647 research outputs found
Genome-based multidisciplinary approaches to the reconstruction of human demographic history
No full textIn my doctoral dissertation I summarize the scientific work leading to three papers in peer-reviewed journal, two submitted manuscripts. These entire studies share a common focus on human evolutionary history, but each of them address different scientific questions by means of a different combination of molecular and statistical methods.
Our cells contain a message from the past, written in their genomes; thus the study of genetic variation within and between populations can help us understand aspects of human demographic history over the past thousands of years, i.e. well beyond the time-limits of historical evidence.
Recently, extensive human genome data are becoming available, both from genome wide SNP data, and from the rapidly-increasing number of complete genome sequences, offering novel means of reconstructing human population history with a detail that was, until very few years ago, unthinkable. This abundant, and ever-growing amount of genomic data is of enormous relevant for understanding how and why human are different. Paper I (Barbujani et al., 2013) represents a review of human genetic variation and their implications for human evolutionary inference
Genetic data are indispensable to test hypothesis, generated in complementary discipline such as anthropology, linguistic and archaeology. Paper II (Tassi et al., submitted) and Paper III (Longobardi et al., submitted) provide examples of how it is possible to achieve a detailed picture of human history and evolution, taking advantage of archaeological and linguistic knowledge to interpret the genetic data.
For many years, studies of human genetic diversity have been necessarily limited to modern populations, severely limiting our ability to investigate the detail of past processes. Conversely, today, thanks to the advent of methods for reliably typing ancient DNA, it has been possible to increase our power to reconstruct historical demographic processes, and to explicitly test evolutionary hypotheses. In Paper IV (Ghirotto et al., 2013) and Paper V (Tassi et al., 2013) we analyzed ancient Etruscans sample and, within the ABC framework, we explicitly compared several models, differing for demographic and genealogical histories, to shed light on the origin and evolution of the Etruscans
Effect of 5-fluorouracil on growth and mophogenesis of tissue cultures of Nicotiana sylvestris
No full textGenetic data in forensic science: Use, misuse and abuse
No full textThe diffusion of databases storing genetic information and health records for many citizens is clearly beneficial both for health care and for research, but is raising problems related with the possibility of misuse and abuse of these data. In this paper, we discuss the potential and limitations of DNA-based methods of forensic interest, starting from genetic profiling. We then move on to three related areas, and show that research so far has helped us understand the genetic bases of the probability to develop diseases, but has not identified genes that might (a) predispose to aggressive behavior, (b) allow racial categorization, and (c) make the person who carries them unsuitable for certain jobs or for raising step children. However, science is often misunderstood as producing certainties, and so sensitive biological information must be protected to avoid potentially serious violations of individual rights
Glutamate dehydrogenase specific activity and its isoenzymatic pattern are carbon source dependent in callus cultures of Nicotiana plumbaginifolia.
No full textNine things to remember about human genome diversity
No full textUnderstanding how and why humans are biologically different is indispensable to get oriented in the ever-growing body of genomic data. Here we discuss the evidence based on which we can confidently state that humans are the least genetically variable primate, both when individuals and when populations are compared, and that each individual genome can be regarded as a mosaic of fragments of different origins. Each population is somewhat different from any other population, and there are geographical patterns in that variation. These patterns clearly indicate an African origin for our species, and keep a record of the main demographic changes accompanying the peopling of the whole planet. However, only a minimal fraction of alleles, and a small fraction of combinations of alleles along the chromosome, is restricted to a single geographical region (and even less so to a single population), and diversity between members of the same population is very large. The small genomic differences between populations and the extensive allele sharing across continents explain why historical attempts to identify, once and for good, major biological groups in humans have always failed. Nevertheless, racial categorization is all but gone, especially in clinical studies. We argue that racial labels may not only obscure important differences between patients but also that they have become positively useless now that cheap and reliable methods for genotyping are making it possible to pursue the development of truly personalized medicine. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Caratterizzazione dei prodotti della trascrizione e della traduzione in colture di calli di gerbera sottoposte a deprivazione di fonti di carbonio.
No full textRisposta allo stress da deprivazione di fonti di carbonio: modificazioni del metabolismo cellulare e della sintesi proteica in colture di calli di Gerbera jamesonii var. hybrida.
No full textGenetic evidence does not support an etruscan origin in Anatolia
No full textThe debate on the origins of Etruscans, documented in central Italy between the 8th and the 1st century BC, dates back to the antiquity. Herodotus described them as a group of immigrants from Lydia, in Western Anatolia, whereas for Dionysus of Halicarnassus they were an indigenous population, a view shared by most modern archaeologists. Claims about an Anatolian origin of the Etruscans, based on similarities between the mtDNAs of contemporary Turks and Tuscans, were not confirmed by the analysis of ancient DNA data. In this study we tested alternative models of Etruscan origins by Approximate Bayesian Computation methods, comparing levels of genetic diversity in the mtDNAs of modern and ancient populations, with those obtained by millions of computer simulations. The results show that that the observed genetic similarities between modern Tuscans and Anatolians cannot be attributed to an immigration wave from the East leading to the onset of the Etruscan culture in Italy. Genetic links between Tuscany and Anatolia do exist, but date back to a remote stage of prehistory, possibly but not necessarily to the spread of farmers during the Neolithic period
No evidence of Neandertal admixture in the mitochondrial genomes of early European modern humans and contemporary Europeans
No full textNeandertals, the archaic human form documented in Eurasia until 29,000 years ago, share no mitochondrial haplotype with modern Europeans. Whether this means that the two groups were reproductively isolated is controversial, and indeed nuclear data
have been interpreted as suggesting that they admixed.
We explored the range of demographic parameters that
may have generated the observed mitochondrial diversity,
simulating 3.0 million genealogies under six models differing as for the relationships among contemporary Europeans, Neandertals, and Upper Palaeolithic European early modern humans (EEMH), who coexisted with Neandertals for millennia. We compared by Approximate Bayesian Computations the simulation results with mitochondrial diversity in 7 Neandertals, 3 EEMH, and 150 opportunely chosen modern Europeans. A model of genealogical continuity between EEMH and contemporary
Europeans, with no Neandertal contribution, received
overwhelming support from the analyses. The maximum
degree of Neandertal admixture, under the model of gene
flow supported by nuclear data, was estimated at 1.5%, but
this model proved 20–32 times less likely than a model
without any gene flow. Nuclear and mitochondrial evidence
might be reconciled if smaller population sizes led to
faster lineage sorting for mitochondrial DNA, and Neandertals
shared a longer period of common ancestry with
the non-African’s than with the African’s ancestors
Supplemental material for Small vessel disease and biomarkers of endothelial dysfunction after ischaemic stroke
No full textSupplemental material for Small vessel disease and biomarkers of endothelial dysfunction after ischaemic stroke by Francesco Arba, Alessio Giannini, Benedetta Piccardi, Silvia Biagini, Vanessa Palumbo, Betti Giusti, Patrizia Nencini, Anna Maria Gori, Mascia Nesi, Giovanni Pracucci, Giorgio Bono, Paolo Bovi, Enrico Fainardi, Domenico Consoli, Antonia Nucera, Francesca Massaro, Giovanni Orlandi, Francesco Perini, Rossana Tassi, Maria Sessa, Danilo Toni, Rosanna Abbate and Domenico Inzitari in European Stroke Journal</p
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