A high-density genome-wide approach reveals novel genetic markers linked to small ruminant lentivirus susceptibility in sheep.

Visna/Maedi virus (VMV) is lentiviral disease of sheep responsible for severe production losses. Multiple genomic regions associated with infection were reported indicating genetic complexity. In this study, a combined genome-wide approach using a high-density SNP array has been performed, comparing VMV-infected (n = 78) and non-infected (n = 66) individuals of the Valle del Belice breed. The serological tests showed a seroprevalence of 26%. The comparison among results from different approaches (GWAS, Fisher's exact test and the FST analysis) revealed two association signals: on OAR03 close to the GRIN2B gene and on OAR05 close to the TMEM232 gene. To the best of our knowledge, there has been no previous association between these genes and lentiviral infection in any species. The GRIN2B gene plays a role in pain response, synaptic transmission, and receptor clustering, while TMEM232 is involved in the development of immune-related disorders. The results highlighted new aspects of the genetic complexity related to the resistance/susceptibility to VMV in sheep, confirming that studies on different breeds can lead to different results. The ideal approach for validation of the markers identified in our study is to use samples from a population independent from the discovery population with the same phenotype used in the discovery stage.

A 10-year retrospective analysis (2012-2021) of hospitalizations resulting from dog bites in Southern Italy.

This study aimed to describe the incidence and characteristics of dog-bite injury hospitalizations (DBIH) in the largest administrative region of Italy (Sicily) over the 10-year period: 2012-2021. Four hundred and forty-nine cases were analyzed. Patients were divided into seven age groups: preschoolers (0-5 years), school-age children (6-12 years), teenagers (13-19 years), young adults (20-39 years), middle-aged adults (40-59 years), old adults (60-74 years), and the elderly (≥75 years). Association among categorical variables (age, gender, principal injury location) was evaluated using chi-square tests, and mean differences for normally distributed variables were assessed using one-way analysis of variance. Finally, a Poisson regression general linear model (GLM) analysis was used to model incidence data. The results revealed that the incidence of DBIH per 100,000 population increased from 0.648 in 2012 (95%CI 0.565-0.731) to 1.162 in 2021 (95%CI 1.078-1.247, P < 0.01). Incidence for both male and female victims also increased over the studied period (P < 0.05). We found an increasing trend of incidence in young and middle-aged adults (P < 0.05 and P < 0.005 respectively). Moreover, the most frequently injured age group by dogs was the preschooler group and, whilst we found a lower risk of being injured for males older than 20 years, no difference with females was observed. The location of lesions depended on the age group (P < 0.001). The number of days of DBIH increased significantly with age (P < 0.01). The increase of DBIH represents a public health problem that requires the development of preventive approaches.

Migration and students' performance: detecting geographical differences following a curves clustering approach.

Students' migration mobility is the new form of migration: students migrate to improve their skills and become more valued for the job market. The data regard the migration of Italian Bachelors who enrolled at Master Degree level, moving typically from poor to rich areas. This paper investigates the migration and other possible determinants on the Master Degree students' performance. The Clustering of Effects approach for Quantile Regression Coefficients Modelling has been used to cluster the effects of some variables on the students' performance for three Italian macro-areas. Results show evidence of similarity between Southern and Centre students, with respect to the Northern ones.

A multivariate statistical test for differential expression analysis.

Statistical tests of differential expression usually suffer from two problems. Firstly, their statistical power is often limited when applied to small and skewed data sets. Secondly, gene expression data are usually discretized by applying arbitrary criteria to limit the number of false positives. In this work, a new statistical test obtained from a convolution of multivariate hypergeometric distributions, the Hy-test, is proposed to address these issues. Hy-test has been carried out on transcriptomic data from breast and kidney cancer tissues, and it has been compared with other differential expression analysis methods. Hy-test allows implicit discretization of the expression profiles and is more selective in retrieving both differential expressed genes and terms of Gene Ontology. Hy-test can be adopted together with other tests to retrieve information that would remain hidden otherwise, e.g., terms of (1) cell cycle deregulation for breast cancer and (2) "programmed cell death" for kidney cancer.

Activation-Induced Rigidity in Neurologically and Cognitively Healthy Individuals Aged 18-90 Years: A Cross-Sectional Study.

BACKGROUND: Rigidity is a key clinical feature of Parkinson's disease (PD), but in a very early phase of the disease it may be absent and can be enhanced through active movements of the arm contralateral to the one being tested. OBJECTIVE: To evaluate in a large cohort of neurologically and cognitively healthy (NCH) subjects aged 18-90 years if activation-induced rigidity (AR) is present in all age classes, and if there are biological differences between subjects showing AR (AR+) and not showing AR (AR-). METHODS: 2,228 NCH subjects categorized as young adult (18-44 years), adult (45-64 years), elderly (65-74 years), and old/oldest-old (75-90 years) were included in the analysis, and underwent brain MRI. White matter hyperintensities were assessed through two visual rating scales. Lacunes were also rated. Atrophy of the caudate nuclei and ventricular enlargement were assessed through the bicaudate ratio and the lateral ventricles to brain ratio. To elicit AR, the Froment's maneuver (FM) and the instructions of the UPDRS-ME were used. RESULTS: Among the sample, 1,689 (75.81%) subjects showed AR, of which 1,270 (57.00%) subjects showed AR by using FM, and 419 (18.81%) showed AR by using UPDRS-ME instructions. The latter subjects also showed AR by using FM. The number of AR+ subjects significantly increased with increasing age, regardless of the activation maneuver used. In each age class, the number of AR+ subjects was significantly higher by using the FM than the UPDRS-ME instructions. CONCLUSION: Our findings suggest that AR is likely to be one of the signs of the prodromal phase of PD.

APOE Genotypes and Brain Imaging Classes in Normal Cognition, Mild Cognitive Impairment, and Alzheimer's Disease: A Longitudinal Study.

OBJECTIVE: To evaluate in 419 stroke-free cognitively normal subjects (CN) aged 45-82 years covering during a long prospective study (11.54 ± 1.47 years) the preclinical to dementia spectrum: 1) the distribution of small vessel disease (V) and brain atrophy (A) aggregated as following: V-/A-, V-/A+, V+/A-, V+/A+; 2) the relationship of these imaging classes with individual apolipoprotein E (APOE) genotypes; 3) the risk of progression to Alzheimer Disease (AD) of the individual APOE genotypes. METHODS: Participants underwent one baseline (t0), and 4 clinical and neuropsychological assessments (t1,t2,t3, and t4). Brain MRI was performed in all subjects at t0, t2, t3 and t4.. White matter hyperintensities were assessed through two visual rating scales. Lacunes were also rated. Subcortical and global brain atrophy were determined through the bicaudate ratio and the lateral ventricle to brain ratio, respectively. APOE genotypes were determined at t0 in all subjects. Cox proportional hazard model was used to evaluate the risk of progression to AD. RESULTS: The imaging class of mixed type was very common in AD, and in non amnestic mild cognitive impaired APOE ε4 non carriers. In these subjects, frontal and parieto-occipital regions were most affected by small vessel disease. CONCLUSION: Our findings suggest that the APOE ε3 allele is probably linked to the brain vascular pathology.

Refining the genetic structure and relationships of European cattle breeds through meta-analysis of worldwide genomic SNP data, focusing on Italian cattle.

The availability of genotyping assays has allowed the detailed evaluation of cattle genetic diversity worldwide. However, these comprehensive studies did not include some local European populations, including autochthonous Italian cattle. In this study, we assembled a large-scale, genome-wide dataset of single nucleotide polymorphisms scored in 3,283 individuals from 205 cattle populations worldwide to assess genome-wide autozygosity and understand better the genetic relationships among these populations. We prioritized European cattle, with a special focus on Italian breeds. Moderate differences in estimates of molecular inbreeding calculated from runs of homozygosity (FROH) were observed among domesticated bovid populations from different geographic areas, except for Bali cattle. Our findings indicated that some Italian breeds show the highest estimates of levels of molecular inbreeding among the cattle populations assessed in this study. Patterns of genetic differentiation, shared ancestry, and phylogenetic analysis all suggested the occurrence of gene flow, particularly among populations originating from the same geographical area. For European cattle, we observed a distribution along three main directions, reflecting the known history and formation of the analyzed breeds. The Italian breeds are split into two main groups, based on their historical origin and degree of conservation of ancestral genomic components. The results pinpointed that also Sicilian breeds, much alike Podolian derived-breeds, in the past experienced a similar non-European influence, with African and indicine introgression.

Genome-wide Analyses Identifies Known and New Markers Responsible of Chicken Plumage Color.

Through the development of the high-throughput genotyping arrays, molecular markers and genes related to phenotypic traits have been identified in livestock species. In poultry, plumage color is an important qualitative trait that can be used as phenotypic marker for breed identification. In order to assess sources of genetic variation related to the Polverara chicken breed plumage colour (black vs. white), we carried out a genome-wide association study (GWAS) and a genome-wide fixation index (FST) scan to uncover the genomic regions involved. A total of 37 animals (17 white and 20 black) were genotyped with the Affymetrix 600 K Chicken single nucleotide polymorphism (SNP) Array. The combination of results from GWAS and FST revealed a total of 40 significant markers distributed on GGA 01, 03, 08, 12 and 21, and located within or near known genes. In addition to the well-known TYR, other candidate genes have been identified in this study, such as GRM5, RAB38 and NOTCH2. All these genes could explain the difference between the two Polverara breeds. Therefore, this study provides the basis for further investigation of the genetic mechanisms involved in plumage color in chicken.

Genome-wide detection of signatures of selection in three Valdostana cattle populations.

The Valdostana is a local dual purpose cattle breed developed in Italy. Three populations are recognized within this breed, based on coat colour, production level, morphology and temperament: Valdostana Red Pied (VPR), Valdostana Black Pied (VPN) and Valdostana Chestnut (VCA). Here, we investigated putative genomic regions under selection among these three populations using the Bovine 50K SNP array by combining three different statistical methods based either on allele frequencies (FST ) or extended haplotype homozygosity (iHS and Rsb). In total, 8, 5 and 8 chromosomes harbouring 13, 13 and 16 genomic regions potentially under selection were identified by at least two approaches in VPR, VPN and VCA, respectively. Most of these candidate regions were population-specific but we found one common genomic region spanning 2.38 Mb on BTA06 which either overlaps or is located close to runs of homozygosity islands detected in the three populations. This region included inter alia two well-known genes: KDR, a well-established coat colour gene, and CLOCK, which plays a central role in positive regulation of inflammatory response and in the regulation of the mammalian circadian rhythm. The other candidate regions identified harboured genes associated mainly with milk and meat traits as well as genes involved in immune response/inflammation or associated with behavioural traits. This last category of genes was mainly identified in VCA, which is selected for fighting ability. Overall, our results provide, for the first time, a glimpse into regions of the genome targeted by selection in Valdostana cattle. Finally, this study illustrates the relevance of using multiple complementary approaches to identify genomic regions putatively under selection in livestock.

The Induced Smoothed lasso: A practical framework for hypothesis testing in high dimensional regression.

This paper focuses on hypothesis testing in lasso regression, when one is interested in judging statistical significance for the regression coefficients in the regression equation involving a lot of covariates. To get reliable p-values, we propose a new lasso-type estimator relying on the idea of induced smoothing which allows to obtain appropriate covariance matrix and Wald statistic relatively easily. Some simulation experiments reveal that our approach exhibits good performance when contrasted with the recent inferential tools in the lasso framework. Two real data analyses are presented to illustrate the proposed framework in practice.

Isolated, Subtle Neurological Abnormalities in Mild Cognitive Impairment Types.

BACKGROUND: Isolated, subtle neurological abnormalities (ISNA) are commonly seen in aging and have been related to cerebral small vessel disease (SVD) and subcortical atrophy in neurologically and cognitively healthy aging subjects. OBJECTIVE: To investigate the frequency of ISNA in different mild cognitive impairment (MCI) types and to evaluate for each MCI type, the cross-sectional relation between ISNA and white matter hyperintensities (WMH), lacunes, caudate atrophy, and ventricular enlargement. METHODS: One thousand two hundred fifty subjects with different MCI types were included in the analysis and underwent brain magnetic resonance imaging. WMHs were assessed through two visual rating scales. Lacunes were also rated. Atrophy of the caudate nuclei and ventricular enlargement were assessed through the bicaudate ratio (BCr) and the lateral ventricles to brain ratio (LVBr), respectively. Apolipoprotein E (APOE) genotypes were also assessed. The routine neurological examination was used to evaluate ISNAs that were clustered as central-based signs, cerebellar-based signs, and primitive reflexes. The items of Part-III of the Unified Parkinson's Disease Rating Scale were used to evaluate ISNAs that were clustered as mild parkinsonian signs. Associations of ISNAs with imaging findings were determined through logistic regression analysis. RESULTS: The ISNAs increase with the age and are present in all MCI types, particularly in those multiple domains, and carrying the APOE ϵ4 allele, and are associated with WMH, lacunes, BCr, and LVBr. CONCLUSION: This study demonstrates that cortical and subcortical vascular and atrophic processes contribute to ISNAs. Long prospective population-based studies are needed to disentangle the role of ISNAs in the conversion from MCI to dementia.

Des anomalies neurologiques subtiles et isolées associées à différents types de déficience cognitive légère. Contexte: Des anomalies neurologiques à la fois subtiles et isolées sont fréquemment observées chez les personnes vieillissantes. Elles ont été associées à la maladie des petits vaisseaux du cerveau (cerebral small vessel disease) et à une atrophie des structures sous-corticales chez des sujets âgés en santé sur les plans neurologique et cognitif. Objectif: Étudier la fréquence de ces anomalies dans le cas de différents types de déficience cognitive légère ; évaluer, pour chaque type de déficience, la relation transversale entre ces anomalies et des hyper-signaux de la substance blanche, des lacunes cérébrales, l'atrophie du noyau caudé et l'élargissement des ventricules. Méthodes: Au total, 1250 sujets atteints de différents types de déficience cognitive légère ont été inclus dans notre analyse et ont passé un examen d'IRM du cerveau. On a évalué les hyper-signaux de la substance blanche à l'aide de deux échelles d'évaluation visuelle. À noter que les lacunes cérébrales ont également été évaluées. Du côté de l'atrophie du noyau caudé et de l'élargissement des ventricules, ces anomalies ont été mesurées respectivement au moyen de l'index bicaudé (bicaudate ratio) et du ratio volumique ventricule-cerveau (lateral ventricles to brain ratio). Enfin, les génotypes associés à l'apolipoprotéine E (ApoE) ont été examinés. Fait à souligner, des examens neurologiques de routine portant sur les signes du système nerveux central, sur les signes du cervelet et sur les réflexes archaïques ont été utilisés pour tenter de cerner les anomalies évoquées ci-dessus. Des éléments de la partie III de l'échelle UPDRS (Unified Parkinson's Disease Rating Scale) ont été par ailleurs mis à profit pour évaluer les anomalies regroupées au sein de la catégorie des signes bénins de la maladie de Parkinson. Les liens entre ces anomalies et les résultats aux examens d'IRM ont été déterminés à l'aide d'une analyse de régression logistique. Résultats: Ces anomalies neurologiques à la fois subtiles et isolées augmentent en fonction de l'âge et sont présentes parmi tous les types de déficience cognitive légère, en particulier dans ces domaines multiples et chez les sujets porteurs de l'allèle ϵ4 du gène de l'ApoE. On a vu également qu'elles sont associées à des hyper-signaux de la substance blanche, à des lacunes cérébrales, à l'atrophie du noyau caudé et à l'élargissement des ventricules. Conclusion: Cette étude démontre que les processus vasculaires et atrophiques des structures corticales et sous-corticales contribuent à l'apparition d'anomalies neurologiques à la fois subtiles et isolées. Des études prospectives de longue haleine basées sur la population sont toutefois nécessaires pour mieux comprendre le rôle de ces anomalies dans l'évolution des cas de déficience cognitive légère vers la démence.

Mild Parkinsonian Signs in a Hospital-based Cohort of Mild Cognitive Impairment Types: A Cross-sectional Study.

BACKGROUND: Mild Parkinsonian Signs (MPS) have been associated with Mild Cognitive Impairment (MCI) types with conflicting results. OBJECTIVE: To investigate the association of individual MPS with different MCI types using logistic ridge regression analysis, and to evaluate for each MCI type, the association of MPS with caudate atrophy, global cerebral atrophy, and the topographical location of White Matter Hyperintensities (WMH), and lacunes. METHODS: A cross-sectional study was performed among 1,168 subjects with different types of MCI aged 45-97 (70,52 ± 9,41) years, who underwent brain MRI. WMH were assessed through two visual rating scales. The number and location of lacunes were also rated. Atrophy of the caudate nuclei and global cerebral atrophy were assessed through the bicaudate ratio, and the lateral ventricles to brain ratio, respectively. Apolipoprotein E (APOE) genotypes were also assessed. Using the items of the motor section of the Unified Parkinson's Disease Rating Scale, tremor, rigidity, bradykinesia, and gait/balance/axial dysfunction were evaluated. RESULTS: Bradykinesia, and gait/balance/axial dysfunction were the MPS more frequently encountered followed by rigidity, and tremor. MPS were present in both amnestic and non-amnestic MCI types, and were associated with WMH, lacunes, bicaudate ratio, and lateral ventricles to brain ratio. CONCLUSION: MPS are present in both amnestic and non-amnestic MCI types, particularly in those multiple domain, and carrying the APOE ε4 allele. Cortical and subcortical vascular and atrophic processes contribute to MPS. Long prospective studies are needed to disentangle the contribution of MPS to the conversion from MCI to dementia.

Combined approaches to identify genomic regions involved in phenotypic differentiation between low divergent breeds: Application in Sardinian sheep populations.

Selective breeding has led to modifications in the genome of many livestock breeds. In this study, we identified the genomic regions that may explain some of the phenotypic differences between two closely related breeds from Sardinia. A total of 44 animals, 20 Sardinian Ancestral Black (SAB) and 24 Sardinian White (SW), were genotyped using the Illumina Ovine 50K array. A total of 68, 38 and 15 significant markers were identified using the case-control genome-wide association study (GWAS), the Bayesian population differentiation analysis (FST ) and the Rsb metric, respectively. Comparisons among the approaches revealed a total of 22 overlapping markers between GWAS and FST and one marker between GWAS and Rsb. Three markers detected by Rsb were also located near (<2 Mb) to highly significant regions identified by GWAS and FST analyses. Moreover, one candidate marker identified by GWAS and FST approaches was located in a run of homozygosity island that was shared by both breeds. We identified several genes involved in many phenotypic differences (such as stature and growth, reproduction, ear size, coat colour, behaviour) between the two analysed breeds. This study shows that combining several genome-wide approaches could improve discovery of regions involved in the variability of breeding traits and responsible for the phenotypic diversity even between closely related breeds. Overall, the combination of such genome-wide methods can be extended to other livestock breeds that share between them a similar genetic background, to understand the process that shapes the patterns of genetic variability between closely related populations.

Genome-wide association study between CNVs and milk production traits in Valle del Belice sheep.

Copy number variation (CNV) is a major source of genomic structural variation. The aim of this study was to detect genomic CNV regions (CNVR) in Valle del Belice dairy sheep population and to identify those affecting milk production traits. The GO analysis identified possible candidate genes and pathways related to the selected traits. We identified CNVs in 416 individuals genotyped using the Illumina OvineSNP50 BeadChip array. The CNV association using a correlation-trend test model was examined with the Golden Helix SVS 8.7.0 tool. Significant CNVs were detected when their adjusted p-value was <0.01 after false discovery rate (FDR) correction. We identified 7,208 CNVs, which gave 365 CNVRs after aggregating overlapping CNVs. Thirty-one CNVRs were significantly associated with one or more traits included in the analysis. All CNVRs, except those on OAR19, overlapped with quantitative trait loci (QTL), even if they were not directly related to the traits of interest. A total of 222 genes were annotated within the significantly associated CNVRs, most of which played important roles in biological processes related to milk production and health-related traits. Identification of the genes in the CNVRs associated with the studied traits will provide the basis for further investigation of their role in the metabolic pathways related to milk production and health traits.

Nociceptive Primitive Reflexes in Neurologically and Cognitively Healthy Aging Subjects.

BACKGROUND: To assess the prevalence of three nociceptive primitive reflexes (nPR), i.e., glabellar tap, snout reflex, and palmomental reflex, in neurologically and cognitively healthy (NCH) aging subjects. OBJECTIVE: To investigate whether nPR are cross-sectionally associated with white matter hyperintensities (WMH), lacunes, atrophy of the caudate nuclei, and global brain atrophy. METHODS: A total of 1246 NCH subjects aged 45-91 years were included in the study and underwent standard brain MRI. Atrophy of the caudate nuclei and global brain atrophy were assessed through the bicaudate ratio (BCr) and lateral ventricles to brain ratio (LVBr), respectively. WMH were assessed through visual rating scales. Lacunes were also rated. Association of nPR with vascular risk factors/diseases and imaging findings was evaluated using logistic regression analysis. RESULTS: nPR were exhibited by 33.1% of subjects and increased with age. Subjects with nPR performed less than subjects without nPR in tests evaluating global cognition, executive functions, attention, and language. Snout reflex was the most common nPR, followed by glabellar tap and palmomental reflex. Glabellar tap was associated with parieto-temporal WMH, BCr, and LVBr; snout reflex was associated with frontal lacunes, temporal WMH, BCr, and LVBr; palmomental reflex was associated with parieto-occipital WMH, basal ganglia lacunes, BCr, and LVBr. CONCLUSIONS: This study demonstrates that in NCH aging individuals, nPR are associated with WMH, lacunes, BCr, and LVBr and are probably a warning sign of incipient cognitive decline. Therefore, NCH subjects presenting nPR should manage their vascular risk factors/vascular diseases rigorously in order to prevent or delay progression of small vessel disease, and future neurological and cognitive disabilities.

An association analysis to identify genetic variants linked to asthma and rhino-conjunctivitis in a cohort of Sicilian children.

Asthma and rhino-conjunctivitis are common chronic diseases in childhood. In this cross-sectional study, we performed a gene association analysis with current asthma and rhino-conjunctivitis in a cohort of Sicilian children aged 10-15 years. Overall, our findings reveal the importance of different genetic variants at 4p14, 16p12.1, 17q12, 6p12.2 and 17q21.1, identifying possible candidate genes responsible for susceptibility to asthma and rhino-conjunctivitis.

Association Between Atrophy of the Caudate Nuclei, Global Brain Atrophy, Cerebral Small Vessel Disease and Mild Parkinsonian Signs in Neurologically and Cognitively Healthy Subjects Aged 45-84 Years: A Crosssectional Study.

BACKGROUND: Mild Parkinsonian signs (MPS) are commonly seen in aging, and have been related to cerebral Small Vessel Diseases (SVD) with no univocal results. OBJECTIVE: The aim of this study was to investigate the cross-sectional relation between MPS and White Matter Hyperintensities (WMH), lacunes, caudate atrophy, and global cerebral atrophy in a large cohort of Neurologically and Cognitively Healthy (NCH) aging individuals. METHOD: 1,219 NCH individuals were included in the analysis, and underwent standard brain MRI. The items of the motor section of the Unified Parkinson's Disease Rating Scale were used to evaluate tremor, rigidity, bradykinesia, and gait/balance/axial dysfunction. Caudate atrophy and global cerebral atrophy were assessed through the bicaudate ratio and the lateral ventricles to brain ratio, respectively. WMH were assessed through two visual rating scales. Lacunes were also rated. Associations of MPS with vascular risk factors/diseases and imaging findings were determined through the logistic regression analysis. RESULTS: Frontal and basal ganglia lacunes, frontal WMH, caudate atrophy, and global cerebral atrophy were associated with bradykinesia. Basal ganglia lacunes, caudate atrophy, and global cerebral atrophy were associated with gait/balance/axial dysfunction. Rigidity was associated with frontal WMH, and tremor with caudate atrophy and global cerebral atrophy. NCH subjects with MPS, performed less than subjects without MPS in tests evaluating global cognition and language. CONCLUSION: This study demonstrates that in NCH aging individuals, MPS are associated with cortical and subcortical vascular and atrophic changes, and are probably, a warning sign of incipient cognitive decline. Subjects with MPS should manage rigorously cerebral SVD to prevent future physical and cognitive disabilities.

Genome-wide scan for runs of homozygosity identifies potential candidate genes associated with local adaptation in Valle del Belice sheep.

BACKGROUND: Because very large numbers of single nucleotide polymorphisms (SNPs) are now available throughout the genome, they are particularly suitable for the detection of genomic regions where a reduction in heterozygosity has occurred and they offer new opportunities to improve the accuracy of inbreeding ([Formula: see text]) estimates. Runs of homozygosity (ROH) are contiguous lengths of homozygous segments of the genome where the two haplotypes inherited from the parents are identical. Here, we investigated the occurrence and distribution of ROH using a medium-dense SNP panel to characterize autozygosity in 516 Valle del Belice sheep and to identify the genomic regions with high ROH frequencies. RESULTS: We identified 11,629 ROH and all individuals displayed at least one ROH longer than 1 Mb. The mean value of [Formula: see text] estimated from ROH longer than1 Mb was 0.084 ± 0.061. ROH that were shorter than 10 Mb predominated. The highest and lowest coverages of Ovis aries chromosomes (OAR) by ROH were on OAR24 and OAR1, respectively. The number of ROH per chromosome length displayed a specific pattern, with higher values for the first three chromosomes. Both number of ROH and length of the genome covered by ROH varied considerably between animals. Two hundred and thirty-nine SNPs were considered as candidate markers that may be under directional selection and we identified 107 potential candidate genes. Six genomic regions located on six chromosomes, corresponding to ROH islands, are presented as hotspots of autozygosity, which frequently coincided with regions of medium recombination rate. According to the KEGG database, most of these genes were involved in multiple signaling and signal transduction pathways in a wide variety of cellular and biochemical processes. A genome scan revealed the presence of ROH islands in genomic regions that harbor candidate genes for selection in response to environmental stress and which underlie local adaptation. CONCLUSIONS: These results suggest that natural selection has, at least partially, a role in shaping the genome of Valle del Belice sheep and that ROH in the ovine genome may help to detect genomic regions involved in the determinism of traits under selection.