72 research outputs found

    Determining the influence of different atmospheric circulation patterns on PM10 chemical composition in a source apportionment study

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    This study combines a set of chemometric analyses with a source apportionment model for discriminating the weather conditions, local processes and remote contributions having an impact on particulate matter levels and chemical composition. The proposed approach was tested on PM10 data collected in a semi-rural coastal site near Venice (Italy). The PM10 mass, elemental composition and the water soluble inorganic ions were quantified and seven sources were identified and apportioned using the positive matrix factorization: sea spray, aged sea salt, mineral dust, mixed combustions, road traffic, secondary sulfate and secondary nitrate. The influence of weather conditions on PM10 composition and its sources was investigated and the importance of air temperature and relative humidity on secondary components was evaluated. Samples collected in days with similar atmospheric circulation patterns were clustered on the basis of wind speed and direction. Significant differences in PM10 levels and chemical composition pointed out that the production of sea salt is strongly depending on the intensity of local winds. Differently, typical primary pollutants (i.e. from combustion and road traffic) increased during slow wind regimes. External contributions were also investigated by clustering the backward trajectories of air masses. The increase of combustion and traffic-related pollutants was observed when air masses originated from Central and Northwestern Europe and secondary sulfate was observed to rise when air masses had passed over the Po Valley. Conversely, anthropogenic contributions dropped when the origin was in the Mediterranean area and Northern Europe. The chemometric approach adopted can discriminate the role local and external sources play in determining the level and composition of airborne particulate matter and points out the weather circumstances favoring the worst pollution conditions. It may be of significant help in designing local and national air pollution control strategies

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

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    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

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

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    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)

    No full text
    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

    First core microsatellite panel identification in Apennine brown bears (Ursus arctos marsicanus): a collaborative approach

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    Abstract Background The low cost and rapidity of microsatellite analysis have led to the development of several markers for many species. Because in non-invasive genetics it is recommended to genotype individuals using few loci, generally a subset of markers is selected. The choice of different marker panels by different research groups studying the same population can cause problems and bias in data analysis. A priority issue in conservation genetics is the comparability of data produced by different labs with different methods. Here, we compared data from previous and ongoing studies to identify a panel of microsatellite loci efficient for the long-term monitoring of Apennine brown bears (Ursus arctos marsicanus), aiming at reducing genotyping uncertainty and allowing reliable individual identifications overtimes. Results We examined all microsatellite markers used up to now and identified 19 candidate loci. We evaluated the efficacy of 13 of the most commonly used loci analyzing 194 DNA samples belonging to 113 distinct bears selected from the Italian national biobank. We compared data from 4 different marker subsets on the basis of genotyping errors, allelic patterns, observed and expected heterozygosity, discriminatory powers, number of mismatching pairs, and probability of identity. The optimal marker set was selected evaluating the low molecular weight, the high discriminatory power, and the low occurrence of genotyping errors of each primer. We calibrated allele calls and verified matches among genotypes obtained in previous studies using the complete set of 13 STRs (Short Tandem Repeats), analyzing six invasive DNA samples from distinct individuals. Differences in allele-sizing between labs were consistent, showing a substantial overlap of the individual genotyping. Conclusions The proposed marker set comprises 11 Ursus specific markers with the addition of cxx20, the canid-locus less prone to genotyping errors, in order to prevent underestimation (maximizing the discriminatory power) and overestimation (minimizing the genotyping errors) of the number of Apennine brown bears. The selected markers allow saving time and costs with the amplification in multiplex of all loci thanks to the same annealing temperature. Our work optimizes the available resources by identifying a shared panel and a uniform methodology capable of improving comparisons between past and future studies

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

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    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)

    No full text
    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
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