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E Mateu

Publications and source records attributed to E Mateu.

At least 37 records · Page 2Linked to original sources
PubMed2001

Why is anti-microbial resistance a veterinary problem as well?

Resistance to anti-microbial agents has become one of the main issues in public health strategies world-wide. Much attention has been paid to the emergence of pathogenic micro-organisms such as enterococci or Salmonella that have developed resistance mechanisms that render them almost untreatable with current antibiotics. One of the alleged reasons for such an emergence is the non-medical use of antibiotics, especially in animals. However, only recently have veterinary forums and journals begun to discuss this topic. On the other hand, anti-microbial resistance has also become a problem in veterinary medicine and the number of reports indicating high rates of resistance among animal-originated micro-organisms is considerable. The present review deals with the mechanisms of resistance known for antibiotics in common veterinary use, the problem of anti-microbial resistance in veterinary medicine and the links between the use of antibiotics in animals and the emergence of anti-microbial resistance in humans.

Animals↗
PubMed2001

Sequence variability of a human pseudogene.

We have obtained haplotypes from the autosomal glucocerebrosidase pseudogene (psGBA) for 100 human chromosomes from worldwide populations, as well as for four chimpanzee and four gorilla chromosomes. In humans, in a 5420-nucleotide stretch analyzed, variation comprises 17 substitutions, a 3-bp deletion, and a length polymorphism at a polyadenine tract. The substitution rate on the pseudogene (1.23 +/- 0.22 x 10(-9) per nucleotide and year) is within the range of previous estimates considering phylogenetic estimations. Recombination within the pseudogene was recognized, although the low variability of this locus prevented an accurate measure of recombination rates. At least 13% of the psGBA sequence could be attributed to gene conversion from the contiguous GBA gene, whereas the reciprocal event has been shown to lead to Gaucher disease. Human psGBA sequences showed a recent coalescence time (approximately 200,000 yr ago), and the most ancestral haplotype was found only in Africans; both observations are compatible with the replacement hypothesis of human origins. In a deeper timeframe, phylogenetic analysis showed that the duplication event that created psGBA could be dated at approximately 27 million years ago, in agreement with previous estimates.

Animals↗
PubMed2000

Worldwide genetic analysis of the CFTR region.

Mutations at the cystic fibrosis transmembrane conductance regulator gene (CFTR) cause cystic fibrosis, the most prevalent severe genetic disorder in individuals of European descent. We have analyzed normal allele and haplotype variation at four short tandem repeat polymorphisms (STRPs) and two single-nucleotide polymorphisms (SNPs) in CFTR in 18 worldwide population samples, comprising a total of 1,944 chromosomes. The rooted phylogeny of the SNP haplotypes was established by typing ape samples. STRP variation within SNP haplotype backgrounds was highest in most ancestral haplotypes-although, when STRP allele sizes were taken into account, differences among haplotypes became smaller. Haplotype background determines STRP diversity to a greater extent than populations do, which indicates that haplotype backgrounds are older than populations. Heterogeneity among STRPs can be understood as the outcome of differences in mutation rate and pattern. STRP sites had higher heterozygosities in Africans, although, when whole haplotypes were considered, no significant differences remained. Linkage disequilibrium (LD) shows a complex pattern not easily related to physical distance. The analysis of the fraction of possible different haplotypes not found may circumvent some of the methodological difficulties of LD measure. LD analysis showed a positive correlation with locus polymorphism, which could partly explain the unusual pattern of similar LD between Africans and non-Africans. The low values found in non-Africans may imply that the size of the modern human population that emerged "Out of Africa" may be larger than what previous LD studies suggested.

Africa↗
PubMed2000

Allele frequencies of 13 short tandem repeats in population samples from the Iberian Peninsula and northern Africa.

The 13 short tandem repeat (STR) loci D3S1358, vWA, FGA, D16S539, TH01, TPOX, CSF1PO, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820 as well as the amelogenin locus, contained in AmpFlSTR Profiler Plus and/or AmpFlSTR Cofiler and/or AmpFlSTR Green I PCR amplification kits, were studied in four populations from the Iberian Peninsula, Basques, Catalans, Andalusians and Portuguese and two North African populations (Moroccan Arabs and Berbers). The aim of the study was to obtain accurate allele frequency data and other genetic parameters of forensic interest on the main representative human groups living in Iberia and Morocco using an automated method and commercial amplification kits.

Africa, Northern↗
PubMed2000

Genetic structure of north-west Africa revealed by STR analysis.

We have analysed a large set of autosomal short tandem repeat (STR) loci in several Arabic and Berber-speaking groups from north-west Africa (ie Moroccan Arabs, northern-central and southern Moroccan Berbers, Saharawis, and Mozabites). Two levels of analysis have been devised using two sets of 12STR loci, (D3S1358, vWA, FGA, THO1, TPOX, CSF1PO, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820) and 21 (the former set plus D9S926, D11S2010, D13S767, D14S306, D18S848, D2S1328, D4S243, F13A1, and FES/FPS). For each set, data for a number of external reference populations were gathered from the literature. Several methods of analysis based on genetic distances (neighbour-joining trees, principal coordinate analysis, boundary detection), as well as AMOVA, showed that genetic differentiation among NW African populations was very low and devoid of any spatial pattern. When the NW African populations were grouped according to cultural or linguistic differences, the partition was not associated with genetic differentiation. Thus, it is likely that Arabisation was mainly a cultural process. A clear genetic difference was found between NW African populations and Iberians, which underscores the Gilbraltar Straits as a strong barrier to genetic exchange; nonetheless, some degree of gene flow into Southern Iberia may have existed. NW Africans were genetically closer to Iberians and to other Europeans than to African Americans.

Africa, Northern↗
PubMed2000

Prevalence of 2314delG mutation in Spanish patients with Usher syndrome type II (USH2).

The Usher syndrome (USH) is a group of autosomal recessive diseases characterized by congenital sensorineural hearing loss and retinitis pigmentosa. Three clinically distinct forms of Usher syndrome have so far been recognized and can be distinguished from one another by assessing auditory and vestibular function. Usher syndrome type II (USH2) patients have congenital moderate-to-severe nonprogressive hearing loss, retinitis pigmentosa, and normal vestibular function. Genetic linkage studies have revealed genetic heterogeneity among the three types of USH, with the majority of USH2 families showing linkage to the USH2A locus in 1q41. The USH2A gene (MIM 276901) has been identified: three mutations, 2314delG, 2913delG, and 4353-54delC, were initially reported in USH2A patients, the most frequent of which is the 2314delG mutation. It has been reported that this mutation can give rise to typical and atypical USH2 phenotypes. USH2 cases represent 62% of all USH cases in the Spanish population, and 95% of these cases have provided evidence of linkage to the USH2A locus. In the present study, the three reported mutations were analyzed in 59 Spanish families with a diagnosis of USH type II. The 2314delG was the only mutation identified in our population: it was detected in 25% of families and 16% of USH2 chromosomes analyzed. This study attempts to estimate the prevalence of this common mutation in a homogeneous Spanish population.

Alleles↗
PubMed1999

Sex-specific migration patterns in Central Asian populations, revealed by analysis of Y-chromosome short tandem repeats and mtDNA.

Eight Y-linked short-tandem-repeat polymorphisms (DYS19, DYS388, DYS389I, DYS389II, DYS390, DYS391, DYS392, and DYS393) were analyzed in four populations of Central Asia, comprising two lowland samples-Uighurs and lowland Kirghiz-and two highland samples-namely, the Kazakhs (altitude 2,500 m above sea level) and highland Kirghiz (altitude 3,200 m above sea level). The results were compared with mtDNA sequence data on the same individuals, to study possible differences in male versus female genetic-variation patterns in these Central Asian populations. Analysis of molecular variance (AMOVA) showed a very high degree of genetic differentiation among the populations tested, in discordance with the results obtained with mtDNA sequences, which showed high homogeneity. Moreover, a dramatic reduction of the haplotype genetic diversity was observed in the villages at high altitude, especially in the highland Kirghiz, when compared with the villages at low altitude, which suggests a male founder effect in the settlement of high-altitude lands. Nonetheless, mtDNA genetic diversity in these highland populations is equivalent to that in the lowland populations. The present results suggest a very different migration pattern in males versus females, in an extended historical frame, with a higher migration rate for females.

Alleles↗
PubMed1999

Allele frequencies in a worldwide survey of a CA repeat in the first intron of the CFTR gene.

A dinucleotide CA repeat within intron 1 of the CFTR gene has recently been identified. We have determined the allele frequencies of this polymorphism in samples from 18 populations covering all major geographical areas, with a total of 1,816 chromosomes. When considering allele distributions, African populations presented a wider range of alleles than other populations and also presented higher expected heterozygosities. Analysis of molecular variance showed that 8.04% of the genetic variance in this locus could be attributed to differences among populations. We concluded that the polymorphism in the CA repeat in intron 1 of the CFTR gene is highly informative in populations from all geographical regions of the world. Thus, it can be applied to family studies of unknown mutations causing cystic fibrosis (CF) and can provide valuable information for genetic counseling. Moreover, its analysis should be included in the haplotypic analysis of known CF mutations.

Alleles↗
PubMed1998

HLA evidence for the lack of genetic heterogeneity in Basques.

To examine the possible internal heterogeneity within the Basque population, nine samples typed for several HLA loci were compiled and HLA-A, B, C and DR loci were analysed. First, the shared features of HLA in Basques were analysed by principal component analysis and genetic distances. Two major Basque dialect groups ('French' and 'Spanish') were considered. FST statistics were computed and corrected for sampling intensity. The dialectal and political division did not seem to differentiate these two groups genetically. Analysis of Molecular Variance also failed to show consistently significant genetic variance components between French and Spanish Basques. Thus, in this particular example, linguistic diversity does not seem to correlate with a genetic stratification.

Alleles↗
PubMed1998

Trading genes along the silk road: mtDNA sequences and the origin of central Asian populations.

Central Asia is a vast region at the crossroads of different habitats, cultures, and trade routes. Little is known about the genetics and the history of the population of this region. We present the analysis of mtDNA control-region sequences in samples of the Kazakh, the Uighurs, the lowland Kirghiz, and the highland Kirghiz, which we have used to address both the population history of the region and the possible selective pressures that high altitude has on mtDNA genes. Central Asian mtDNA sequences present features intermediate between European and eastern Asian sequences, in several parameters-such as the frequencies of certain nucleotides, the levels of nucleotide diversity, mean pairwise differences, and genetic distances. Several hypotheses could explain the intermediate position of central Asia between Europe and eastern Asia, but the most plausible would involve extensive levels of admixture between Europeans and eastern Asians in central Asia, possibly enhanced during the Silk Road trade and clearly after the eastern and western Eurasian human groups had diverged. Lowland and highland Kirghiz mtDNA sequences are very similar, and the analysis of molecular variance has revealed that the fraction of mitochondrial genetic variance due to altitude is not significantly different from zero. Thus, it seems unlikely that altitude has exerted a major selective pressure on mitochondrial genes in central Asian populations.

Africa↗
PubMed1998

HLA class I and class II DNA typing and the origin of Basques.

Seven HLA class I and class II loci (HLA-A, B, C, DRB1, DQA1, DPA1 and DPB1) were typed at the DNA level in two populations of the Iberian Peninsula (100 Basque and 88 Catalan individuals) in order to unravel their genetic relationship and to compare these results with other European and Mediterranean populations. For the first time, the frequencies of alleles and haplotypes for the class I HLA loci at the DNA level in these populations are presented. The most frequent haplotype in both populations is A*29-Cw*1601-B*44-DRB1*0701-DQA1*0201-DPA1*0103-DPB 1*0401. Neither population differed markedly from the highly homogeneous European and Mediterranean genetic landscape. The Basques, a European outlier population according to classical genetic markers, appear to lie within the genetic European variation with a slight uniqueness and show no clear relationship to North African populations, as has been postulated in some previous HLA studies. Here, the range of possibilities provided by the highly polymorphic HLA system is stressed by using genetic distances, phylogenetic trees and principal component analyses in order to reconstruct population history.

Alleles↗
PubMed1997

Population genetics of Y-chromosome short tandem repeats in humans.

Eight human short tandem repeat polymorphisms (STRs) also known as microsatellites-DYS19, DYS388, DYS390, DYS391, DYS392, DYS393, DYS389I, and DYS389II, mapping in the Y chromosome-were analyzed in two Iberian samples (Basques and Catalans). Allele frequency distributions showed significant differences only for DYS392. Fst and gene diversity index (D) were estimated for the Y STRs. The values obtained are comparable to those of autosomal STR if corrections for the smaller effective population size on the Y chromosome are taken into account. This suggests that Y-chromosome microsatellites might be as useful as their autosomal counterparts to both human population genetics and forensics. Our results also reinforce the hypothesis that selective sweeps in the Y chromosome in recent times are unlikely. Haplotypes combining five of the loci were constructed for 71 individuals, showing 29 different haplotypes. A haplotype tree was constructed, from which an estimate of 7,000 to 60,000 years for the age of the Y-chromosome variation in Iberia was derived, in accordance with previous estimates obtained with mtDNA sequences and nuclear markers.

Animals↗
PubMed1997

Microsatellite variation and the differentiation of modern humans.

This study presents an analysis of 20 tetranucleotide microsatellites in 16 worldwide human populations representing the major geographic groups. Global Fst values for the 20 microsatellites are indicators of their relative validity as tools in human population genetics. Four different measures of genetic distance (Fst, DSW, delta mu 2 and Rst) have been tested and compared with each other. Neighbor-joining trees have been constructed for all the measures of genetic distance and populations. Measures of genetic distance such as Fst, which does not consider different mutational relationships among alleles and has a known relationship to differentiation by drift, and to some extent DSW, reflect what is known of human evolution, while mutation-based distances such as Rst and delta mu 2 give very different results from those recognized from other sources (genetic or archaeological). When the genetic relationship between human populations is analyzed through allelic frequencies for microsatellites, the choice of distance may be a key issue in the picture obtained of genetic relationships between human populations. The results of the present study suggest that genetic drift played the main role in generating the present distributions of microsatellite alleles and their variation among human populations; the role of mutation must have been less important owing to the time constraint imposed by the small timescale in which most human differentiation has occurred. Moreover, the results support the theory of a recent origin of modern humans, although the existence of strong bottlenecks in the origin of the various human groups seems unlikely.

Analysis of Variance↗
PubMed1997

Mitochondrial DNA variation and the origin of the Europeans.

Sequences from the mitochondrial DNA (mtDNA) control region were analyzed in nine European and West Asian populations. They showed low genetic heterogeneity when compared to world populations. However, a Caucasoid population tree displayed a robust east-west gradient. Within-population diversity (ascertained through various parameters) and mean pairwise differences declined from east to west, in a pattern compatible with ancient population migration and expansion from the Middle East. Estimated expansion times indicate a Paleolithic event with important differences among populations according to their geographical position and thus a slower tempo than previously believed. The replacement of Neanderthals by anatomically modern humans, fully compatible with the present results, may have been a slower and more complex process than cultural change suggests.

DNA, Mitochondrial↗
PubMed1997

Genetics of retinoblastoma: a study.

We have analyzed 43 families with either familial retinoblastoma (RB) (four kindreds), bilateral sporadic RB (10 individuals), or unilateral sporadic RB (29 individuals). Genetic studies focused on karyotype analysis, loss of heterozygosity of intragenic polymorphisms, and search for point mutations. We have been able to identify the genetic defect underlying the disease in eight cases. Deletions have been found in three patients with sporadic RB, two bilateral in one of which karyotyping had previously detected an interstitial deletion of chromosome 13 affecting (q13-q31) and one unilateral. Five different point mutations were responsible for three cases of bilateral sporadic RB, one case of bilateral sporadic RB, and one case of bilateral familial RB. The low frequency of constitutional mutations found in our study has led us to review and evaluate the possibilities and limitations of the present genetic analyses on RB and to access the different factors influencing the detection of mutations causing the disease, because genetic counseling is mainly based on mutation identification.

Chromosomes, Human, Pair 13↗