Data from: MHC variability in an isolated wolf population in Italy

Small, isolated populations may experience increased extinction risk due to reduced genetic variability at important functional genes, thus decreasing the population's adaptive potential. The major histocompatibility complex (MHC), a key immunological gene cluster, usually shows high variability maintained by positive or balancing selection in response to challenges by pathogens. Here we investigated for the first time, the variability of 3 MHC class II genes (DRB1, DQA1, and DQB1) in 94 samples collected from Italian wolves. The Italian wolf population has been long isolated south of the Alps and is presently recovering from a recent bottleneck that decreased the population to less than 100 individuals. Despite the bottleneck, Italian wolves show remarkable MHC variability with 6–9 alleles per locus, including 2 recently described alleles at DRB1. MHC sequences show signatures of historical selective pressures (high d N/d S ratio, ω > 1.74) but no evidence of ongoing selection. Variation at the MHC genes and 12 background microsatellite loci were not apparently affected by the recent bottleneck. Although MHC alleles of domestic dog origin were detected in 8 genetically admixed individuals, these alleles were rare or absent in nonadmixed wolves. Thus, despite known hybridization events between domestic dogs and Italian wolves, the Italian wolf population does not appear affected by deep introgression of domestic dog MHC alleles

Data from: Choosy wolves? Heterozygote advantage but no evidence of MHC-based disassortative mating

A variety of nonrandom mate choice strategies, including disassortative mating, are used by vertebrate species to avoid inbreeding, maintain heterozygosity and increase fitness. Disassortative mating may be mediated by the major histocompatibility complex (MHC), an important gene cluster controlling immune responses to pathogens. We investigated the patterns of mate choice in 26 wild-living breeding pairs of gray wolf (Canis lupus) that were identified through noninvasive genetic methods and genotyped at 3 MHC class II and 12 autosomal microsatellite (STR) loci. We tested for deviations from random mating and evaluated the covariance of genetic variables at functional and STR markers with fitness proxies deduced from pedigree reconstructions. Results did not show evidences of MHC-based disassortative mating. Rather we found a higher peptide similarity between mates at MHC loci as compared with random expectations. Fitness values were positively correlated with heterozygosity of the breeders at both MHC and STR loci, whereas they decreased with relatedness at STRs. These findings may indicate fitness advantages for breeders that, while avoiding highly related mates, are more similar at the MHC and have high levels of heterozygosity overall. Such a pattern of MHC-assortative mating may reflect local coadaptation of the breeders, while a reduction in genetic diversity may be balanced by heterozygote advantages

Genetic investigation of Italian domestic pigeons increases knowledge about the long-bred history of Columba livia (Aves: Columbidae)

In this study, we aimed to characterise the genetic diversity of Italian pigeon breeds and describe the relationships among them and other European lineages, conjecturing which processes have led to actual breeds. We analysed the eight most diffused Italian pigeon breeds in addition to 11 foreign lineages that could have shared common ancestors or have been used in the creation of the Italian breeds. We analysed 12 autosomal microsatellite loci in 427 samples collected from 19 breeds belonging to six main groups of domestic pigeons (tumblers and highflyers, structure, owls, wattle, utility and hen). Genetic variability did not differ considerably among breeds, with an average observed heterozygosity (HO) of 0.550 ± 0.072 (max = 0.661 in breed Sottobanca; min = 0.411 in breed Frillback). The 21.34% of total genetic variation found was partitioned among breeds. Italian pigeon breeds were assigned coherently to their respective groups of origin. The analysis supports the origin of homing pigeons from English Carrier and the existence of a close relationship between Old Dutch Capuchine and Italian Owl. Despite the differences in body size, pigeons of the breeds belonging to the hen group are genetically very similar. The sub-populations recognised by breeders inside Italian Owl and Triganino are not genetically supported and their identification as new breeds ought not to be yet proposed, although they are morphologically distinguishable. Consequently, it could also be discussed how the genetic characterisation of domestic lineages could give useful information in breeding and selection processes

Genetic investigation of Italian domestic pigeons increases knowledge about the long-bred history of Columba livia (Aves: Columbidae)

In this study, we aimed to characterise the genetic diversity of Italian pigeon breeds and describe the relationships among them and other European lineages, conjecturing which processes have led to actual breeds. We analysed the eight most diffused Italian pigeon breeds in addition to 11 foreign lineages that could have shared common ancestors or have been used in the creation of the Italian breeds. We analysed 12 autosomal microsatellite loci in 427 samples collected from 19 breeds belonging to six main groups of domestic pigeons (tumblers and highflyers, structure, owls, wattle, utility and hen). Genetic variability did not differ considerably among breeds, with an average observed heterozygosity (HO) of 0.550 ± 0.072 (max = 0.661 in breed Sottobanca; min = 0.411 in breed Frillback). The 21.34% of total genetic variation found was partitioned among breeds. Italian pigeon breeds were assigned coherently to their respective groups of origin. The analysis supports the origin of homing pigeons from English Carrier and the existence of a close relationship between Old Dutch Capuchine and Italian Owl. Despite the differences in body size, pigeons of the breeds belonging to the hen group are genetically very similar. The sub-populations recognised by breeders inside Italian Owl and Triganino are not genetically supported and their identification as new breeds ought not to be yet proposed, although they are morphologically distinguishable. Consequently, it could also be discussed how the genetic characterisation of domestic lineages could give useful information in breeding and selection processes

Data from: European wildcat populations are subdivided into five main biogeographic groups: consequences of Pleistocene climate changes or recent anthropogenic fragmentation?

Extant populations of the European wildcat are fragmented across the continent, the likely consequence of recent extirpations due to habitat loss and over-hunting. However, their underlying phylogeographic history has never been reconstructed. For testing the hypothesis that the European wildcat survived the Ice Age fragmented in Mediterranean refuges, we assayed the genetic variation at 31 microsatellites in 668 presumptive European wildcats sampled in 15 European countries. Moreover, to evaluate the extent of subspecies/population divergence and identify eventual wild × domestic cat hybrids, we genotyped 26 African wildcats from Sardinia and North Africa and 294 random-bred domestic cats. Results of multivariate analyses and Bayesian clustering confirmed that the European wild and the domestic cats (plus the African wildcats) belong to two well-differentiated clusters (average ФST = 0.159, rst = 0.392, P > 0.001; Analysis of molecular variance [AMOVA]). We identified from c. 5% to 10% cryptic hybrids in southern and central European populations. In contrast, wild-living cats in Hungary and Scotland showed deep signatures of genetic admixture and introgression with domestic cats. The European wildcats are subdivided into five main genetic clusters (average ФST = 0.103, rst = 0.143, P > 0.001; AMOVA) corresponding to five biogeographic groups, respectively, distributed in the Iberian Peninsula, central Europe, central Germany, Italian Peninsula and the island of Sicily, and in north-eastern Italy and northern Balkan regions (Dinaric Alps). Approximate Bayesian Computation simulations supported late Pleistocene–early Holocene population splittings (from c. 60 k to 10 k years ago), contemporary to the last Ice Age climatic changes. These results provide evidences for wildcat Mediterranean refuges in southwestern Europe, but the evolution history of eastern wildcat populations remains to be clarified. Historical genetic subdivisions suggest conservation strategies aimed at enhancing gene flow through the restoration of ecological corridors within each biogeographic units. Concomitantly, the risk of hybridization with free-ranging domestic cats along corridor edges should be carefully monitored

Genetic investigation of Italian domestic pigeons increases knowledge about the long-bred history of Columba livia (Aves: Columbidae)

In this study, we aimed to characterise the genetic diversity of Italian pigeon breeds and describe the relationships among them and other European lineages, conjecturing which processes have led to actual breeds. We analysed the eight most diffused Italian pigeon breeds in addition to 11 foreign lineages that could have shared common ancestors or have been used in the creation of the Italian breeds. We analysed 12 autosomal microsatellite loci in 427 samples collected from 19 breeds belonging to six main groups of domestic pigeons (tumblers and highflyers, structure, owls, wattle, utility and hen). Genetic variability did not differ considerably among breeds, with an average observed heterozygosity (HO) of 0.550 ± 0.072 (max = 0.661 in breed Sottobanca; min = 0.411 in breed Frillback). The 21.34% of total genetic variation found was partitioned among breeds. Italian pigeon breeds were assigned coherently to their respective groups of origin. The analysis supports the origin of homing pigeons from English Carrier and the existence of a close relationship between Old Dutch Capuchine and Italian Owl. Despite the differences in body size, pigeons of the breeds belonging to the hen group are genetically very similar. The sub-populations recognised by breeders inside Italian Owl and Triganino are not genetically supported and their identification as new breeds ought not to be yet proposed, although they are morphologically distinguishable. Consequently, it could also be discussed how the genetic characterisation of domestic lineages could give useful information in breeding and selection processes

Genetic investigation of Italian domestic pigeons increases knowledge about the long-bred history of Columba livia (Aves: Columbidae)

In this study, we aimed to characterise the genetic diversity of Italian pigeon breeds and describe the relationships among them and other European lineages, conjecturing which processes have led to actual breeds. We analysed the eight most diffused Italian pigeon breeds in addition to 11 foreign lineages that could have shared common ancestors or have been used in the creation of the Italian breeds. We analysed 12 autosomal microsatellite loci in 427 samples collected from 19 breeds belonging to six main groups of domestic pigeons (tumblers and highflyers, structure, owls, wattle, utility and hen). Genetic variability did not differ considerably among breeds, with an average observed heterozygosity (HO) of 0.550 ± 0.072 (max = 0.661 in breed Sottobanca; min = 0.411 in breed Frillback). The 21.34% of total genetic variation found was partitioned among breeds. Italian pigeon breeds were assigned coherently to their respective groups of origin. The analysis supports the origin of homing pigeons from English Carrier and the existence of a close relationship between Old Dutch Capuchine and Italian Owl. Despite the differences in body size, pigeons of the breeds belonging to the hen group are genetically very similar. The sub-populations recognised by breeders inside Italian Owl and Triganino are not genetically supported and their identification as new breeds ought not to be yet proposed, although they are morphologically distinguishable. Consequently, it could also be discussed how the genetic characterisation of domestic lineages could give useful information in breeding and selection processes

Data from: Towards a genome-wide approach for detecting hybrids: informative SNPs to detect introgression between domestic cats and European wildcats (Felis silvestris)

Endemic gene pools have been severely endangered by human-mediated hybridization, which is posing new challenges in the conservation of several vertebrate species. The endangered European wildcat is an example of this problem, as several natural populations are suffering introgression of genes from the domestic cat. The implementation of molecular methods for detecting hybridization is crucial for supporting appropriate conservation programs on the wildcat. In this study, genetic variation at 158 single-nucleotide polymorphisms (SNPs) was analyzed in 139 domestic cats, 130 putative European wildcats and 5 captive-bred hybrids (N=274). These SNPs were variable both in wild (HE=0.107) and domestic cats (HE=0.340). Although we did not find any SNP that was private in any population, 22 SNPs were monomorphic in wildcats and pairwise FCT values revealed marked differences between domestic and wildcats, with the most divergent 35 loci providing an average FCT>0.74. The power of all the loci to accurately identify admixture events and discriminate the different hybrid categories was evaluated. Results from simulated and real genotypes show that the 158 SNPs provide successful estimates of admixture, with 100% hybrid individuals (two to three generations in the past) being correctly identified in STRUCTURE and over 92% using the NEWHYBRIDS' algorithm. None of the unclassified cats were wrongly allocated to another hybrid class. Thirty-five SNPs, showing the highest FCT values, provided the most parsimonious panel for robust inferences of parental and first generations of admixed ancestries. This approach may be used to further reconstruct the evolution of wildcat populations and, hopefully, to develop sound conservation guidelines for its legal protection in Europe

Data from: Isolation by distance, resistance and/or clusters? Lessons learned from a forest-dwelling carnivore inhabiting a heterogeneous landscape

Landscape genetics provides a valuable framework to understand how landscape features influence gene flow and to disentangle the factors that lead to discrete and/or clinal population structure. Here, we attempt to differentiate between these processes in a forest-dwelling small carnivore [European pine marten (Martes martes)]. Specifically, we used complementary analytical approaches to quantify the spatially explicit genetic structure and diversity and analyse patterns of gene flow for 140 individuals genotyped at 15 microsatellite loci. We first used spatially explicit and nonspatial Bayesian clustering algorithms to partition the sample into discrete clusters and evaluate hypotheses of 'isolation by barriers' (IBB). We further characterized the relationships between genetic distance and geographical ('isolation by distance', IBD) and ecological distances ('isolation by resistance', IBR) obtained from optimized landscape models. Using a reciprocal causal modelling approach, we competed the IBD, IBR and IBB hypotheses with each other to unravel factors driving population genetic structure. Additionally, we further assessed spatially explicit indices of genetic diversity using sGD across potentially overlapping genetic neighbourhoods that matched the inferred population structure. Our results revealed a complex spatial genetic cline that appears to be driven jointly by IBD and partial barriers to gene flow (IBB) associated with poor habitat and interspecific competition. Habitat loss and fragmentation, in synergy with past overharvesting and possible interspecific competition with sympatric stone marten (Martes foina), are likely the main factors responsible for the spatial genetic structure we observed. These results emphasize the need for a more thorough evaluation of discrete and clinal hypotheses governing gene flow in landscape genetic studies, and the potential influence of different limiting factors affecting genetic structure at different spatial scales