![]() ![]() Impacts of urbanization combine both the rapid destruction of natural habitats for infrastructure and their slow degradation through conversion to parks and gardens. Urbanization is therefore considered a major global threat to biodiversity, as well as a driver of evolutionary change. Urban cover is predicted to increase by 285% across the world from 2000 to 2030, when an extra 5.9 million km 2 of land is likely to be converted to urban use. Overall, our results provide evidence of local adaptation to urbanization in the face of gene flow in a highly mobile insect pollinator. We nevertheless identified several loci under directional selection, a subset of which was associated with urban land use, including the percentage of impervious surface surrounding each sampling site. Overall, genetic differentiation among sites was low and there was no obvious genome-wide genetic structuring, suggesting the absence of strong effects of urbanization on gene flow. Here, using 110 314 single nucleotide polymorphisms generated by restriction-site-associated DNA sequencing, we investigated the genome-wide effects of urbanization on putative neutral and adaptive genomic diversity in a major insect pollinator, Bombus lapidarius, collected from nine German cities and nine paired rural sites. The combination of these effects constitutes a challenge for both the survival and persistence of many native species, while also imposing altered selective regimes. The CNV markers analysis clearly confirmed the SNP results.Urbanization is considered a global threat to biodiversity the growth of cities results in an increase in impervious surfaces, soil and air pollution, fragmentation of natural vegetation and invasion of non-native species, along with numerous environmental changes, including the heat island phenomenon. The genetic variability found using SNP is comparable with that found by other authors in the same breeds using microsatellite markers. ![]() white and black) and the Bionda Piemontese and Bianca di Saluzzo breeds are closely related. All the approaches using SNP data showed that the Siciliana breed clearly differentiate from other populations, the Livornese breed separates into two distinct groups according to the feather colour (i.e. The CNV map was built on a total of 1003 CNV found in individual samples, after grouping by overlaps, resulting in 564 unique CNV regions (344 gains, 213 losses and 7 complex), for a total of 9.43 Mb of sequence and 1.03% of the chicken assembly autosome. A hierarchical agglomerative clustering was applied in each population according to the absence or presence of definite CNV regions (CNV were grouped by overlapping of at least 1 bp). The individual-based CNV calling, based on log R ratio and B-allele frequency values, was done by the Hidden–Markov Model (HMM) of PennCNV software on autosomes. ![]() The genetic diversity within breeds was calculated using heterozygosity values (expected and observed) and with Wright’s F-statistics. The genetic relationship among animals was established with a principal component analysis. The results showed the genetic and genomic variability occurring among the six Italian chicken breeds. A total of 94 DNA samples genotyped with Axiom ® Genome-Wide Chicken Genotyping Array (Affymetrix) were used in the analyses. Genomic and genetic variation among six Italian chicken native breeds (Livornese, Mericanel della Brianza, Milanino, Bionda Piemontese, Bianca di Saluzzo and Siciliana) were studied using single nucleotide polymorphism (SNP) and copy number variants (CNV) as markers. ![]()
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