Biomedical subjects

F Calafell

Publications and source records attributed to F Calafell.

81 records · Page 5Linked to original sources

PubMed1995

Do Basque- and Caucasian-speaking populations share non-Indo-European ancestors?

Genetic evidence is consistent with the view that the Indo-European languages were propagated in Europe by the diffusion of early farmers. The existence of phylogenetic relationships between European populations speaking other languages has been proposed on linguistic and archaeological grounds, and is here tested by analyzing allele frequencies at ten polymorphic protein and blood group loci. Genetic distances between speakers of Basque and Caucasian languages are compared with those between controls, i.e. contiguous populations speaking Indo-European and Altaic. Although some statistical tests show an excess of genetic similarity between Basque and South Caucasian speakers, most results do not support their common origin. If the Basques and the Caucasian-speaking populations share common ancestors, recent evolutionary phenomena must have caused divergence between them, so that their gene frequencies do not appear more similar now than those of random pairs of populations separated by the same geographic distance.

Biological Evolution↗

PubMed1994

Principal component analysis of gene frequencies and the origin of Basques.

The genetic peculiarity of the Basque population has long been noted. We aim to describe Basque distinctiveness in space and assess the internal Basque heterogeneity. All these aspects are relevant to the question of the origin of Basques. After a thorough literature search, a data base was created containing all the available data on gene frequencies in the Iberian Peninsula and France. Twenty-nine systems, comprising 71 alleles, were used to carry out a principal component (PC) analysis. The results show a sharp peak in the first PC in the Basque area, which remains even when the geographic scope is widened to include western Europe. As demonstrated by "wombling" analysis, the steeper slope in the first PC is found to the east of the Basque area, along the Pyrenees. Measures of genetic heterogeneity (such as FST values) within the Basque country, as compared to those for non-Basques, do not show a particular internal substructuration in the Basque population. The genetic results support a scenario in which the Basques are the product of in situ differentiation around the time of the Last Glacial Maximum (18,000 B.P.), in agreement with archaeological and linguistic data. Isolation from the surrounding populations has allowed the differentiation to last for millennia, but has erased the differences existing among Basques.

Alleles↗

PubMed1994

Mountains and genes: population history of the Pyrenees.

The Pyrenees Mountains rise between France and Spain. At their western end live the Basques, one of the oldest populations in Europe. All the available genetic information (gene frequencies of blood groups, serum proteins, red cell enzymes, and HLA antigens) on Pyrenean populations has been gathered and subjected to two kinds of analysis: a discrete approach, in which eight separate populations have been defined according to linguistic and geographic criteria to compute genetic distances between them; and a continuous principal components analysis on gene frequencies interpolated to a regular grid. In the first approach the Pyrenean samples have also been compared to other Western European populations. Our results show that the Basque population is most genetically differentiated with respect to other Pyrenean and Western European populations. There is a strong genetic gradient along the mountain range (i.e., in an east-west direction); thus the mountains have not acted as barriers to gene flow. A Catalan-speaking sample, the Cerdanya, is slightly detached from its neighbors and seems closer to other European populations. This genetic picture together with linguistic, paleoanthropological, and archeological data points to a Mesolithic (or older) differentiation of the Cantabrian ancestors of the Basques. Moreover, the Basque genetic features are found in the northern slope of the Pyrenees far beyond the present Basque linguistic boundaries, in accordance with the most recent hypotheses on Pyrenean historical linguistics. The genetic consequences of the arrival of the first Indo-European-speaking peoples in the Iberian Peninsula are also studied; no clear genetic trace has been left of that population movement, except perhaps for the Cerdanya, an eastern valley that affords a passage between north and south.

Algorithms↗

PubMed1993

Multivariate approach to matrimonial mobility in Catalonia.

Matrimonial mobility in Catalonia was studied using 1986 census data. Comarca (a geographic division) of birth was used as the population unit, and a measure of affinity (a statistical distance) between comarques in spouse geographic origin was defined. This distance was analyzed with multivariate methods drawn from numerical taxonomy to detect any discontinuities in matrimonial mobility and gene flow between comarques. Results show a three-level pattern of gene flow in Catalonia: (1) a strong endogamy within comarques; (2) a 100-km matrimonial circle around every comarca; and (3) the capital, Barcelona, which attracts migrants from all over Catalonia. The regionalization in matrimonial mobility follows the geographically clear-cut groups of comarques almost exactly.

Family↗

PubMedDate not supplied

Human mitochondrial DNA sequence variation in the Moroccan population of the Souss area.

BACKGROUND: Various populations have contributed to the present-day gene pool of Morocco, including the autochthonous Berber population, Phoenicians, Sephardic Jews, Bedouin Arabs and sub-Saharan Africans. OBJECTIVE: The primary objective of the study was to complete a genetic description of the Berber-speaking population in the Souss region of southern Morocco, based on mitochondrial DNA (mtDNA) sequence analysis. SUBJECTS AND METHODS: The first hypervariable segment of the mtDNA control region was sequenced in a sample of 50 individuals from the Souss Valley, and the results compared with the extensive body of data available on mtDNA sequence variation in Europe and sub-Saharan Africa. RESULTS: Thirty-four different sequences were found: an estimated 68% of the sequences occurred throughout Europe, West Asia and North Africa, 26% originated in sub-Saharan Africa, and 6% belonged to the North African specific haplogroup U6. The Souss Valley mtDNA sequences indicated the presence of two populations which expanded at different times: the West Eurasian sequences in the Souss sample had a smaller average number of pairwise differences than pairs of sub-Saharan sequences. CONCLUSION: Detailed knowledge of the possible geographic origin of each sequence facilitated an interpretation of both internal diversity parameters and between-population relationships. The sub-Saharan admixture in the Souss Valley matched the south-north cline of sub-Saharan influence in North Africa, also evident in the genetic distances of North African populations to Europeans and sub-Saharan Africans.

Africa South of the Sahara↗

PubMedDate not supplied

Population history of Corsica: a linguistic and genetic analysis.

Genetic and linguistic differentiations within Corsica were analysed and compared; the genetic relationships of Corsica to other Mediterranean populations were also studied. Lexical distances between 49 Corsican localities were computed from a standard word list; trees built from these distances were compared with average linkage and neighbour-joining trees of genetic distances. Our lexical distance results confirmed the north/south dialectal subdivision of Corsican speeches described by linguists. No clear results were achieved with genetic distances because of the low number of loci for which data were available. Nevertheless, a tight northern cluster clearly emerged. When compared to other Mediterranean populations, Corsica showed a certain degree of differentiation, although not so marked as that of Sardinia. Corsica presented genetic affinities with Campania, Sicily, Liguria, Provence and Latium, while distances with Tuscany and Sardinia were larger. These results can be interpreted as a reflection of the prehistoric isolation of Corsica and the relative contribution to the island gene pool of prehistoric and historic invaders and immigrants from several populations.

Blood Group Antigens↗

PubMedDate not supplied

Blood biochemistry reflects seasonal nutritional and reproductive constraints in the eurasian badger (Meles meles).

Physiological responses to nutritional and reproductive constraints were explored in a wild population of Eurasian badgers (Meles meles) inhabiting Wytham Woods, Oxfordshire, United Kingdom. We compared seasonal blood levels of lipid and protein compounds to variables describing the sex, age, body condition, wounds, testes position, and flea abundance of the badgers. We found seasonal variations in albumin/globulins and urea/creatinine ratios matched by differences in body condition. High creatinine, urea, and triglycerides levels were obtained in animals in poor nutritional condition and with low levels of body fat. The maintenance of urea/creatinine ratios indicates that the badger does not demonstrate a stage of protein conservation in periods of food scarcity during the summer or periods of cold weather. Hypercholesterolaemia, especially in fat animals, was confirmed. We also offer baseline levels of metabolites commonly used in clinical biochemistry for their further use in the analysis of the status and the management of wild badger populations.

Adipose Tissue↗

PubMedDate not supplied

Allele frequencies for 20 microsatellites in a worldwide population survey.

20 microsatellite polymorphisms: HUMHPRT, HUMD3S1358, HUMTH01, HUMACPP, HUMVWF, HUMD16S310, HUMD4S243, HUMTPO, HUMFES/FPS, HUMF13A1, HUMDHFRP2, HUMD11S2010, HUMD13S767, HUMD9S926, HUMD2S1328, HUMD14S306, HUMD18S848, HUMD5S818, HUMD7S820 and HUMFGA were analyzed in a worldwide survey covering five continents and allele frequencies are given. There is a high heterogeneity in allele frequencies among continents. A neighbor-joining tree based on Fst distance shows a pattern of differentiation that may reflect the role of drift in the development of genetic differences among humans. The variation found between continents confirms the usefulness of tetranucleotide microsatellites in human genetic variation studies.

Alleles↗

PubMedDate not supplied

Nicaraguan population data on LDLR, GYPA, D7S8, HBGG, GC and HLA-DQA1 loci.

Nicaraguans have become the most numerous and fastest increasing minority in Costa Rica: at present they represent around 6% of the total population of the country. We have analyzed the allele and genotype frequencies of six PCR-based genetic markers (LDLR, GYPA, HBGG, D7S8, GC, and HLA-DQA1) in 100 unrelated Nicaraguans living in Costa Rica. All loci studied were in Hardy-Weinberg equilibrium. Some statistical parameters of forensic interest were also calculated (h, PD and CE). Allele frequencies of the markers HLA-DQA1 and GYPA were found to be significantly different between the populations of Nicaragua and Costa Rica. Nevertheless, genetic distances showed that Nicaragua is close to other Hispanic-admixed populations like those from Argentina, Chile, Colombia, Costa Rica, and USA Hispanics. The loci set was assessed to be useful for paternity testing and individual identification in the Nicaraguan population residing in Costa Rica.

Adult↗