Laura Corrias

Polymorphisms in TAS2R38 and the taste bud trophic factor, gustin gene co-operate in modulating PROP taste phenotype

The PROP taste phenotype varies greatly among individuals, influencing eating behavior and therefore may play a role in body composition. This variation is associated with polymorphisms in the bitter receptor gene TAS2R38 and the taste-bud trophic factor gustin gene. The aim of this study was to examine the relationship between TAS2R38 haplotypes and the gustin gene polymorphism rs2274333 in modulating PROP taste phenotype. PROP phenotype was determined in seventy-six volunteers (29 males, 47 females, age 25±3 y) by scaling methods and threshold measurements. TAS2R38 and gustin gene genotyping was performed using PCR techniques. The lowest responsiveness in PROP nontasters is strongly associated with the AVI nontasting TAS2R38 variant and the highest responsiveness in supertasters is strongly associated to allele A and genotype AA of the gustin gene. These data support the hypothesis that the greater sensitivity of supertasters could be mediated by a greater taste-bud density. Polymorphisms in TAS2R38 and gustin gene, together, accounted for up to 60% of the phenotypic variance in PROP bitterness and to 40% in threshold values. These data, suggest that other unidentified factors may be more relevant for detecting low concentrations of PROP. Moreover, the presence of the PAV variant receptor may be important for detecting high concentrations of PROP, whereas the presence of allele A in gustin polymorphism may be relevant for perceiving low concentrations. These data show how the combination of the TAS2R38 and gustin gene genotypes modulate PROP phenotype, providing an additional tool for the evaluation of human eating behavior and nutritional status.

Genome-wide scan with nearly 700 000 SNPs in two Sardinian sub-populations suggests some regions as candidate targets for positive selection

This paper explores the genetic structure and signatures of natural selection in different sub-populations from the Island of Sardinia, exploiting information from nearly 700 000 autosomal SNPs genotyped with the Affymetrix Genome-Wide Human SNP 6.0 Array. The genetic structure of the Sardinian population and its position within the context of other Mediterranean and European human groups were investigated in depth by comparing our data with publicly available data sets. Principal components and admixture analyses suggest a clustering of the examined samples in two significantly differentiated sub-populations (Ogliastra and Southern Sardinia), as confirmed by AMOVA (FST=0.011; P<0.001). Differentiation of these sub-populations was still evident when they were pooled together with supplementary Sardinian samples from HGDP and compared with several other European, North-African and Near Eastern populations, confirming the uniqueness of the Sardinian genetic background. Moreover, by applying several statistical approaches aimed at assessing differences at the SNP level, the highest differentiated genomic regions between Ogliastra and Southern Sardinia were thus investigated via an extended haplotype homozygosity (EHH)-based test to point out potential selective sweeps. Using this approach, 40 genomic regions were detected, with significant differences between Ogliastra and Southern Sardinia. These regions were subsequently investigated using a long-range haplotype test, which found significant REHH values for SNPs rs11070188 and rs11070192 in the Ogliastra sub-population. In the light of these results and the overlap of the different computed statistics, the region encompassing these loci can be considered a strong candidate to have undergone selective pressure in Ogliastra.

Sampling strategies in a linguistic isolate: Results from mtDNA analysis

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).

Non-random distribution of 17 Y-chromosome STR loci in different areas of Sardinia

Allele frequencies of 17 Y-chromosome short tandem repeat (STR) loci, included in the AmpFlSTR® Y-FilerTM amplification kit, were analyzed for the first time in different samplings (N=268) from Sardinia, Italy. Samples were collected from three isolated populations (N=139) and three open populations (N=129). A total of 230 unique haplotypes were detected; the observed haplotype diversity and discrimination capacity were 0.998 and 0.858, respectively. The data presented confirm that Sardinian population is well differentiated from other Italian and Mediterranean populations. Although regarded as a homogeneous population, substantial heterogeneity was detected when Sardinian isolated villages or microareas were analyzed. Our results highlights the importance of building a Sardinia-own database, organized by small areas, as a powerful tool for both forensic applications and population genetics studies.

ACTN-3 and ACE genotypes in elite male Italian athletes

Abstract The ACE I/D and the ACTN-3 R577X polymorphisms are the most studied genes associated with elite athlete status, even if this association has been often conflicting. The aim of the present study was to investigate the association between the ACE and the ACTN3 genotypes and elite performance in Italian male athletes. The ACTN-3 R577X and the ACE I/D genotype distributions of 59 elite male Italian athletes practicing gymnastics (G; n = 17), 100 m-400 m running (R; n = 12), and playing soccer (S; n= 30) were compared with controls from Italian (C; n = 31) populations. For ACE distribution, athletes did not differ from controls (G, χ2 = 0.37, df = 2, p = 0.82; R, χ2 = 1.90, df = 2, p = 0.45; S, χ2 = 1.48, df = 2, p = 0.47) and the DD genotype was at very high frequency in all groups (G = 53%, R= 50%, S = 60%, C = 45%). For ACTN-3 distribution, elite gymnasts showed a significant difference from controls (χ2 = 6.57, df = 2, p = 0.03), showing an absence of XX genotype. Soccer players and runners did not differ from controls in ACTN-3 genotype distribution (R, χ2 =0.43, df = 2, p = 0.80; S, χ2 = 1.25, df = 2, p = 0.53). Even if the ACE DD genotype is often positively associated with elite sprint/power athlete status, its high frequency in Italian populations eliminates the possibility of its exclusive association in Italian athletes. The results of ACTN3 genotypes suggest that RR genotype of ACTN-3 gene is a determinant of elite gymnasts status but it is not the key factor for achieving a top-level performance in soccer or track events.

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

BackgroundThe 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.MethodsWe 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).ResultsTeam 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.ConclusionsOur 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.

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

Abstract Massidda, M, Eynon, N, Bachis, V, Corrias, L, Culigioni, C, Cugia, P, Scorcu, M, and Calò, CM. Association between MCT1 A1470T polymorphism and fat-free mass in well-trained young soccer players. J Strength Cond Res 30(4): 1171–1176, 2016—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).

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).