Conservazione e valorizzazione delle risorse genetiche animali autoctone

The conservation and enhancement of indigenous animal genetic resources is a field of theoretical study and application that are taking increasing interest and importance, especially in this new millennium in which global changes continue to accelerate and the need for sustainable and often localized agriculture, is becoming more prevalent (FAO, The State of Food and Agriculture, 2012, http://www.fao.org/catalog/inter-e.htm). The study of this thesis also financed by Veneto Region with a scholarship, is focused, through the presentation of four contributions, to the study of indigenous sheep genetic resources in Veneto region, with particular reference to the center of conservation at the Experimental Farm for the Mountain "Villiago" (Veneto Agriculture - Regional Agency for Agricultural sectors, Forestry and Food) Sedico (BL) (Annex I). The first contribution is about the characterization of Veneto sheep breeds with limited diffusion recognized in R.A. (Alpagota, Brogna, Foza and Lamon), through a genetic investigation with the use of a panel of 17 microsatellite markers (FASS, 1999; ISAG / FAO, 2004) and in relation to an Italian breed recognized in L.G. (Appenninica) used as an outgroup. To try to evaluate the influence of the structures of subpopulation (if present), total data were considered in the experimental plan in two ways: - as a single sample population ; - as two sample populations, divided into a main institutional farm called "main flock" ("Villiago"), which contains all 4 breeds of Veneto region, and into secondary farms called "secondary flocks" (essentially private breeders). In general, it was found that Veneto sheep breeds show a considerable genetic variability, in terms of number of alleles and heterozygosity with respect to the breed of reference, which proved to be the least variable (0.663). However, a significant deficit of heterozygotes was observed in every breed due to rather high levels of consanguinity or for the presence of substructures in the population, probably due to greater genetic variation in populations founders with respect to the latter. Considering the sample population divided into "main flock" and "secondary flocks," there has been a genetic differentiation between primary and secondary flocks within each breed, in terms of total number of alleles, allelic richness and reduction in genetic diversity. In general from total samples, not considering the division into "main flock" and "secondary flocks", the contribution of genetic diversity is between -0.954%, removing from the data set the Appenninica, to +1.357%, removing Alpagota. Considering the division between "main flock" and "secondary flocks", the results obtained from the main group are different from secondary groups: removing the subjects of "secondary flocks" the maximum value has been reached by removing the breeds Alpagota (-7.415) and Brogna (-6.390), while not considering breeds Foza and Lamon in both primary and secondary groups, the value obtained is always negative (Foza: -0.209, -6.237, Lamon: 0.949, -2.795, for "main flock" and "secondary flocks", respectively). In summary, the results of this study show the importance to compare the genetic diversity among primary and secondary flocks to safeguard native sheep breeds , especially in the guidelines that the institutions should provide in conservation programs to protect institutional and private farms, by providing separate and targeted actions. The results obtained are served, also, for the realization of a technical-informative layman for breeders (Annex II). The second contribution is to study the generational simulations through the use of Hybridlab software, in order to evaluate a first hypothesis about the possible effects of a selection of genotypes not susceptible to the development of neurodegenerative disease scrapie in native sheep breeds; the study concerns in particular the approach to generational simulations in groups of sheep that do not have the pedigree data. In this case the genetic variability of two groups of subjects from two native sheep breeds of Veneto region, Alpagota and Brogna (118 subjects in total, of which 23 ♂ and 42 ♀ for Brogna, 27 ♂ and 26 ♀ for Alpagota), was studied by genetic analysis with the application of 17 microsatellite markers, as in the protocol followed in the study of the first contribution of this work. The molecular data obtained were used for the simulation of subsequent generations of the two breeds, according to a scheme of intersections within the breed and on the basis of the choice of breeding males in relation to the genotypic data of scrapie susceptibility. The assumptions behind the work required for the coupling plane, were: - the allele frequencies of the sample of animals are representative of the original populations; - all rams and all females have the same reproductive performances; - males are selected by a random drawing and are used only for one round of mating; - the number of animals who makes up the sample population is fixed. For each breed were carried out four new simulated successive generations, expanding the population at time zero up to 1000 individuals and selecting more than 500 subjects representative of the real population (for allele frequencies and sex). On these simulated populations at time zero, considered representative of the real situation of departure, we proceeded to apply a selection scheme with internal selection of 10% of the internal real consistency, sex ratio of offspring about 50%, average fertility 145%, use of males for only one round of mating and never in reproductive round (season) after birth, but in the next. The selection, on the basis male, was performed using two different approaches: discarding males with scrapie unfavorable genotype (Hazard Class V genotypes VRQ / VRQ, ARQ / VRQ and ARH / VRQ) and without selection of the genotype. The subjects deleted were chosen randomly among those eligible for selection. It was found that the total number of alleles detected in Alpagota was of 158 (average 9:29 ± SD 2.95), and in Brogna was 186 (mean 10.94 ± SD 3.05). The differences in the mean number of alleles, expected and observed heterozygosity, and molecular coancestry are determined by the selected and non-selected populations of both breeds. The results showed that if the assumptions are met and the generational analysis is corrected by the use of Hybridlab software, selection against susceptibility to scrapie is possible in studied local breeds with reduced diffusion , without compromising the genetic diversity. The third contribution was made consecutive to the first two, and as a continuation of the same. It is based on molecular data of those animals tested in the first contribution and aims to try to answer two questions that a researcher might ask as a result of the theoretical analysis of generational simulation of populations: - "What would happen if there was in fact the direct and immediate removal of individuals as the result of a selection plan of subjects to high susceptibility to develop scrapie, and then in real populations?" - "Is possible to imagine a description of the current population at time zero?" To do this, we used data from real animals characterized in the first contribution of this thesis, extrapolating 394 individuals belonging to four Veneto sheep breeds, with the following specifications: 110 Alpagota, 186 Brogna, 55 and 43 Foza Lamon. In addition to the molecular characterization of 17 microsatellite markers, we have used the information from genotyping for verification of haplotype associated with the PrP gene, believed to be associated with the degree of susceptibility to developing the disease. So, I created 31 different punctual datasets, in relation to the removal of all combinations of haplotypes classified in the table of risk class indicated by the European Commission. The relative abundance of populations is different: - whole population (394 subjects); - population with removal of the male and female of risk class V (332 subjects); - population with subjects of risk class IV and V together (ie with complete removal of the VRQ allele from the population, for a total of 134 subjects). The statistical analysis of the datasets considered useful showed that the total number of alleles detected is equal to 286, with a minimum value of 11 for the loci McM527 and MAF65 and maximum value of 23 for the loci CSRD247 and INRA063. The allelic frequency relative to the alleles detected ARR, AHQ, ARK, ARQ, ARH and VRQ varies between breeds, but in all the ARQ allele is more prevalent. While the observed heterozygosity, passing from the analysis of data relating whole population to those of the other two populations without risk class V and risk class V and IV of individuals, would increase only in all cases for Brogna, for Lamon increases only between the last two categories, while for all breeds the average number of alleles drastically decreases. Finally, only the population of subjects of breed Lamon has reduced the loss in genetic diversity by comparing the three categories of dataset. In general, then, we can say that if we consider the selection of subjects in Veneto sheep breeds, in relation to the sampled data and assuming that these are representative of the real situation of entirely breeding populations, there is a possible general loss of biodiversity raised. In the fourth contribution, however, the conservation and development of animal genetic resources was investigated by an indirect approach, assuming that if there are glaring differences between individuals of different breeds and between breeds, there may also be differences expressed at the microscopic level. In this specific case it was decided to use a method of comparison of the wool, emphasizing the micro-morphometric structural features of hair surface, focusing on forms of cuticle. To try to reduce the error of the operator that should be adequately trained to recognize and classify the changing cuticular shapes, it has developed a method based on the measurement by microscopy image and subsequent image analysis with software ImageJ of calibrated sections of hair in certain areas of Shield (distal third of the hair towards the tip) and Shaft (proximal third of the hair towards the bulb). From the analysis of 90 hairs belonging to 15 female subjects (6 hairs to subject) attributable uniquely to the breeds Alpagota (3), Brogna (3), Foza (3), Lamon (3) and Appenninica (3), we have obtained 2 sets of 9023 raw data, in which are expressed values of area and perimeter of all cuticular forms (partial or total) referable to 6 sample areas contiguous 50 μm each. Since the objective is to identify a method of detection of the morphometric features and assuming that there are metric relations between the area and the perimeter of any geometric shape although not regular, it was decided to transform the values of area and perimeter of each form in its report "AREA/PERIMETER", obtaining a value expressed in microns. From each set of values it was then created a new set of index values equal to the average and median of the individual sample Shield and 6 areas of Shaft, bringing a contraction of the series of data sample of the population to 1080. These sample populations are considered in their entirety of the data, only considering data from the Shield area and only those relevant to the area of Shaft, subjected to parametric analysis of variance with procedure "Proc GLM SAS® version 9.2" and post- hoc test Duncan-Waller. The analysis showed that in all cases were always recognized the differences between the considered areas (Shield and Shaft), reflecting the fact that the method is able to adequately represent the microscopic obvious differences between the two areas of the hair. Considering then only the series of data relating to Shield and Shaft, it was possible to detect differences between breeds, with groupings "Foza-Alpagota", "Lamon" and "Brogna-Appenninica". About this, we can say that the features of micrometer diameter of wool in Brogna and Appenninica breeds are comparable, while the wool of Lamon breed is known to be larger in terms of length and diameter of the fibers. Only in the case of the analysis of the series on the medians in Shaft, with post-hoc test of Duncan-Waller it was possible to separate all five breeds. In summary, this method, if the results were confirmed by the application of the methods on a larger dataset in terms of number of individuals sampled, could be one possible economic method that integrates genetic analysis, also useful in the exploitation of the breeds by characterization (control and self-control) of derivatives

Growth Rate, Slaughter Traits and Meat Quality of Lambs of Three Alpine Sheep Breeds

A fattening and slaughter trial was carried out on 36 lambs of Alpagota, Brogna and Foza sheep breeds native of Veneto Region Alps (six male and six female lambs per breed) divided in three groups depending on the type of feed used: pasture, hay and concentrate, hay and concentrate supplemented with conjugated linoleic acid. Lambs were slaughtered at 225 days (mean weight: 30 kg). Infra-vitam and post-mortem data were analyzed by using a linear model that included the cross-classified effect of breed, sex, feeding system and age of lambs as linear covariate. The three breeds showed some specificity: Foza lambs, of both sexes, were larger-sized and faster growing, with a lower incidence of gastro-intestinal tract and lower cooking losses of the hind-leg samples compared to the other two middle-sized breeds. Alpagota breed tended to be leaner, with heavier shin and greater cooking losses than Brogna breed. In conclusion the three Alpine breeds of the Veneto Region confirmed to be able to produce lamb carcasses and meat with valuable characteristics that can be exploited through typical products and food preparation in local markets and gastronomy, according to the tradition. The valorisation of these productions can be an important instrument for in situ conservation of these breeds

Growth Rate, Slaughter Traits and Meat Quality of Lambs of Three Alpine Sheep Breeds

A fattening and slaughter trial was carried out on 36 lambs of Alpagota, Brogna and Foza sheep breeds native of Veneto Region Alps (six male and six female lambs per breed) divided in three groups depending on the type of feed used: pasture, hay and concentrate, hay and concentrate supplemented with conjugated linoleic acid. Lambs were slaughtered at 225 days (mean weight: 30 kg). Infra-vitam and post-mortem data were analyzed by using a linear model that included the cross-classified effect of breed, sex, feeding system and age of lambs as linear covariate. The three breeds showed some specificity: Foza lambs, of both sexes, were larger-sized and faster growing, with a lower incidence of gastro-intestinal tract and lower cooking losses of the hind-leg samples compared to the other two middle-sized breeds. Alpagota breed tended to be leaner, with heavier shin and greater cooking losses than Brogna breed. In conclusion the three Alpine breeds of the Veneto Region confirmed to be able to produce lamb carcasses and meat with valuable characteristics that can be exploited through typical products and food preparation in local markets and gastronomy, according to the tradition. The valorisation of these productions can be an important instrument for in situ conservation of these breeds

Conservazione e valorizzazione delle risorse genetiche animali autoctone

The conservation and enhancement of indigenous animal genetic resources is a field of theoretical study and application that are taking increasing interest and importance, especially in this new millennium in which global changes continue to accelerate and the need for sustainable and often localized agriculture, is becoming more prevalent (FAO, The State of Food and Agriculture, 2012, http://www.fao.org/catalog/inter-e.htm). The study of this thesis also financed by Veneto Region with a scholarship, is focused, through the presentation of four contributions, to the study of indigenous sheep genetic resources in Veneto region, with particular reference to the center of conservation at the Experimental Farm for the Mountain "Villiago" (Veneto Agriculture - Regional Agency for Agricultural sectors, Forestry and Food) Sedico (BL) (Annex I). The first contribution is about the characterization of Veneto sheep breeds with limited diffusion recognized in R.A. (Alpagota, Brogna, Foza and Lamon), through a genetic investigation with the use of a panel of 17 microsatellite markers (FASS, 1999; ISAG / FAO, 2004) and in relation to an Italian breed recognized in L.G. (Appenninica) used as an outgroup. To try to evaluate the influence of the structures of subpopulation (if present), total data were considered in the experimental plan in two ways: - as a single sample population ; - as two sample populations, divided into a main institutional farm called "main flock" ("Villiago"), which contains all 4 breeds of Veneto region, and into secondary farms called "secondary flocks" (essentially private breeders). In general, it was found that Veneto sheep breeds show a considerable genetic variability, in terms of number of alleles and heterozygosity with respect to the breed of reference, which proved to be the least variable (0.663). However, a significant deficit of heterozygotes was observed in every breed due to rather high levels of consanguinity or for the presence of substructures in the population, probably due to greater genetic variation in populations founders with respect to the latter. Considering the sample population divided into "main flock" and "secondary flocks," there has been a genetic differentiation between primary and secondary flocks within each breed, in terms of total number of alleles, allelic richness and reduction in genetic diversity. In general from total samples, not considering the division into "main flock" and "secondary flocks", the contribution of genetic diversity is between -0.954%, removing from the data set the Appenninica, to +1.357%, removing Alpagota. Considering the division between "main flock" and "secondary flocks", the results obtained from the main group are different from secondary groups: removing the subjects of "secondary flocks" the maximum value has been reached by removing the breeds Alpagota (-7.415) and Brogna (-6.390), while not considering breeds Foza and Lamon in both primary and secondary groups, the value obtained is always negative (Foza: -0.209, -6.237, Lamon: 0.949, -2.795, for "main flock" and "secondary flocks", respectively). In summary, the results of this study show the importance to compare the genetic diversity among primary and secondary flocks to safeguard native sheep breeds , especially in the guidelines that the institutions should provide in conservation programs to protect institutional and private farms, by providing separate and targeted actions. The results obtained are served, also, for the realization of a technical-informative layman for breeders (Annex II). The second contribution is to study the generational simulations through the use of Hybridlab software, in order to evaluate a first hypothesis about the possible effects of a selection of genotypes not susceptible to the development of neurodegenerative disease scrapie in native sheep breeds; the study concerns in particular the approach to generational simulations in groups of sheep that do not have the pedigree data. In this case the genetic variability of two groups of subjects from two native sheep breeds of Veneto region, Alpagota and Brogna (118 subjects in total, of which 23 ♂ and 42 ♀ for Brogna, 27 ♂ and 26 ♀ for Alpagota), was studied by genetic analysis with the application of 17 microsatellite markers, as in the protocol followed in the study of the first contribution of this work. The molecular data obtained were used for the simulation of subsequent generations of the two breeds, according to a scheme of intersections within the breed and on the basis of the choice of breeding males in relation to the genotypic data of scrapie susceptibility. The assumptions behind the work required for the coupling plane, were: - the allele frequencies of the sample of animals are representative of the original populations; - all rams and all females have the same reproductive performances; - males are selected by a random drawing and are used only for one round of mating; - the number of animals who makes up the sample population is fixed. For each breed were carried out four new simulated successive generations, expanding the population at time zero up to 1000 individuals and selecting more than 500 subjects representative of the real population (for allele frequencies and sex). On these simulated populations at time zero, considered representative of the real situation of departure, we proceeded to apply a selection scheme with internal selection of 10% of the internal real consistency, sex ratio of offspring about 50%, average fertility 145%, use of males for only one round of mating and never in reproductive round (season) after birth, but in the next. The selection, on the basis male, was performed using two different approaches: discarding males with scrapie unfavorable genotype (Hazard Class V genotypes VRQ / VRQ, ARQ / VRQ and ARH / VRQ) and without selection of the genotype. The subjects deleted were chosen randomly among those eligible for selection. It was found that the total number of alleles detected in Alpagota was of 158 (average 9:29 ± SD 2.95), and in Brogna was 186 (mean 10.94 ± SD 3.05). The differences in the mean number of alleles, expected and observed heterozygosity, and molecular coancestry are determined by the selected and non-selected populations of both breeds. The results showed that if the assumptions are met and the generational analysis is corrected by the use of Hybridlab software, selection against susceptibility to scrapie is possible in studied local breeds with reduced diffusion , without compromising the genetic diversity. The third contribution was made consecutive to the first two, and as a continuation of the same. It is based on molecular data of those animals tested in the first contribution and aims to try to answer two questions that a researcher might ask as a result of the theoretical analysis of generational simulation of populations: - "What would happen if there was in fact the direct and immediate removal of individuals as the result of a selection plan of subjects to high susceptibility to develop scrapie, and then in real populations?" - "Is possible to imagine a description of the current population at time zero?" To do this, we used data from real animals characterized in the first contribution of this thesis, extrapolating 394 individuals belonging to four Veneto sheep breeds, with the following specifications: 110 Alpagota, 186 Brogna, 55 and 43 Foza Lamon. In addition to the molecular characterization of 17 microsatellite markers, we have used the information from genotyping for verification of haplotype associated with the PrP gene, believed to be associated with the degree of susceptibility to developing the disease. So, I created 31 different punctual datasets, in relation to the removal of all combinations of haplotypes classified in the table of risk class indicated by the European Commission. The relative abundance of populations is different: - whole population (394 subjects); - population with removal of the male and female of risk class V (332 subjects); - population with subjects of risk class IV and V together (ie with complete removal of the VRQ allele from the population, for a total of 134 subjects). The statistical analysis of the datasets considered useful showed that the total number of alleles detected is equal to 286, with a minimum value of 11 for the loci McM527 and MAF65 and maximum value of 23 for the loci CSRD247 and INRA063. The allelic frequency relative to the alleles detected ARR, AHQ, ARK, ARQ, ARH and VRQ varies between breeds, but in all the ARQ allele is more prevalent. While the observed heterozygosity, passing from the analysis of data relating whole population to those of the other two populations without risk class V and risk class V and IV of individuals, would increase only in all cases for Brogna, for Lamon increases only between the last two categories, while for all breeds the average number of alleles drastically decreases. Finally, only the population of subjects of breed Lamon has reduced the loss in genetic diversity by comparing the three categories of dataset. In general, then, we can say that if we consider the selection of subjects in Veneto sheep breeds, in relation to the sampled data and assuming that these are representative of the real situation of entirely breeding populations, there is a possible general loss of biodiversity raised. In the fourth contribution, however, the conservation and development of animal genetic resources was investigated by an indirect approach, assuming that if there are glaring differences between individuals of different breeds and between breeds, there may also be differences expressed at the microscopic level. In this specific case it was decided to use a method of comparison of the wool, emphasizing the micro-morphometric structural features of hair surface, focusing on forms of cuticle. To try to reduce the error of the operator that should be adequately trained to recognize and classify the changing cuticular shapes, it has developed a method based on the measurement by microscopy image and subsequent image analysis with software ImageJ of calibrated sections of hair in certain areas of Shield (distal third of the hair towards the tip) and Shaft (proximal third of the hair towards the bulb). From the analysis of 90 hairs belonging to 15 female subjects (6 hairs to subject) attributable uniquely to the breeds Alpagota (3), Brogna (3), Foza (3), Lamon (3) and Appenninica (3), we have obtained 2 sets of 9023 raw data, in which are expressed values of area and perimeter of all cuticular forms (partial or total) referable to 6 sample areas contiguous 50 μm each. Since the objective is to identify a method of detection of the morphometric features and assuming that there are metric relations between the area and the perimeter of any geometric shape although not regular, it was decided to transform the values of area and perimeter of each form in its report "AREA/PERIMETER", obtaining a value expressed in microns. From each set of values it was then created a new set of index values equal to the average and median of the individual sample Shield and 6 areas of Shaft, bringing a contraction of the series of data sample of the population to 1080. These sample populations are considered in their entirety of the data, only considering data from the Shield area and only those relevant to the area of Shaft, subjected to parametric analysis of variance with procedure "Proc GLM SAS® version 9.2" and post- hoc test Duncan-Waller. The analysis showed that in all cases were always recognized the differences between the considered areas (Shield and Shaft), reflecting the fact that the method is able to adequately represent the microscopic obvious differences between the two areas of the hair. Considering then only the series of data relating to Shield and Shaft, it was possible to detect differences between breeds, with groupings "Foza-Alpagota", "Lamon" and "Brogna-Appenninica". About this, we can say that the features of micrometer diameter of wool in Brogna and Appenninica breeds are comparable, while the wool of Lamon breed is known to be larger in terms of length and diameter of the fibers. Only in the case of the analysis of the series on the medians in Shaft, with post-hoc test of Duncan-Waller it was possible to separate all five breeds. In summary, this method, if the results were confirmed by the application of the methods on a larger dataset in terms of number of individuals sampled, could be one possible economic method that integrates genetic analysis, also useful in the exploitation of the breeds by characterization (control and self-control) of derivatives.La conservazione e la valorizzazione delle risorse genetiche animali autoctone è un campo di studio teorico ed applicativo che sta assumendo sempre maggior interesse ed importanza, soprattutto in questo nuovo millennio in cui i cambiamenti globali sono sempre più rapidi e l’esigenza di un’agricoltura sostenibile e spesso localizzata si fa sempre maggiormente presente (FAO, 2012, The State of Food and Agriculture, http://www.fao.org/catalog/inter-e.htm). Lo studio riportato in questa tesi di dottorato, finanziato anche dalla Regione Veneto con una borsa di studio a tema vincolato, è stato focalizzato, attraverso la presentazione di quattro contributi, sullo studio delle risorse genetiche ovine autoctone del Veneto, con particolare riferimento al centro di conservazione presso l’Azienda Sperimentale per la Montagna “Villiago” (Veneto Agricoltura - Agenzia Regionale per i settori Agricolo, Forestale e Agroalimentare) di Sedico (BL) (Allegato I). Il primo contributo riguarda la caratterizzazione delle razze ovine venete a limitata diffusione iscritte a R.A. (Alpagota, Brogna, Foza e Lamon), attraverso un’indagine genetica con l’uso di un panel a 17 marcatori microsatelliti (FASS, 1999; ISAG/FAO, 2004) e in relazione ad una razza italiana iscritta a L.G. (Appenninica) usata come outgroup. Per cercare di valutare l’influenza delle strutture di sottopopolazione (se presenti), i dati totali sono stati considerati nel piano sperimentale in due modi: - come un’unica popolazione campionaria; - come due popolazioni campionarie, suddivise in un allevamento principale istituzionale definito “main flock”(“Villiago”) e che racchiude tutte e 4 le razze venete, e in allevamenti secondari definiti “secondary flocks”(essenzialmente allevatori privati). In generale, si è rilevato che le razze venete mostrano una considerevole variabilità genetica, in termini di numero di alleli e di eterozigosità, rispetto alla razza di riferimento, che si è rivelata la meno variabile (0.663). Tuttavia, un significativo deficit di eterozigoti è stato osservato in ogni razza a causa di livelli piuttosto elevati di consanguineità o per la presenza di sottostrutture nella popolazione, probabilmente dovute a una maggiore variabilità genetica nelle popolazioni fondatori rispetto a quest’ultime. Considerando poi la popolazione campionaria suddivisa in “main flock” e “secondary flocks”, si è assistito ad una differenziazione genetica tra greggi principali e secondarie all'interno di ogni razza, in termini di numero totale di alleli, ricchezza allelica e riduzione di diversità genetica (Caballero & Toro, 2002). In generale, dai campioni totali e non considerando la suddivisione in “main flock” e “secondary flocks”, il contributo della diversità genetica è compresa tra -0,954%, rimuovendo dal set di dati la razza Appenninica, a +1,357%, rimuovendo Alpagota. Considerando la suddivisione tra “main flock” e “secondary flocks”, i risultati ottenuti dal gruppo principale sono diversi da quelli dei gruppi secondari: rimuovendo i soggetti del “secondary flocks” il valore massimo si è raggiunto togliendo le razze Alpagota (-7,415) e Brogna (-6,390), mentre non considerando le razze Foza e Lamon in entrambi i gruppi principale e secondario, il valore ottenuto risulta sempre negativo (Foza: -0,209, -6,237, Lamon: 0,949, -2,795, per “main flock” e “secondary flocks”, rispettivamente). In sintesi, i risultati di questo studio mostrano quindi l'importanza di confrontare la diversità genetica tra le greggi principali e secondari per salvaguardare le razze ovine autoctone, soprattutto nell’ambito delle linee guide che le istituzioni dovrebbero fornire nei programmi di conservazione a tutela di allevamenti istituzionali e privati, prevedendo azioni distinte e mirate. I risultati ottenuti sono serviti, inoltre, per la realizzazione di una scheda tecnica informativo-divulgativa per gli allevatori (Allegato II). Nel secondo contributo si propone di studiare delle simulazioni generazionali attraverso l’uso del software Hybridlab, al fine di valutare una prima ipotesi sui possibili effetti di una selezione di genotipi non suscettibili allo sviluppo della malattia neurodegenerativa scrapie nelle razze ovine autoctone; lo studio riguarda in particolar modo l’approccio alle simulazioni generazionali in gruppi di ovini di cui non si possiedono i dati di pedigree. In questo caso la variabilità genetica di due gruppi di soggetti appartenenti a due razze ovine autoctone del Veneto, Alpagota e Brogna (118 soggetti totali, di cui 23 ♂ e 42 ♀ per Brogna, 27 ♂ e 26 ♀ per Alpagota), è stata studiata attraverso l’analisi genetica con l’applicazione di 17 marcatori microsatelliti, come nel protocollo seguito nello studio del primo contributo di questo lavoro. I dati molecolari ottenuti sono stati utilizzati per la simulazione delle generazioni successive delle due razze, secondo uno schema di incroci all'interno della razza e sulla base della scelta dei maschi riproduttori in relazione ai dati genotipici di suscettibilità scrapie. Gli assunti alla base del lavoro, necessari per il piano di accoppiamento, sono stati: - le frequenze alleliche degli animali del campione sono rappresentativi delle popolazioni originali; - tutti i montoni e le tutte femmine hanno le stesse prestazioni riproduttive; - i maschi sono selezionati da un disegno casuale e sono utilizzati solo per un turno di monte; - il numero di animali che compone la popolazione campione è fisso. Per ogni razza quattro nuove generazioni simulate successive sono state realizzate ampliando la popolazione al tempo zero fino a 1000 individui e selezionando oltre 500 soggetti rappresentativi della popolazione reale (per frequenze alleliche e sesso). Su queste popolazioni simulate al tempo zero, ritenute rappresentative della situazione reale di partenza, si è proceduto ad applicare uno schema di selezione con rimonta interna pari a 10% della consistenza reale, sex ratio della progenie 50% circa, prolificità media 145%, utilizzo dei maschi per un solo turno di monte e mai nel turno riproduttivo (stagione) successiva alla nascita, ma in quello dopo. La selezione, su base maschile, è stata eseguita utilizzando due diversi approcci: scartando maschi con genotipo scrapie sfavorevole (Classe di rischio V, genotipi VRQ/VRQ, ARQ/VRQ e ARH/VRQ) e senza selezione del genotipo. I soggetti eliminati sono stati scelti in maniera casuale tra quelli idonei alla selezione. Si è riscontrato che il numero totale di alleli rilevati in Alpagota è stato di 158 (media 9.29 ± SD 2.95), e in Brogna è stato di 186 (media 10.94 ± SD 3.05). Le differenze nel numero medio di alleli, eterozigosità attesa e osservata, e coancestry molecolare sono stati rilevati per le popolazioni selezionate e non selezionate di entrambe le razze. I risultati hanno mostrato che, se gli assunti sono rispettati e l’analisi generazionale è corretta con l’uso del software Hybridlab, la selezione contro la sensibilità alla scrapie è possibile nelle razze locali a ridotta diffusione studiate, senza compromettere la diversità genetica. Il terzo contributo è stato realizzato consecutivamente ai primi due e come continuazione degli stessi. Si basa sui dati molecolari dei soggetti animali analizzati nel primo contributo e ha come scopo cercare di rispondere a due domande che un ricercatore si potrebbe porre a seguito dell’analisi teorica di simulazione generazionale delle popolazioni: - "Cosa succederebbe se ci fosse in realtà la rimozione diretta ed immediata di individui a seguito di un di piano selezione dei soggetti a suscettibilità elevata di sviluppare la scrapie, e quindi nella popolazione reale?"; - "È possibile ipotizzare un quadro descrittivo della popolazione attuale al tempo zero?". Per fare questo, si sono utilizzati i dati reali degli animali caratterizzati nel primo contributo di questa tesi, estrapolando 394 soggetti appartenenti alle 4 razze ovine venete, con le seguenti specifiche: 110 Alpagota, 186 Brogna, 55 Foza e 43 Lamon. Oltre alla caratterizzazione molecolare a 17 marcatori microsatelliti, si sono utilizzate le informazioni derivanti dalla genotipizzazione per verifica dell’aplotipo associato al gene PrP, ritenuto associabile al grado di suscettibilità di sviluppo della malattia. Ho creato così 31 dataset puntuali differenti, in relazione alla rimozione di tutte le combinazioni di aplotipi inquadrati nella tabella di classe di rischio indicata dalla Commissione Europea. La numerosità delle popolazioni è però differente: - popolazione integra (394 soggetti); - popolazione con rimozione dei soggetti maschi e femmine iscrivibili nella classe di rischio V (332 soggetti); - popolazione con soggetti delle classi di rischio V e IV insieme (quindi con rimozione completa dell’allele VRQ dalla popolazione, per un totale di 134 soggetti). Dall’analisi statistica dei dataset ritenuti utili è emerso che il numero totale di alleli rilevato è pari a 286, con valore minimo di 11 pe

Pumpen - [tafeln n.] 4

Tavola numero 4 della collezione di Karl Bopp, professore di fisica a Stoccarda (1833-1904). Rappresenta una pompa per acqu

The ecological behaviour of one Apodemus spp. population in the area of Villiago, Triva, Pasa (Belluno, Italy).

Aims: In this research the ecological behavior of a population of Apodemus spp. living in the East North of Italy (Veneto, Italy) is analyzed. In this specific instance, we tried to evalutate the activity of the animals as regards meteorological variabilities and the exact hour of capture of three congenerouses Apodemus agrarius (Pallas, 1771), Apodemus flavicollis (Melchior, 1834) and Apodemus sylvaticus (Linneus, 1758), with special reference to the component given by the wild Striped Field Mouse, in a purely agricultural area, situated in the commune of Sedico (Belluno, Veneto) and inserted in the phytoclimatic Esalpico district. Following the preliminary study which was intended to define the check-list of the microteriofauna living in the area of study in connection to the present environmental typologies, it has been decided to examine in the period March - December 2004 the fauna component given by the three kinds of Apodemus spp. in defined a sub-area of 1 ha surface, composed by particles with different soil and various vegetation coverage where the three species are coexistent

Dati sui micromammiferi della pianura vicentina (Sandrigo, VI) dall'analisi di borre di strigiformi e falconiformi. Data on micromammals of the Vicenza plain (Sandrigo, NE Italy)obtained from Strigiformes and Falconiformes pellet analysis.

Aims: Between May 2005 and March 2006, 405 pellets of both diurnal and nocturnal raptors have been collected from 5 sites near Sandrigo (Vicenza). Through the examination of bone remains within the pellets, 12 species of micromammals and one bat could be identified. Among them, Sorex arunchi, Microtus liechtensteini and Micromys minutus hold a special interest