 11-week pre-implementation phase and an 11-week post-implementation phase. The time from the end of triage to antibiotic administration was compared to evaluate the quality improvement initiative.ResultsThere was a difference of -11 minutes (95% CI, -16.0 to -6.0; p ConclusionA data-driven patient prioritization and continuous feedback for healthcare workers enabled by a digital triage platform led to expedited antibiotic therapy for critically ill children with sepsis. This platform may have a more significant impact in facilities without existing triage processes and prioritization of treatments, as is commonly encountered in low resource settings