The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. http://http://dspace.unitus.it:80 2013-05-25T15:27:21Z 2013-05-25T15:27:21Z Mariotti, Marco http://hdl.handle.net/2067/679 2011-01-25T10:16:04Z 2008-04-20T22:00:00Z

Title: Polimorfismi nei geni Toll-like receptor 2, 4 e 6 in Bos taurus Authors: Mariotti, Marco Abstract: I Toll-like receptor (TLR) rivestono un ruolo fondamentale contro i patogeni. L’elemento chiave per l’iniziazione della risposta immunitaria innata è l’identificazione di uno o più componenti di batteri o virus che non sono normalmente presenti nell’ospite. Queste componenti sono state definite Pathogen-Associated Molecular Patterns (PAMP) I TLR sono abbondanti sulla superficie di macrofagi e neutrofili, oltre che sulle cellule epiteliali che rivestono polmoni e intestino. Essi agiscono da sistema di allarme per avvisare sia il sistema immunitario innato che quello adattativo, che si sta formando un’infezione. Molecole correlate a Toll (proteina transmembrana della Drosphila) ai TLR sono chiaramente coinvolte nell’immunità innata in tutti gli organismi multicellulari. In questo studio sono stati analizzati i geni TLR2, TLR4 e TLR6 in Bos Taurus, con i seguenti scopi: - Individuare eventuali SNPs che siano in qualche modo correlati con alcune malattie nel bovino: mastite, IBR (Infectious Bovine Rhinotracheitis), para-tubercolosi e enterite. In modo da sottolineare una possibile predisposizione genetica. - Caratterizzare gli SNPs individuati analizzandone frequenza e diversità genetica in popolazioni appartenenti a 16 razze bovine europee. - Verificare se alcune razze presentano peculiari polimorfismi nei TLR e se questo possa essere associato alle caratteristiche della razza. Sono stati identificati 8 nuovi SNPs in geni di grande importanza nella risposta ai patogeni. Di questi uno risulta essere uno SNP non sinonimo, e conseguentemente meriterebbe di essere studiato in dettaglio. Gli SNPs sono stati caratterizzati su 951 individui appartenenti a 16 delle principali razze bovine europee. Le informazioni, unite al fatto che gli 8 SNPs sono risultati marcatori neutrali in base all’analisi con FDIST, ne possono permettere l’utilizzo in studi di genetica di popolazione nei bovini. Per quanto riguarda l’associazione dei polimorfismi ad alcune malattie bovine, i dati sono ancora preliminari. Tuttavia, in particolare per quanto riguarda l’IBR, le analisi saranno condotte su un maggior numero di individui per confermare l’assenza nei sani dell’eterozigote A/G nel locus TLR4_254, l’assenza della base C nel locus 4_1678 e l’assenza della base T nel locus TLR4_2043.; In mammals, Toll-like receptors (TLRs) play a primary role in the recognition of pathogen-associated molecular patterns. Innate immune response starts when some bacterial or viral components are identified. Such components are defined Pathogen-Associated Molecular Patterns (PAMP) TLRs are abundant on the surface of macrofages and neutrophils and on the epithelial cells of lung and bowel. Their role is alerting the immune system when an infection is developing. Molecules related to TLRs are involved in the innate immunity of all multiicellular organisms. In this work Bos Taurus genes TLR2, TLR4 e TLR6 were considered, aiming at: - Identifying SNPs that could be associated with cattle diseases such mastitis, IBR (Infectious Bovine Rhinotracheitis), paratuberculosis and enteritis, to verify if a genetic susceptibility to developing diseases can be observed. - Characterizing the discovered SNPs by analysing their frequency and diversity in populations of 16 European breeds. - Verifying if some breeds show peculiar TLRs polymorphisms and if they can be breed characteristics. We identified 8 SNPs in genes of great relevance in the response to pathogens. One of the SNPs is not synonymous, and it should be fully studied in the future. The SNPs were characterized on 951 individuals belonging to 16 of the main European cattle breeds. The described SNPs, that resulted neutral markers after a FDist analysis, can be used in studies of population genetics in cattle. As for the association between polymorphisms and diseases, data are still preliminary, However, particularly for IBR, the analyses will be performed on a wider number of samples to confirm the absence of heterozygote A/G in locus TLR4_254, of base C in locus TLR4_1678 and of base T in locus TLR4_2043 in control animals. Description: Tesi di laurea. Facoltà di Scienze MM.FF.NN. Corso di laurea in Scienze biologiche. Indirizzo biomolecolare. A.a. 2006/2007. Relatore Giorgio Prantera. Correlatore Lorraine Pariset. Controrelatore Pasquale Mosesso.

2008-04-20T22:00:00Z Pariset, Lorraine Mariotti, Marco Nardone, Alessandro Soysal, M. Ihsan Ozkan, Emel Williams, J. L. Dunner, Susana Leveziel, Hubert Maróti-Agóts, Ákos Bodò, I. Valentini, Alessio http://hdl.handle.net/2067/1890 2011-05-30T05:42:46Z 2011-04-06T22:00:00Z

Title: Relationships of Podolic cattle breeds assessed by single nucleotide polymorphisms (SNPs) genotyping Authors: Pariset, Lorraine; Mariotti, Marco; Nardone, Alessandro; Soysal, M. Ihsan; Ozkan, Emel; Williams, J. L.; Dunner, Susana; Leveziel, Hubert; Maróti-Agóts, Ákos; Bodò, I.; Valentini, Alessio Abstract: Italian Maremmana, Turkish Grey and Hungarian Grey breeds belong to the same Podolic group of cattle, have a similar conformation and recently experienced a similar demographic reduction. The aim of this study was to assess the relationship among the analysed Podolic breeds and to verify whether their genetic state reflects their history. To do so, approximately 100 single nucleotide polymorphisms (SNPs) were genotyped on individuals belonging to these breeds and compared to genotypes of individuals of two Italian beef breeds, Marchigiana and Piemontese, which underwent different selection and migration histories. Population genetic parameters such as allelic frequencies and heterozygosity values were assessed, genetic distances calculated and assignment test performed to evaluate the possibility of recent admixture between the populations. The data show that the physical similarity among the Podolic breeds examined, and particularly between Hungarian Grey and Maremmana cattle that experienced admixture in the recent past, is mainly morphological. The assignment of individuals from genotype data was achieved using Bayesian inference, confirming that the set of chosen SNPs is able to distinguish among the breeds and that the breeds are genetically distinct. Individuals of Turkish Grey breed were clearly assigned to their breed of origin for all clustering alternatives, showing that this breed can be differentiated from the others on the basis of the allelic frequencies. Remarkably, in the Turkish Grey there were differences observed between the population of Enez district, where in situ conservation studies are practised, and that of Bandirma district of Balikesir, where ex situ conservation studies are practised out of the original raising area. In conclusion, this study demonstrates that molecular data could be used to reveal an unbiased view of past events and provide the basis for a rational exploitation of livestock, suggesting appropriate cross-breeding plans based on genetic distance or breeding strategies that include the population structure.

2011-04-06T22:00:00Z Mariotti, Marco Williams, John L. Dunner, Susana Valentini, Alessio Pariset, Lorraine http://hdl.handle.net/2067/1885 2011-04-08T00:30:34Z 2011-04-05T22:00:00Z

Title: Polymorphisms within the Toll-Like Receptor (TLR)-2, -4, and -6 Genes in Cattle Authors: Mariotti, Marco; Williams, John L.; Dunner, Susana; Valentini, Alessio; Pariset, Lorraine Abstract: In mammals, members of the TLR gene family play a primary role in the recognition of pathogen-associated molecular patterns from bacteria, viruses, protozoa and fungi. Recently, cattle TLR genes have been mapped to chromosomes using a radiation hybrid panel. Nucleotide sequences of bovine TLR2, TLR4 and TLR6 genes were screened to identify novel SNPs that can be used in studies of cattle resistance to diseases. In total, 8 SNPs were identified and were submitted to the NCBI dbSNP database. The frequencies of the SNPs were assessed in 16 different bovine European cattle breeds and a phylogenetic analysis carried out to describe the relationships between the breeds. Even if from our analysis the SNPs do not appear located in loci under selection, a deviation of three SNPs from Hardy Weinberg equilibrium was observed, and we hypothesize that some of the polymorphisms may be fixated since many generations. The described variations in immune function related genes will contribute to research on disease response in cattle. In fact, the SNPs can be used in association studies between polymorphisms and cattle resistance to diseases.

2011-04-05T22:00:00Z