House mouse colonization patterns on the sub-Antarctic Kerguelen Archipelago suggest singular primary invasions and resilience against re-invasion

Starting from Western Europe, the house mouse (Mus musculus domesticus) has spread across the globe in historic times. However, most oceanic islands were colonized by mice only within the past 300 years. This makes them an excellent model for studying the evolutionary processes during early stages of new colonization. We have focused here on the Kerguelen Archipelago, located within the sub-Antarctic area and compare the patterns with samples from other Southern Ocean islands

3D models related to the publication: “Molar wear in house mice: insight into diet preferences at an ecological time scale?”

This contribution contains 3D models of upper molar rows of house mice (Mus musculus domesticus) belonging to Western European commensal and Sub-Antarctic feral populations. These two groups are characterized by different patterns of wear and alignment of the three molars along the row, related to contrasted masticatory demand in relation with their diet. These models are analyzed in the following publication: Renaud et al 2023, “Molar wear in house mice, insight into diet preferences at an ecological time scale?”, https://doi.org/10.1093/biolinnean/blad09

The importance of urban areas in supporting vulnerable and endangered mammals

The fragmentation of habitats associated with urbanisation poses a significant threat to already vulnerable and endangered mammal species. While the county of Dorset has been identified as one of the UK’s biodiversity hotspots, it is characterised by large-scale urbanisation and intensive agriculture. Focusing on the largest urban area of Dorset—the conurbation of Bournemouth, Christchurch, and Poole—this study aims to investigate the importance of urban areas in supporting vulnerable and endangered mammals by comparing it to four other major land cover categories in the county: arable & horticulture, grassland, woodland, and heathland. The study utilises data collected by the county’s environmental records department through mainly volunteer-contributed ad-hoc sighting data of 10 872 georeferenced mammal records collected between 2000 and 2018. Our findings reveal that, despite having significantly different mammal communities to all other land covers, urban land cover was shown to host four out of five of the vulnerable and endangered species recorded in this study. These included the European rabbit (vulnerable on the IUCN red list), hazel dormouse (vulnerable on the UK red list), West European hedgehog (vulnerable on the UK red list) and European water vole (endangered on the UK red list). Our findings highlight the significance of urban areas as important habitats for mammal biodiversity, presenting an opportunity for the conservation of specific vulnerable and endangered species. Despite limitations in ad-hoc sighting data, our analysis indicates an overrepresentation of certain 'charismatic' species, like foxes and hedgehogs, in urban samples, likely due to their high intrinsic value to the population. While the recognition of urban habitats for 'red list' species is growing, it is also important to acknowledge the relative importance of charismatic species to urban human communities in conservation and management strategies

Environmental DNA reveals the temporal and spatial extent of spawning migrations of European shad in a highly fragmented river basin

1. Anthropogenic barriers on lowland rivers impede the spawning migrations of anadromous fishes, preventing access to historical spawning areas. In the cryptic European shads Alosa alosa and Alosa fallax (‘shad’ hereafter), this has resulted in population declines across their range. Conservation programmes aim to facilitate the passage of migrators over these barriers and so require baseline knowledge on spatial and temporal extent of current migrations. 2. Here, a shad-specific environmental DNA (eDNA) assay was used to quantify the spatial extent of shad spawning migrations in the River Severn basin, Western England. This basin is characterised by the presence of multiple anthropogenic barriers in the lower catchment. In 2017, the eDNA assay was piloted in the River Teme, an important shad spawning tributary, and then applied in 2018 and 2019 across the lower Severn basin. 3. In all years, shad DNA was detected between mid-May and mid-June, with the maximum spatial extent of shad distribution being in early June when shad eDNA was detected upstream of weirs that were generally considered as impassable. In 2018, this included the detection of shad above the most upstream weir on the main River Severn that required individual fish to have passed six weirs. 4. Although anthropogenic barriers inhibit the spawning migrations of shad, this eDNA assay revealed some highly vagile individuals might be able to ascend these barriers and migrate considerable distances upstream. This suggests that efforts to increase the permeability of these barriers could result in relatively high numbers of migrating shad reaching upstream spawning areas. These results demonstrate that this eDNA assay could be also utilised across their range, outside the study system, to further quantify the spatial extent of their spawning, including in highly fragmented rivers and those where shad are believed to only spawn occasionally and are rarely observed

Population genetics and demography of the endemic mouse species of Cyprus, Mus cypriacus

Mus cypriacus is one of three small palaeoendemic mammals that have survived the Mediterranean islands’ anthropization. This species, endemic to Cyprus, was described in 2006 and stands out as one of the last mammal species to have been discovered in Europe. Despite scarce data on its genetics, ecology, and life-history traits, Mus cypriacus is assessed as Least Concern LC in the IUCN Red List, partly due to its morphological similarity with the sympatric house mouse that prevented earlier identification. Our study uses mitochondrial and microsatellite markers to investigate this small rodent's population genetic structure and diversity. Our analysis did not identify any population genetic structure and suggested a high genetic diversity across Cyprus. When inferring habitat preference using sample locations, it appeared that M. cypriacus utilizes a diverse variety of habitats, covering more than 80% of the island. Although these results are encouraging for the conservation status of the species, they still need to be cautiously applied as potential threats may arise due to increasing habitat destruction and changes in land use. Consequently, our encouraging results should be applied judiciously. Additional ecological data are urgently needed to gain a more comprehensive understanding of this inconspicuous endemic species

Reconciling the biogeography of an invader through recent and historic genetic patterns: the case of topmouth gudgeon Pseudorasbora parva

© 2018 The Author(s) The genetic variability and population structure of introduced species in their native range are potentially important determinants of their invasion success, yet data on native populations are often poorly represented in relevant studies. Consequently, to determine the contribution of genetic structuring in the native range of topmouth gudgeon Pseudorasbora parva to their high invasion success in Europe, we used a dataset comprising of 19 native and 11 non-native populations. A total of 666 samples were analysed at 9 polymorphic microsatellite loci and sequenced for 597 bp of mitochondrial DNA. The analysis revealed three distinct lineages in the native range, of which two haplogroups were prevalent in China (100%), with a general split around the Qinling Mountains. Dating of both haplogroups closely matched past geological events. More recently, its distribution has been influenced by fish movements in aquaculture, resulting in gene flow between previously separated populations in Northern and Southern China. Their phylogeography in Europe indicate as few as two introductions events and two dispersal routes. Microsatellite data revealed native populations had higher genetic diversity than those in the invasive range, a contrast to previous studies on P. parva. This study confirms the importance of extensive sampling in both the native and non-native range of invasive species in evaluating the influence of genetic variability on invasion success

Positive Selection in East Asians for an EDAR Allele that Enhances NF-κB Activation

Genome-wide scans for positive selection in humans provide a promising approach to establish links between genetic variants and adaptive phenotypes. From this approach, lists of hundreds of candidate genomic regions for positive selection have been assembled. These candidate regions are expected to contain variants that contribute to adaptive phenotypes, but few of these regions have been associated with phenotypic effects. Here we present evidence that a derived nonsynonymous substitution (370A) in EDAR, a gene involved in ectodermal development, was driven to high frequency in East Asia by positive selection prior to 10,000 years ago. With an in vitro transfection assay, we demonstrate that 370A enhances NF-κB activity. Our results suggest that 370A is a positively selected functional genetic variant that underlies an adaptive human phenotype

Testing the thrifty gene hypothesis: the Gly482Ser variant in PPARGC1A is associated with BMI in Tongans

<p>Abstract</p> <p>Background</p> <p>The thrifty gene hypothesis posits that, in populations that experienced periods of feast and famine, natural selection favoured individuals carrying thrifty alleles that promote the storage of fat and energy. Polynesians likely experienced long periods of cold stress and starvation during their settlement of the Pacific and today have high rates of obesity and type 2 diabetes (T2DM), possibly due to past positive selection for thrifty alleles. Alternatively, T2DM risk alleles may simply have drifted to high frequency in Polynesians. To identify thrifty alleles in Polynesians, we previously examined evidence of positive selection on T2DM-associated SNPs and identified a T2DM risk allele at unusually high frequency in Polynesians. We suggested that the risk allele of the Gly482Ser variant in the <it>PPARGC1A </it>gene was driven to high frequency in Polynesians by positive selection and therefore possibly represented a thrifty allele in the Pacific.</p> <p>Methods</p> <p>Here we examine whether <it>PPARGC1A </it>is a thrifty gene in Pacific populations by testing for an association between Gly482Ser genotypes and BMI in two Pacific populations (Maori and Tongans) and by evaluating the frequency of the risk allele of the Gly482Ser variant in a sample of worldwide populations.</p> <p>Results</p> <p>We find that the Gly482Ser variant is associated with BMI in Tongans but not in Maori. In a sample of 58 populations worldwide, we also show that the 482Ser risk allele reaches its highest frequency in the Pacific.</p> <p>Conclusion</p> <p>The association between Gly482Ser genotypes and BMI in Tongans together with the worldwide frequency distribution of the Gly482Ser risk allele suggests that <it>PPARGC1A </it>remains a candidate thrifty gene in Pacific populations.</p

3D models related to the publication: Molar wear in house mice: insight into diet preferences at an ecological time scale?

This contribution contains 3D models of upper molar rows of house mice (Mus musculus domesticus) belonging to Western European commensal and Sub-Antarctic feral populations. These two groups are characterized by different patterns of wear and alignment of the three molars along the row, related to contrasted masticatory demand in relation with their diet. These models are analyzed in the following publication: Renaud et al 2023, "Molar wear in house mice, insight into diet preferences at an ecological time scale?", https://doi.org/10.1093/biolinnean/blad091

Molar wear in house mice: insight into diet preferences at an ecological timescale?

In molars without permanent eruption, wear deeply modifies the geometry of the crown. To test for a signature of diet on wear dynamics, the molar geometry was compared between commensal house mice, relying on an omnivorous-granivorous diet, and Sub-Antarctic relatives, characterized by a switch towards a more ‘predatory’ behaviour. Laboratory-bred offspring of commensal mice served as a reference by providing mice of known age. Molar geometry was quantified using dense 3D semi-landmark based descriptors of the whole molar row and the upper molar only. Laboratory offspring displayed a decreased rate of wear compared to their commensal relatives, due to reduced mastication in mice fed ad libitum. Sub-Antarctic mice displayed a similarly decreased rate of molar wear, in agreement with an optimization towards incisor biting to seize prey. Laboratory offspring and Sub-Antarctic mice were further characterized by straight molar rows, whereas in commensal mice, the erupting third molar deviated away from the longitudinal alignment with the other molars, due to masticatory loadings. Quantifying changes in molar geometry could thus contribute to trace subtle diet variations, and provide a direct insight into the constraints during mastication, shedding light on the functional role of adaptive changes in molar geometry