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Adaptation of Pelage Color and Pigment Variations in Israeli Subterranean Blind Mole Rats, Spalax ehrenbergi. (2013) Adaptation of Pelage Color and Pigment Variations in Israeli Subterranean Blind Mole Rats, Spalax ehrenbergi. (2013) Correction: Adaptation of Pelage Color and Pigment Variations in Israeli Subterranean Blind Mole Rats, Spalax Ehrenbergi.

Phenotypic convergence across distantly related taxa can be driven by similar selective pressures from the environment or intrinsic constraints. The roles of these processes on physiological strategies, such as homeothermy, are poorly understood. We studied the evolution of thermal properties of mammalian pelage in a diverse community of rodents inhabiting the Mojave Desert, USA. We used a heat flux device to measure the thermal insulation of museum specimens and determined whether thermal properties were associated with habitat preferences while assessing phylogenetic dependence. Species that prefer arid habitats exhibited lower conductivity and thinner pelage relative to species with other habitat preferences. Despite being thinner, the pelage of arid species exhibited comparable insulation to the pelage of the other species due to its lower conductivity. Thus, arid species have insulative pelage while simultaneously benefitting from thin pelage that promotes convective cooling. We found no evidence of intrinsic constraints or phylogenetic dependence, indicating pelage readily evolves to environmental pressures. Thermoregulatory simulations demonstrated that arid specialists reduced energetic costs required for homeothermy by 14.5% by evolving lower conductivity, providing support for adaptive evolution of pelage. Our study indicates that selection for lower energetic requirements of homeothermy has shaped evolution of pelage thermal properties.

Background The unique pelage composition and developmental pattern endow hairy sheep with superior heat tolerance and minimized wool-shearing needs, compared with coarse-woolly sheep. However, the genetic mechanisms underlying pelage differentiation between these two sheep types remain incompletely understood to date, thereby limiting the development of molecular breeding strategies for cultivating climate-resilient and cost-effective sheep breeds in climate-changing era. Results Through integrated histomorphometric and transcriptomic analysis of Australian White Sheep (AWS, hairy phenotype) and Hu Sheep (HS, coarse-woolly phenotype), we identified three distinct evolutionarily conserved fiber types in AWS (heavily medullated kemp, medullated crimp hair, and non-medullated wool). In contrast, HS exhibited a bimodal fiber distribution without kemp fibers. Compared with AWS, HS had significantly longer hair fibers and markedly reduced subcutaneous adiposity. Transcriptomic profiling identified 370 differentially expressed genes (DEGs): genes enriched in AWS (e.g., DGAT2L6 , FOXO6 , CIDEA , ADIG ) were clustered in lipid metabolism pathways, while genes upregulated in HS (e.g., CSN2 , LOC101102413 , CSF3R , CXCR2 ) were significantly associated with immunomodulatory functions. Additionally, hair intermediate filament- and matrix-associated candidate genes (e.g., LOC114113348 / KAP20-2 , LOC101111178 / KRT6A ) and EDA2R exhibited breed-specific expression patterns, which were respectively linked to differences in fiber curvature and length. Conclusion Our integrated analysis identifies subcutaneous adiposity and immunoregulation as novel potential key modulators of pelage phenotype divergence between hairy and coarse-woolly sheep—with candidate genes (e.g., KAP20-2 , KRT6A , EDA2R ) linked to breed-specific fiber traits (e.g., curvature, length). The identified genetic signatures further offer potential actionable targets for precision breeding of climate-resilient and cost-effective sheep, addressing the gap in molecular strategies for pelage-related traits improvement.

Sigmodon hispidus Say and Ord, 1825, the Hispid Cotton Rat, is a sigmodontine rodent with small ears, black eyes and feet, dense brownish-black pelage with bands of yellow just below the black tips, gray hairs on the ventrum, and a tail about 40% of total length. This account is an update of Mammalian Species 158 on the subject species by Guy N. Cameron and Stephen R. Spencer (1981), incorporating more than 160 new references, most since 1981. Sigmodon hispidus, 1 of 4 species in this Neotropical genus in the United States, has an expanding distribution, especially in the central states, and populations in 3 locations in northern Mexico. Sigmodon hispidus is classified as “Least Concern” (LC) on the International Union for Conservation of Nature Red List.

The degree of introgressive hybridization between the Scottish wildcat and domestic cat has long been suspected to be advanced. Here, we use a 35‐SNP‐marker test, designed to assess hybridization between wildcat and domestic cat populations in Scotland, to assess a database of 295 wild‐living and captive cat samples, and test the assumptions of the test using 3,097 SNP markers generated independently in a subset of the data using ddRAD. We discovered that despite increased genetic resolution provided by these methods, wild‐living cats in Scotland show a complete genetic continuum or hybrid swarm structure when judged against reference data. The historical population of wildcats, although hybridized, clearly groups at one end of this continuum, as does the captive population of wildcats. The interpretation of pelage scores against nuclear genetic data continues to be problematic. This is probably because of a breakdown in linkage equilibrium between wildcat pelage genes as the two populations have become increasingly mixed, meaning that pelage score or SNP score alone is poor diagnostic predictors of hybrid status. Until better tools become available, both should be used jointly, where possible, when making management decisions about individual cats. We recommend that the conservation community in Scotland must now define clearly what measures are to be used to diagnose a wildcat in the wild in Scotland, if future conservation action is to be effective.

We studied the relationship between the variability and contemporary distribution of pelage phenotypes in one of most widely distributed felid species and an array of environmental and demographic conditions. We collected 672 photographic georeferenced records of the Eurasian lynx throughout Eurasia. We assigned each lynx coat to one of five phenotypes. Then we fitted the coat patterns to different environmental and anthropogenic variables, as well as the effective geographic distances from inferred glacial refugia. A majority of lynx were either of the large spotted (41.5%) or unspotted (uniform, 36.2%) phenotype. The remaining patterns (rosettes, small spots and pseudo-rosettes) were represented in 11.0%, 7.4%, and 3.9% of samples, respectively. Although various environmental variables greatly affected lynx distribution and habitat suitability, it was the effect of least-cost distances from locations of the inferred refugia during the Last Glacial Maximum that explained the distribution of lynx coat patterns the best. Whereas the occurrence of lynx phenotypes with large spots was explained by the proximity to refugia located in the Caucasus/Middle East, the uniform phenotype was associated with refugia in the Far East and Central Asia. Despite the widely accepted hypothesis of adaptive functionality of coat patterns in mammals and exceptionally high phenotypic polymorphism in Eurasian lynx, we did not find well-defined signs of habitat matching in the coat pattern of this species. Instead, we showed how the global patterns of morphological variability in this large mammal and its environmental adaptations may have been shaped by past climatic change.

Identifying the genetic basis of repeatedly evolved traits provides a way to reconstruct their evolutionary history and ultimately investigate the predictability of evolution. Here, we focus on the oldfield mouse (Peromyscus polionotus), which occurs in the southeastern United States, where it exhibits considerable color variation. Dorsal coats range from dark brown in mainland mice to near white in mice inhabiting sandy beaches; this light pelage has evolved independently on Florida’s Gulf and Atlantic coasts as camouflage from predators. To facilitate genomic analyses, we first generated a chromosome-level genome assembly of Peromyscus polionotus subgriseus. Next, in a uniquely variable mainland population (Peromyscus polionotus albifrons), we scored 23 pigment traits and performed targeted resequencing in 168 mice. We find that pigment variation is strongly associated with an ∼2-kb region ∼5 kb upstreamof the Agouti signaling protein coding region. Using a reporter-gene assay, we demonstrate that this regulatory region contains an enhancer that drives expression in the dermis of mouse embryos during the establishment of pigment prepatterns. Moreover, extended tracts of homozygosity in this Agouti region indicate that the light allele experienced recent and strong positive selection. Notably, this same light allele appears fixed in both Gulf and Atlantic coast beach mice, despite these populations being separated by >1,000 km. Together, our results suggest that this identified Agouti enhancer allele has been maintained in mainland populations as standing genetic variation and from there, has spread to and been selected in two independent beach mouse lineages, thereby facilitating their rapid and parallel evolution.

1. The challenges associated with monitoring low-density carnivores across large landscapes have limited the ability to implement and evaluate conservation and management strategies for such species. Non-invasive sampling techniques and advanced statistical approaches have alleviated some of these challenges and can even allow for spatially explicit estimates of density, one of the most valuable wildlife monitoring tools. 2. For some species, individual identification comes at no cost when unique attributes (e.g. pelage patterns) can be discerned with remote cameras, while other species require viable genetic material and expensive laboratory processing for individual assignment. Prohibitive costs may still force monitoring efforts to use species distribution or occupancy as a surrogate for density, which may not be appropriate under many conditions. 3. Here, we used a large-scale monitoring study of fisher Pekania pennanti to evaluate the effectiveness of occupancy as an approximation to density, particularly for informing harvest management decisions. We combined remote cameras with baited hair snares during 2013-2015 to sample across a 70 096-km² region of western New York, USA. We fit occupancy and Royle-Nichols models to species detection-non-detection data collected by cameras, and spatial capture-recapture (SCR) models to individual encounter data obtained by genotyped hair samples. Variation in the state variables within 15-km² grid cells was modelled as a function of landscape attributes known to influence fisher distribution. 4. We found a close relationship between grid cell estimates of fisher state variables from the models using detection-non-detection data and those from the SCR model, likely due to informative spatial covariates across a large landscape extent and a grid cell resolution that worked well with the movement ecology of the species. Fisher occupancy and density were both positively associated with the proportion of coniferous-mixed forest and negatively associated with road density. As a result, spatially explicit management recommendations for fisher were similar across models, though relative variation was dampened for the detection-non-detection data. 5. Synthesis and applications. Our work provides empirical evidence that models using detection-non-detection data can make similar inferences regarding relative spatial variation of the focal population to models using more expensive individual encounters when the selected spatial grain approximates or is marginally smaller than home range size. When occupancy alone is chosen as a cost-effective state variable for monitoring, simulation and sensitivity analyses should be used to understand how inferences from detection-non-detection data will be affected by aspects of study design and species ecology.

Changing from summer-brown to winter-white pelage or plumage is a crucial adaptation to seasonal snow in more than 20 mammal and bird species. Many of these species maintain nonwhite winter morphs, locally adapted to less snowy conditions, which may have evolved independently. Mountain hares (Lepus timidus) from Fennoscandia were introduced into the Faroe Islands in 1855. While they were initially winter-white, within ∼65 y all Faroese hares became winter-gray, a morph that occurs in the source population at low frequency. The documented population history makes this a valuable model for understanding the genetic basis and evolution of the seasonal trait polymorphism. Through whole-genome scans of differentiation and single-nucleotide polymorphism (SNP) genotyping, we associated winter coat color polymorphism to the genomic region of the pigmentation gene Agouti, previously linked to introgression-driven winter coat color variation in the snowshoe hare (Lepus americanus). Lower Agouti expression in the skin of winter-gray individuals during the autumn molt suggests that regulatory changes may underlie the color polymorphism. Variation in the associated genomic region shows signatures of a selective sweep in the Faroese population, suggesting that positive selection drove the fixation of the variant after the introduction. Whole-genome analyses of several hare species revealed that the winter-gray variant originated through introgression from a noncolor changing species, in keeping with the history of ancient hybridization between the species. Our findings show the recurrent role of introgression in generating winter coat color variation by repeatedly recruiting the regulatory region of Agouti to modulate seasonal coat color change.

Background Hair follicle mesenchymal stem cells (HF-MSCs) have great potential for cell therapy. Traditional method to isolate whisker HF-MSC is time-consuming and few in cell numbers. How to quickly and conveniently obtain a large number of HF-MSC for experimental research is a problem worth exploring. Methods Two-step Ficoll Density Gradient Sedimentation (FDGS) was performed to isolate pelage HF-MSC from adult mice. The characteristic of the isolated cells was identified and compared with whisker HF-MSC by immunofluorescence staining, flow cytometry, three-lineage differentiation and hair follicle reconstruction. Pelage HF-MSC and exosomes were injected into the dorsal skin of mice as well as hair follicle organ culture to explore its role in promoting hair growth. The cells and exosomes distribution were located by immunofluorescence staining. Results Isolated pelage HF-MSC expressed similar markers (ALP, Versican, NCAM, Nestin), showed similar growth pattern, possessed similar mesenchymal stem cells function and hair follicle induction ability as whisker HF-MSC. A large number of cells can be obtained with fewer mice compared to traditional method. Injected pelage HF-MSC promoted hair growth by secreting exosomes. Conclusion A large number of Pelage HF-MSC can be isolated by FDGS, which can promote hair growth by secreting exosomes which may target the dermal papilla and hair matrix region of host hair follicle.