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S Dios

Publications and source records attributed to S Dios.

10 recordsLinked to original sources
PubMed2006

Suppression subtraction hybridization (SSH) and macroarray techniques reveal differential gene expression profiles in brain of sea bream infected with nodavirus.

Despite of the impact that viruses have on aquatic organisms, relatively little is known on how fish fight against these infections. In this work, the brain gene expression pattern of sea bream (Sparus aurata) in response to nodavirus infection was investigated. We used the suppression subtractive hybridization (SSH) method to generate a subtracted cDNA library enriched with gene transcripts differentially expressed after 1 day post-infection. Some of the ESTs from the infected tissues fell in gene categories related to stress and immune responses. For the reverse library (ESTs expressed in controls compared with infected tissues) the most abundant transcripts were of ribosomal and mitochondrial nature. Several ESTs potentially induced by virus exposure were selected for in vivo expression studies. We observed a clear difference in expression between infected and control samples for two candidate genes, ubiquitin conjugating enzyme 7 interacting protein, which seems to play an important role in apoptosis and the interferon induced protein with helicase C domain 1 (mda-5) that contributes to apoptosis and regulates the type I IFN production, a key molecule of the antiviral innate response in most organisms.

Amino Acid Sequence↗
PubMed2004

Admixture in the Hispanics of the San Luis Valley, Colorado, and its implications for complex trait gene mapping.

Hispanic populations are a valuable resource that can and should facilitate the identification of complex trait genes by means of admixture mapping (AM). In this paper we focus on a particular Hispanic population living in the San Luis Valley (SLV) in Southern Colorado. We used a set of 22 Ancestry Informative Markers (AIMs) to describe the admixture process and dynamics in this population. AIMs are defined as genetic markers that exhibit allele frequency differences between parental populations >or=30%, and are more informative for studying admixed populations than random markers. The ancestral proportions of the SLV Hispanic population are estimated as 62.7 +/- 2.1% European, 34.1 +/- 1.9% Native American and 3.2 +/- 1.5% West African. We also estimated the ancestral proportions of individuals using these AIMs. Population structure was demonstrated by the excess association of unlinked markers, the correlation between estimates of admixture based on unlinked marker sets, and by a highly significant correlation between individual Native American ancestry and skin pigmentation (R2= 0.082, p < 0.001). We discuss the implications of these findings in disease gene mapping efforts.

Adult↗
PubMed2003

Molecular phenotyping of a trinucleotide repeat (D5S373) experimental conditions.

The aim of this study is to assess the utility of the STR D5S373 in human identification. PCR amplification and electrophoretic separation were optimized in order to achieve unambiguous phenotyping. We concluded that primer concentration and annealing temperature are the main factors affecting the specificity of PCR. In our population survey including three human major groups (Europe, Sub-Saharan Africa, and Asia), up to six alleles and six interalleles have been found ranging in size from 86 to 101 bp. The phenotypes were determined using horizontal polyacrylamide gel electrophoresis, a technique which has turned out to be suitable for separating fragments as close as 1 bp. In each population, the genotype frequencies conformed to the expectations of genetic equilibrium. Sequence studies were carried out to make the allele nomenclature fit to ISFH recommendations. Results from our population analysis of D5S373 show clear differences in allelic frequency patterns among the three major human groups examined. Human identification parameters estimated from our study are similar to those obtained for other STRs currently used in DNA testing.

Alleles↗
PubMed2003

DYS19 and DYS390 Y-STR polymorphism in the Iberian Peninsula: a multivariate analysis.

Genetic polymorphism of two Y-specific short tandem repeats (DYS19 and DYS390) was investigated in six populations from the Iberian Peninsula (Andalusia, Castilla-La Mancha, Castilla-Leon, Extremadura, Galicia and South East Spain) comprising a total of 895 unrelated and native individuals, and a complete database of DYS19 and DYS390 allele frequency distributions in 34 world-wide populations collected from literature was analysed. DYS19 and DYS390 polymorphism was screened by automated fluorescence analysis of PCR-amplified labelled sample fragments performed with and ABI PRISM 377 Genetic Analyser. The degree of population differentiation was analysed using the STP Test to calculate G Statistic values. Correspondence Analysis based on the allelic frequencies of each locus and combining both was performed using the NTSYS-PC version 1.70 computer package. The diversity of the genetic profiles of gene frequencies suggests an important population heterogeneity in the Iberian Peninsula as a whole (DYS390 being particularly evident), which is corroborated after statistical analyses (G = 139.8457, p = 1.7822 x 10(-14) for DYS19, G = 116.0293, p = 4.6845 x 10(-12) for DYS390). However, multivariate analysis indicates a well defined cluster of the populations of the Central region, and sets them apart from the positions within which peripheral Iberian Peninsula populations are distributed. The Galician population shows trends which bring it closer to the positions throughout which European Atlantic populations are distributed. The results shown by the Central Iberian Peninsula seem to lend support to a model of settlement population stocks which came from the region of Castilla-Leon after the Islam invasions, whereas in the South-East populations the genetic record of Middle Eastern populations is still present, a consequence of the expansion of Islam in Southern Europe in the Middle Ages.

Alleles↗
PubMed2001

Sub-Saharan genetic contribution in Morocco: microsatellite DNA analysis.

Northwest African populations occupy a strategic geographical area that has always been a zone of influence for diverse human groups from different regions. This article focuses on the analysis of the genetic contribution of sub-Saharan African populations by means of four short tandem repeat (STR) systems (HUMTPOX, HUMVWA31/A, HUMTHO1, and HUMF13B), which have proven informative in establishing genetic relationships between human populations. Genetic trees and multivariate analyses of European and Near Eastern populations show that the Moroccan population shares a common genetic substrate with all of them. However, the latter defines a specific lineage. Evolutionary factors inherent in the population's geographical isolation in early times, together with genetic flow from sub-Saharan populations (mainly as reflected by HUMF13B and HUMTPOX), appear to be particularly relevant in understanding the peculiarities of the genetic character of the present-day population.

Africa South of the Sahara↗
PubMed2001

Melting curve analysis of SNPs (McSNP): a gel-free and inexpensive approach for SNP genotyping.

High-throughput methods for assaying DNA variation require two important steps: (i) discriminating the variation and (ii) detecting the signal. In this report, we describe a novel SNP genotyping method that we refer to as melting curve analysis of SNPs (McSNP). McSNP combines a classic approach for discriminating alleles, restriction enzyme digestion, with a more recent method for detecting DNA fragments, melting curve analysis. Melting curve analysis is performed by slowly heating DNA fragments in the presence of the dsDNA-specific fluorescent dye SYBR Green I. As the sample is heated, fluorescence rapidly decreases when the melting temperature of a particular fragment is reached. We show that it is possible to determine the composition of simple mixtures of DNA fragments, such as those that result from restriction enzyme digestions of short PCR products. McSNP is well suited for high-throughput genotyping because 96 samples can be analyzed and automatically scored in 20 min. Our results clearly demonstrate that McSNP is a simple, inexpensive, and accurate means of genotyping SNP variation.

Genotype↗
PubMed1998

Population database of STRs in west Africa: a genetic study of TPOX, HUMVWA31/A, HUMTH01, and CYP19.

Four tetrameric STRs (TPOX, HUMVWA31/A, HUMTH01, and CYP19) were analysed in a West African population (Cabo Verde). No significant deviations from Hardy-Weinberg proportions were observed, either in conventional or exact tests. Pairwise comparisons confirmed allelic independence for all the combinations of loci. Data is provided for the first time about CYP19 in Black populations. In comparisons between African and Afro-American populations, significant frequency differences for several alleles at the TH01 and VWA31/A loci were observed. The allele frequencies provided in this study contribute to a better knowledge of the variability of these markers among the main human groups, especially in the context of Subsaharan African populations.

Africa, Western↗
PubMedDate not supplied

New STR at the D5S373 locus and its relevance in human population studies.

The genetic analysis of a new trinucleotide repeat (D5S373) was carried out with a view to its application in both individual genetic profiling and human population genetics. In a screening analysis from seven world populations (n = 706) and after nucleotide sequence analysis, up to nine alleles were found corresponding to 8-13 repetitions of a TAA motif. This analysis shows He values ranging between 0.689-0.762. D5S373 reveals interpopulational variability which leads to specific frequency profiles in the major human groups, with alleles 8, 11, l2, and 13 being particularly informative, which suggests the that this marker may be of interest in the biological study of human populations.

Africa, Western↗