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Genetic Make (genetic + make)

Distribution by Scientific Domains

Life Sciences	60%
Medical Sciences	40%

Selected Abstracts

Genetic make up and structure of Colombian populations by means of uniparental and biparental DNA markers

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2010
Winston Rojas
Abstract Colombia is a country with great geographic heterogeneity and marked regional differences in pre-Columbian native population density and in the extent of past African and European immigration. As a result, Colombia has one of the most diverse populations in Latin America. Here we evaluated ancestry in over 1,700 individuals from 24 Colombian populations using biparental (autosomal and X-Chromosome), maternal (mtDNA), and paternal (Y-chromosome) markers. Autosomal ancestry varies markedly both within and between regions, confirming the great genetic diversity of the Colombian population. The X-chromosome, mtDNA, and Y-chromosome data indicate that there is a pattern across regions indicative of admixture involving predominantly Native American women and European and African men. Am J Phys Anthropol 143:13,20, 2010. © 2010 Wiley-Liss, Inc. [source]

Secreted factors from ventral telencephalon induce the differentiation of GABAergic neurons in cortical cultures

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2006
H.-h. Trinh
Abstract It is widely believed that the pyramidal cells and interneurons of the cerebral cortex are distinct in their origin, lineage and genetic make up. In view of these findings, the current thesis is that the phenotype determination of cortical neurons is primarily directed by genetic mechanisms. Using in vitro assays, the present study demonstrates that secreted factors from ganglionic eminence (GE) of the ventral telencephalon have the potency to induce the differentiation of a subset of cortical neurons towards ,-aminobutyric acid (GABA)ergic lineage. Characterization of cortical cultures that were exposed to medium derived from GE illustrated a significant increase in the number of GABA-, calretinin- and calbindin-positive neurons. Calcium imaging together with pharmacological studies showed that the application of exogenous medium significantly elevated the intracellular calcium transients in cortical neurons through the activation of ionotropic glutamate receptors. The increase in GABA+ neurons appeared to be associated with the elevated calcium activity; treatment with blockers specific for glutamate receptors abolished both the synchronized transients and reduced the differentiation of GABAergic neurons. Such studies demonstrate that although intrinsic mechanisms determine the fate of cortical interneurons, extrinsic factors have the potency to influence their neurochemical differentiation and contribute towards their molecular diversity. [source]

Tuscany autochthonous cattle breeds: an original genetic resource investigated by AFLP markers

JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 1 2006
R. Negrini
Summary The aim of this study was to assess the genetic diversity of four autochthonous cattle breeds of Tuscany and their relationships in comparison with Italian Friesian and Italian Brown, using amplified fragment length polymorphism markers. A total of 212 individuals were genotyped with three primer combinations generating 102 polymorphic markers. Average expected heterozygosity ranged from 0.23 in Mucca Pisana to 0.26 in Chianina, Italian Friesian, Italian Brown and Maremmana. The differences resulted not significant (Kruskall,Wallis test, p = 0.416). Gst-B index revealed that 86% of the total genetic variance is retained within population and only 14% is accounted by the between populations component. Multivariate analysis at individual and population level indicated that: (i) Calvana and Chianina are quite separate from the other breeds as an effect of the bottleneck experienced or as a signature of different origin; (ii) Podolian, Maremmana and Italian Brown clustered with the double purpose Mucca Pisana, revealing their contribution to its admixed genetic make up; (iii) Italian Friesian behaved always as out group. The ,analysis of molecular variance' recovered a significant subdivision clustering the six populations into three groups: Italian Friesian and Italian Brown versus Maremmana and Mucca Pisana versus Chianina and Calvana (6% of the total variance). [source]

RNA interference in protozoan parasites

CELLULAR MICROBIOLOGY, Issue 6 2004
Elisabetta Ullu
Summary RNA interference or RNAi is defined as the mechanism through which gene-specific, double-stranded RNA (dsRNA) triggers degradation of homologous transcripts. Besides providing an invaluable tool to downregulate gene expression in a variety of organisms, it is now evident that RNAi extends its tentacles into both the nucleus and the cytoplasm and is involved in a variety of gene silencing phenomena. Here we review the current status of RNAi in protozoan parasites that cause diseases of considerable medical and veterinary importance throughout Africa, Asia and the Americas. RNAi was first discovered in Trypanosoma brucei, a species of the family Trypanosomatidae, and it rapidly became the method of choice to downregulate gene expression in these organisms. At the same time, mechanistic studies exposed a role for RNAi in the control of retroposon transcript abundance. Whereas RNAi is also present in T. congolense, other members of the same family of organisms, namely T. cruzi and Leishmania major, are RNAi-negative. In apicomplexan parasites, there is experimental evidence for RNAi in Plasmodium, but this is not supported by their genetic make up. In contrast, the genome of Toxoplasma gondii harbours gene candidates with convincing similarity to ,classical' RNAi genes. Thus, as previously shown in fungi, protozoan parasites are genetically heterogeneous as far as the RNAi pathway is concerned. Finally, database mining predicts that Entamoeba histolytica and Giardia intestinalis have an RNAi pathway and the presence of RNAi genes in Giardia supports the view that gene silencing by dsRNA appeared very early during evolution of the eukaryotic lineage. [source]

Cytokine gene polymorphisms and sudden infant death syndrome

ACTA PAEDIATRICA, Issue 3 2010
L Ferrante
Abstract Aim:, Several studies indicate that the mucosal immune system is stimulated in cases of sudden infant death syndrome (SIDS), and our hypothesis is that this immune reaction is because of an unfavourable combination of functional polymorphisms in the cytokine genes. Methods:, Thus, in this study, single nucleotide polymorphisms (SNPs) in the genes encoding IL-6, IL-8, IL-12, IL-13, IL-16, IL-18 and IFN, were investigated in 148 SIDS cases, 56 borderline SIDS cases, 41 cases of infectious death and 131 controls. Results:, Regarding genotype distribution, no differences between the investigated groups were found. However, in the SIDS group, the genotypes IL-8 ,251AA/AT and IL-8 ,781CT/TT were significantly more frequent in the SIDS cases found dead in a prone sleeping position, compared with SIDS cases found dead in other sleeping positions. In addition, there was an association between fever prior to death and the genotype IL-13 +4464GG in the cases of infectious death. Conclusion:, This study indicates that specific interleukin genotypes are a part of a genetic make up that make infants sleeping prone at risk for SIDS. [source]