Search results for " genetic variability."
showing 5 items of 15 documents
Population structure in the Méditerranean basin: a Y chromosome perspective
2006
The Mediterranean region has been characterised by a number of pre-historical and historical demographic events whose legacy on the current genetic landscape is still a matter of debate. In order to investigate the degree of population structure across the Mediterranean, we have investigated Y chromosome variation in a large dataset of Mediterranean populations, 11 of which are first described here. Our analyses identify four main clusters in the Mediterranean that can be labelled as North Africa, Arab, Central-East and West Mediterranean. In particular, Near Eastern samples tend to separate according to the presence of Arab Y chromosome lineages, suggesting that the Arab expansion played a…
Complete sequence, genotyping and comparative analysis of Pepino mosaic virus discovered isolates from Italy
2011
Pepino mosaic virus (PepMV) causes economic damage to the tomato industry worldwide. In Italy, the virus is endemic in Sicily, an important tomato-production region, and a new outbreak has been recorded in Sardinia after the first PepMV appearance in 2001. Italian PepMV isolates from these two geographically distant regions were molecularly characterized and the complete nucleotide sequence of four isolates was determined by walking primer strategy. The complete nucleotide and deduced amino acid sequences were analyzed and compared with published PepMV sequences. Italian isolates belong to the PepMV-Ch2 strain and had 97.2% to 98.5% identity with those of the reference PepMV-Ch2 deposited i…
Genetic diversity on Pyrus L. (Rosaceae) in Sicily
2009
The genetic diversity on six Pyrus species (P. amygdaliformis, P. pyraster, P. communis, P. vallis- demonis, P. sicanorum, P. castribonensis) from Sicily was investigated using isozymes. Atotal of 26 alleles was found in 8 loci of 5 enzyme systems (IDH,MDH, 6-PGD, PGI and SKD). The allelic frequencies and the genetic variability values for each population were calculated. The greatest rate of polymorphism was found in P. sicanorum, P. castribonensis and P. amygdaliformis from Sicani Mts. The relationships among the populations were computed by Nei’s genetic identity/distance and the obtained dendrogram shows a remarkable genetic distance of P. vallis-demonis from of all other investigated t…
SNP variation in the bitter taste TAS2R38 gene evaluated in student populations of several italian universities and isolates
2007
People vary widely in their sensitivities to bitter compounds, but the all intercorrelation of these sensitivities is unknown. The study of genetic influences on bitter taste perception originated from the discovery in the 1930s that some individuals had taste to phenylthiocarbamide(PTC), whereas others found it extremely bitter. Subsequently, many studies were carried out on PTC and the structurally related compound propylthiouracil (PROP) to assess this viability and to determine the root causes. Initial family studies strongly suggested that PTC no tasting was due to a recessive allele in a single gene and heritability was estimated at 0,5. 55-85% of variation in PTC detection. The PTC ge…