Analysis of uniparental markers reveals a complex pattern of migration within Sardinia.

BACKGROUND: From the genetic viewpoint, Sardinia is well differentiated from other surrounding populations. In spite of a common ancestral origin, substantial genetic heterogeneity is observed within the island. Matrimonial pattern, as well as past migration movements, may account for the complex genetic structure of Sardinia. AIM: To compare data from uniparental markers in order to highlight the migration pattern of male and female lineages and check their congruence with the demographic data. SUBJECTS AND METHODS: Genomic DNA was obtained from 279 unrelated males selected from three isolated villages and from three open populations representative of North, Central and South Sardinia. The hypervariable region 1 of mtDNA was sequenced and 17 Y-chromosome loci were genotyped. Parameters of within and among populations diversity were calculated and analysis of migration was performed. RESULTS: When analysed as a whole population, demographic data show a balanced movement of males and females in Sardinia, unlike other Italian and European populations. Remarkably, when the island is divided into geographic areas, different migration patterns are clearly recognisable. Whereas North and Central Sardinia populations show a stronger male migration rate, the South Sardinia population shows a stronger female migration rate. CONCLUSION: Distinct migration patterns of male and female lineages affect the areas investigated differently. These past migration movements are major contributors to the complex genetic structure currently observed in the Sardinian population.

Association Between MCT1 A1470T Polymorphism and Fat-Free Mass in Well-Trained Young Soccer Players.

The aim of this study was to investigate the association between the MCT1 A1470T polymorphism and fat-free mass in young Italian elite soccer players. Participants were 128 Italian male soccer players. Fat-free mass was estimated for each of the soccer player using age- and gender-specific formulas with plicometry. Genotyping for the MCT1 A1470T polymorphism was performed using polymerase chain reaction. The MCT1 A1470T genotypes were in agreement with the Hardy-Weinberg equilibrium distribution. The percentage of fat-free mass was significantly higher in soccer players with the TT genotype and in the T-allele-dominant model group (TT + AT) compared with the soccer players with the AA genotype. The MCT1 T allele is associated with the percentage of fat-free mass in young elite male soccer players. Elucidating the genetic basis of body composition in athletes could potentially be used as an additional tool for strength and conditioning professionals in planning and adjusting training. However, these results are preliminary and need to be replicated in more cohorts.

Analysis of 16 STRs of NOS gene regions and around in six Sardinian populations (Italy).

OBJECTIVES: The aims of this work are to provide first data on novel STRs at the NOS gene regions in human populations and to test for possible correlations with mortality rate by malaria in different areas of Sardinia (Italy). METHODS: In the present study, 16 STRs (13 analyzed for the first time in human populations) localized on three genes NOS were typed in 213 healthy individuals, unrelated for at least three generations, from six historical-geographical Sardinian areas. STRs alleles were determined through sequencing. Statistical analyses were performed by Genepop (v.4.0), Arlequin (v.3.5.1.2), R (v.2.15.1), Statistica (v.5.1), and PHASE (v.2.1) software packages. RESULTS: The number of alleles found for each locus ranged from 2 to 12 and their distribution is most often unimodal. All populations met Hardy Weinberg equilibrium after Bonferroni correction, with few exceptions. Analysis of genetic distances did not show strong genetic structuring of the investigated populations. Instead, the population genetic variability shows a positive and highly significant (P-value < 0.01) correlation between mortality determined by malaria infection and alleles (TGGA)7 of NOS2, (AAAAG)2 and (ATTT)10 of adNOS1, and (AAACA)11 of adNOS3 genes. CONCLUSIONS: The peculiar allele distribution found for several NOS alleles could be due to malaria infection that may have contributed to their frequencies, but we cannot exclude that the peculiar allele distribution of NOS might also be due to genetic drift, emphasized by isolation and founder effect.

Sampling strategies in a linguistic isolate: results from mtDNA analysis.

OBJECTIVES: Sampling strategies are crucial issues in population genetics and anthropological studies. The sampling choice is related to the research question and the type of markers used. In this research, we compared two different sampling strategies in the Sardinian linguistic isolate of Carloforte (Italy). METHODS: A first sampling (N = 49) was carried out through grandparents criterion: individuals selected for the study were born and resident in Carloforte, and unrelated for at least three generations. A second sampling (N = 50) was based on founders surnames (FS): selected participants were proved to be descendants of the village founders, and to have no ancestors in common, at least up to the grandparental generation. RESULTS: The group selected through FS showed a greater gene diversity, which was confirmed by both network and haplogroup analysis. Among the shared haplogroups, we find clear differences in their frequencies. Sampling through grandparents criterion showed essentially the same haplogroups found in Sardinia, and with similar frequencies. Interesting results came from genetic tree. The FS sampling clustered with Northern African populations and it is located very far from Italian and Sardinian populations, whereas the grandparents criterion sampling clustered with Italian populations and it is located close to the other Sardinian populations. CONCLUSIONS: Results showed that different sampling strategies can lead to contrasting results. As sampling through grandparents criterion is influenced by recent gene flow, we hypothesize that the difference observed with the two sampling strategies is due to the merging of Carloforte with Sardinian populations.

Vitamin D receptor gene polymorphisms and musculoskeletal injuries in professional football players.

The aim of the present study was to investigate the association between vitamin D receptor (VDR) gene polymorphisms and musculoskeletal injury (MI) in elite football players. In total, 54 male professional football players were recruited from an official Italian professional championship team between 2009 and 2013. The cohort was genotyped for the ApaI, BsmI and FokI polymorphisms and MI data were collected over four football seasons. No significant differences were identified among the genotypes in the incidence rates or severity of MI (P=0.254). In addition, no significant associations were observed between VDR polymorphisms and MI phenotypes (P=0.460). However, the results of the casewise multiple regression analysis indicated that the ApaI genotypes accounted for 18% of injury severity (P=0.002). Therefore, while the BsmI and FokI polymorphisms did not appear to be associated with the severity or incidence of MI, the ApaI genotypes may have influenced the severity of muscle injury in top-level football players.

Influence of the MCT1 rs1049434 on Indirect Muscle Disorders/Injuries in Elite Football Players.

BACKGROUND: The aim of this study was to investigate the association between MCT1 rs1049434 polymorphism and indirect muscle injuries in elite football players. One hundred and seventy-three male elite Italian football players (age = 19.2 ± 5.3 years) were recruited from a first-league football club participating at the Official National Italian Football Championship (Serie A, Primavera, Allievi, Giovanissimi). The cohort was genotyped for the MCT1 rs1049434 polymorphism, and muscle injuries data were collected during the period of 2009-2014 (five football seasons). METHODS: Genomic DNA was extracted using a buccal swab, and genotyping was performed using PCR method. Structural-mechanical injuries and functional muscle disorder were included in the acute indirect muscle injury group. RESULTS: Participants with the MCT1 AA (AA = 1.57 ± 3.07, n = 69) genotype exhibit significantly higher injury incidents compared to participants with the TT genotype (TT = 0.09 ± 0.25, n = 22, P = 0.04). CONCLUSIONS: The MCT1 rs1049434 polymorphism is associated with the incidence of muscle injuries in elite football players. We anticipate that the knowledge of athletes' genetic predisposition to sports-related injuries might aid in individualizing training programs.

ACTN3 R577X polymorphism is not associated with team sport athletic status in Italians.

BACKGROUND: The ACTN3 gene may influence performance in team sports, in which sprint action and high-speed movements, regulated by the anaerobic energy system, are crucial to the ultimate success of a match. The aim of this study was to determine the association between the ACTN3 R577X (rs1815739) polymorphism and elite team sport athletic status in Italian male athletes. METHODS: We compared the genotype and allele frequency of the ACTN3 R577X polymorphism between team sport athletes (n = 75), endurance athletes (n = 40), sprint/power athletes (n = 64), and non-athletic healthy controls (n = 192) from Italy. Genomic DNA was collected using a buccal swab. Extraction was performed according to the manufacturer's directions provided with a commercially available kit (Qiagen S.r.l., Milan, Italy). RESULTS: Team sport athletes showed a lower frequency of the 577RR genotype compared to the 577XX genotype than sprint/power athletes (p = 0.044). However, the ACTN3 R577X polymorphism was not associated with team sport athletic status compared to endurance athletes and non-athletic controls. CONCLUSIONS: Our results agree with a recent large-scale study involving athletes from Spain, Poland, and Russia. The ACTN3 R577X polymorphism was not associated with team sport athletic status compared to endurance athletes and non-athletic controls.

Linguistic, geographic and genetic isolation: a collaborative study of Italian populations.

The animal and plant biodiversity of the Italian territory is known to be one of the richest in the Mediterranean basin and Europe as a whole, but does the genetic diversity of extant human populations show a comparable pattern? According to a number of studies, the genetic structure of Italian populations retains the signatures of complex peopling processes which took place from the Paleolithic to modern era. Although the observed patterns highlight a remarkable degree of genetic heterogeneity, they do not, however, take into account an important source of variation. In fact, Italy is home to numerous ethnolinguistic minorities which have yet to be studied systematically. Due to their difference in geographical origin and demographic history, such groups not only signal the cultural and social diversity of our country, but they are also potential contributors to its bio-anthropological heterogeneity. To fill this gap, research groups from four Italian Universities (Bologna, Cagliari, Pisa and Roma Sapienza) started a collaborative study in 2007, which was funded by the Italian Ministry of Education, University and Research and received partial support by the Istituto Italiano di Antropologia. In this paper, we present an account of the results obtained in the course of this initiative. Four case-studies relative to linguistic minorities from the Eastern Alps, Sardinia, Apennines and Southern Italy are first described and discussed, focusing on their micro-evolutionary and anthropological implications. Thereafter, we present the results of a systematic analysis of the relations between linguistic, geographic and genetic isolation. Integrating the data obtained in the course of the long-term study with literature and unpublished results on Italian populations, we show that a combination of linguistic and geographic factors is probably responsible for the presence of the most robust signatures of genetic isolation. Finally, we evaluate the magnitude of the diversity of Italian populations in the European context. The human genetic diversity of our country was found to be greater than observed throughout the continent at short (0-200 km) and intermediate (700-800km) distances, and accounted for most of the highest values of genetic distances observed at all geographic ranges. Interestingly, an important contribution to this pattern comes from the "linguistic islands"( e.g. German speaking groups of Sappada and Luserna from the Eastern Italian Alps), further proof of the importance of considering social and cultural factors when studying human genetic variation.