172 research outputs found
Confirmation of the association between a single nucleotide polymorphism in the porcine LDHA gene and average daily gain and correlated traits in Italian Large White pigs
No full textThe lactate dehydrogenase A (LDHA) gene encodes for an enzyme predominantly expressed in skeletal muscle where it catalyses the recycling reaction of L-lactate in the final step of the anaerobic glycolysis. This gene is localized on porcine chromosome 2 (SSC2) where several reports have also localized QTLs for carcass traits and growth rate. We identified that a single nucleotide polymorphism (SNP) in exon 3 of the porcine LDHA gene (AJ557234:g.46G>T) was associated with average daily gain (ADG) in Italian Large White pigs. We herein confirm our previous results analysing this marker in a larger number of animals using a selective genotyping approach based on extreme and divergent estimated breeding values (EBV) for ADG and evaluated the effects of the g.46G>T SNP on EBV for several other traits (back fat thickness, BFT; feed:gain ratio, FGR; ham weight, HW; and lean cut content, LC)
On the use of Elo rating on harness racing results in the genetic evaluation of trotter
No full textThe official results of trotters in Italian harness racings have been used to get AM-BLUP estimates
of genetic parameters, EBVs and rTI of three groups of traits: speed (racing time, annual best time,
best time in career between 2- and 5-year old), earnings (earnings/start, annual earnings, total
earnings between 2- and 5-year old) and Elo system traits (underlying performance and final
rating). The Elo system has been used for half a century in chess players rating, and it has been
modified and fitted to several games and sports: it has already been used for genetic evaluation of
sport horses in France. The highest heritability estimates in each group of traits have been found for
best time (.430±.014), total earnings (.271±.013) and Elo final rating (.270±.008). The choice of
“k”, the Elo ratings updating factor, did not show a key role in affecting the results. The underlying
performance heritability and repeatability have been estimated .159±.004 and .420±.007
respectively. The Elo-based systems proved to be very promising in objectively evaluating trotters
Density Tapering of Linear Arrays Radiating Pencil Beams: A New Extremely Fast Gaussian Approach
No full textIn this communication, a very simple and extremely fast algorithm is proposed for the pencil beam synthesis of linear sparse arrays having uniform distribution of the excitations. The key idea is that of selecting, as a desired pattern, a Gaussian function having small standard deviation, so as to obtain a narrow beam. This immediately provides the excitation density of the corresponding continuous array of infinite length. Starting from this result and considering a linear array of length L with N elements having equal excitations, an extremely fast and accurate algorithm based on a density tapering approach is proposed that yields suitable positions of the elements, in such a way as to provide an array factor that well approximates the desired pattern. Numerical examples are presented to show the effectiveness of the developed procedure, also when compared with state-of-the-art algorithms. The proposed approach does not consider the mutual coupling between the array elements, but it is numerically shown that this effect produces quite acceptable degradation on the synthesized patterns. Finally, it is shown that also problems involving thousands of elements can be solved in a very accurate way in few milliseconds
Association between cathepsin L (CTSL) and cathepsin S (CTSS) polymorphisms and meat production and carcass traits in Italian Large White pigs.
No full textThe aim of this work was to identify and analyse DNA markers in two cathepsin genes, cathepsin L (CTSL) and cathepsin S (CTSS), and study their association with meat quality parameters (including cathepsin activity of post mortem muscle) and several production traits in Italian Large White pigs. In silico analysis of the porcine CTSL and CTSS genes identified two new single nucleotide polymorphisms (SNPs), one located in exon 5 (CTSL) and one positioned in the 5'-untranslated region (CTSS). Allele frequencies of these two SNPs were evaluated in 7 different pig breeds. In addition, radiation hybrid mapping localized the CTSS gene on porcine chromosome 4, in an important QTL region for meat and fat deposition. Association analysis with meat quality traits, carried out in 268 Italian Large White pigs, indicated association of the CTSL polymorphism with average daily gain (ADG), weight of lean cuts (LC) and back fat thickness (BFT) estimated breeding values (P<0.05). Results for LC and BFT were also confirmed using a selective genotyping approach in other Italian Large White pigs (P<0.01). In the 268 Italian Large White pigs, the CTSS polymorphism was associated with feed:gain ratio and ADG (P<0.05). No association was observed between the analysed markers and meat quality parameters (pH(1), pH(u), lactate, glycogen, glycolytic potential and cathepsin activity, all measured on Musculus semimembranosus). Overall these results, together with those previously reported for other genes of this family, suggest that cathepsin genes play a role in defining economically important traits in pigs. Copyright 2010 Elsevier Ltd. All rights reserved
Association between polymorphisms in cathepsin and cystatin genes with meat production and carcass traits in Italian Duroc pigs: confirmation of the effects of a cathepsin L (CTSL) gene marker
No full textWe genotyped single nucleotide polymorphisms (SNPs) in 5 cathepsin or cystatin genes (cathepsin F, CTSF; cathepsin L, CTSL; cathepsin S, CTSS; cathepsin Z, CTSZ; cystatin B, CSTB) in two groups of Italian Duroc pigs: the first group (n. 100) was chosen using a selective genotyping approach with extreme estimated breeding value (EBV) for visible intermuscular fat (VIF); the second group (n. 218) was made of performance-tested Duroc pigs not selected by any criteria. CTSL marker showed a tendency towards association (P < 0.10) with VIF (first group) and back fat thickness (BFT) and average daily gain (ADG; second group). In the second group, the CTSL polymorphism was associated with weight of lean cuts (LC; P < 0.05). Additive effects for all mentioned traits in the second group was significant (P < 0.05). The results we obtained in the Italian Duroc pigs confirmed the results and the direction of the effects already reported for the Italian Large White breed
A selective genotyping approach identifies single nucleotide polymorphisms in porcine chromosome 2 genes associated with production and carcass traits in Italian heavy pigs.
No full textSeveral studies have shown that porcine chromosome 2 (SSC2) harbors important quantitative trait loci (QTL) for production traits. In particular, an imprinted QTL for muscle mass production is determined by a mutation in the IGF2 gene (intron3-g.3072G>A). We recently identified and analysed single nucleotide polymorphisms (SNPs) in genes (cathepsin D, CTSD g.70G>A; cathepsin F, CTSF g.22G>C; lactate dehydrogenase A, LDHA g.46G>T) localized on SSC2 (including the IGF2 intron3-g.3072G>A SNP) showing association with production traits in Italian Large White pigs and/or localizing them on QTL regions. Here we analysed these markers applying a selective genotyping approach based on estimated breeding values (EBVs). Three groups of Italian Large White pigs each made by animals with the most positive (n. 50) and most negative (n. 50) EBVs for average daily gain (ADG), backfat thickness (BFT) or weight of lean cuts (LC) and one group of Italian Duroc pigs made by 50 animals with most positive and 50 animals with most negative EBV for visible intermuscular fat (VIF) were genotyped. In Italian Large White pigs, allele frequency differences for the IGF2 intron3-g.3072G>A SNP between the two extreme tails for all groups were highly significant (considering all analysed animals: P=9.85E-20 for LC; P=3.16E-15 for BFT; P=4.41E-6 for ADG). Significant allele frequency differences were also observed for the CTSD g.70G>A (P=0.0002 for ADG; P=0.00068) and LDHA g.46G>T (P=2.32E-5 for ADG) polymorphisms. These results provide further support on the effects of these polymorphisms or genes whose application on marker assisted selection programs could be envisaged
Selezione tradizionale e assistita da marcatori nei suini
No full textLa selezione italiana si distingue da quella di tutti gli altri Paesi perché è indirizzata alla produzione di un suino pesante che fornisca tagli e carne idonei per la trasformazione in salumi di alto pregio.
Il piano di selezione nazionale attivato dall’Associazione Italiana Allevatori Suini (ANAS) nei primi anni ’60 con la vigilanza dell’allora Ministero dell’Agricoltura si basa su due capisaldi: il Libro Genealogico e i centri di controllo genetico dei verri. Questa impostazione generale non è più cambiata, ma sulla base delle nuove conoscenze messe a disposizione dalla ricerca scientifica, è stata continuamente migliorata negli obiettivi e nei criteri di selezione, nei metodi di valutazione dei riproduttori, negli strumenti e nell’organizzazione per renderla sempre più adeguata alle esigenze della filiera di produzione dei salumi italiani. Al 1990 risale l’ultima revisione importante, che ha finalizzato la selezione in modo più stringente alla qualità della carne, intesa essenzialmente come attitudine alla trasformazione in prosciutto di Parma e di San Daniele. Infatti, ai classici criteri di selezione riguardanti l’economia di produzione e l’eliminazione del gene alotano, sono stati affiancati due nuovi criteri specifici per la valutazione della qualità della carne: il calo di prima salatura correlato con quello di stagionatura e il GIV (grasso inter-ed intra muscolare visibile). Inoltre per lo spessore del lardo dorsale non si persegue più una riduzione ma il mantenimento dell’attuale livello presente nelle razze per assicurare la necessaria copertura adiposa del prosciutto.
I risultati ottenuti a 15 anni dall’applicazione completa con il nuovo schema di selezione sono molto buoni, come dimostra il trend molto positivo per tutti gli obiettivi di selezione e il confronto tra le suddette caratteristiche della carne dei suini provenienti dalla selezione nazionale rispetto a quelli derivate da schemi di selezione stranieri.
L’avvento della genetica molecolare ha messo a disposizione nuovi strumenti per aumentare l’efficienza della selezione, perché può permettere il superamento dei limiti di quella tradizionale: antagonismo quantità qualità, difficoltà di rilevazione e bassa ereditabilità di alcune caratteristiche, quali, ad esempio, l’efficienza riproduttiva e la resistenza alle malattie. Inoltre può migliorare l’accuratezza della stima del valore genetico dei riproduttori e l’intensità di selezione e ridurre l’intervallo tra le generazione, aumentando e velocizzando il progresso genetico.
Con l’enorme sviluppo della genetica molecolare che ha permesso la mappatura del genoma suino sono stati messi a disposizione gli strumenti di base che hanno portato all’identificazione di un elevato numero di QTL e geni con effetto fenotipico importante, alcuni dei quali di particolare interesse per la specificità della suinicoltura italiana.
Le conoscenze acquisite hanno già dato origine ad importanti applicazioni. In futuro si attendono applicazioni ancora più importanti dall’aumento delle conoscenze, che dovrebbe portare alla completa decifrazione del DNA del genoma suino e dall’integrazione di queste con i metodi di selezione tradizionale. Bisogna tuttavia sottolineare che già adesso l’utilizzo, ai fini della selezione, delle mutazioni in molti geni con effetto rilevante sulle produzioni è molto spesso coperto da brevetti stranieri
The porcine fat mass and obesity associated (FTO) gene is associated with fat deposition in Italian Duroc pigs.
No full textIn humans, common variants in the fat mass and obesity associated (FTO) gene are associated with body mass index and obesity. Here we sequenced exon 4, parts of introns 3 and 4 and two portions of the 3'-untranslated region of the porcine FTO gene in a panel of nine pigs of different breeds and identified three SNPs.
Allele frequencies of the g.276T>G (AM931150) mutation were studied in seven pig breeds. This mutation was used to linkage-map FTO to SSC6. Association analyses between the g.276T>G polymorphism and several traits [pH of semimembranosus
muscle and estimated breeding values (EBV) for average daily gain, back fat thickness, lean cuts, ham weight and feed:gain ratio] were carried out in 257 sib-tested Italian Large White pigs. Only feed:gain ratio showed P<0.05. A selective genotyping approach was applied, analysing two extreme and divergent groups of Italian Large White pigs selected on the basis of back fat thickness
EBV (50 with most positive and 50 with most negative values). Fisher's exact test (two-tailed) was not significant when comparing the allele frequencies of these two groups. The same approach was used in the Italian Duroc breed for which two extreme and divergent groups of animals were selected according to visible
intermuscular fat EBV. Differences of allele frequencies between these two groups were highly significant (P<0.00001, P<0.001 and P<0.0001, considering all animals or only two- or three-generation unrelated animals respectively), indicating association between the analysed FTO marker and intermuscular fat deposition
Analysis of association between a microsatellite at intron 1 of the insulin-like growth factor 1 (IGF1) gene and fat deposition, meat production and quality traits in Italian Large White and Italian Duroc pigs
No full textIl legame tra un prodotto di origine animale e la razza da cui questo è originato rappresenta un aspetto importante per la valorizzazione di alcune produzioni. Il maggior prezzo che questi prodotti spuntano sul mercato fa emergere l’esigenza di poter autenticare o tracciare i prodotti mono-razza per smascherare e scoraggiare possibili frodi. A questo scopo sono stati proposti sistemi di analisi del DNA, alcuni dei quali utilizzano marcatori in geni che determinano il colore del mantello, che è uno dei principali caratteri che differenziano tra di loro le razze. Diverse mutazioni nel gene melanocortin 1 receptor (MC1R) sono già state associate a particolari effetti sul colore del mantello nella specie bovina. In questa ricerca abbiamo studiato la presenza dei principali alleli al locus MC1R, per valutare la possibilità di utilizzare questo gene per l’autenticazione e la tracciabilità di razza dei prodotti lattiero-caseari. Le mutazioni che permettono di distinguere questi alleli sono state analizzate utilizzando protocolli di PCR-RFLP e PCR-APLP su un totale di 1360 animali appartenenti a 18 razze bovine. Per ognuna delle seguenti razze, Frisona Italiana, Bruna Italiana, Pezzata Rossa Italiana, Jersey, Rendena, Reggiana e Modenese, è stato possibile analizzare più di 70 animali. L’allele Ed è stato identificato nella razza Frisona Italiana con una frequenza dello 0,886. L’allele E (nomenclatura che include tutti gli alleli tranne che e, Ed e E1) è stato identificato con alta frequenza nella Bruna Italiana (0,591), Rendena (0,738), Jersey (0,955) e Modenese (0,961) e con bassa frequenza nella Pezzata Rossa Italiana (0,029). Inoltre, questo allele è stato osservato nella Rossa Svedese, Rossa Danese, Grigio Alpina, Piemontese, Romagnola, Marchigiana e Chianina. In alcune di queste razze (Bruna Italiana, Rendena, Grigio Alpina, Piemontese, Rossa Svedese e Rossa Danese) è stato identificato anche l’allele E1. L’allele e è risultato fissato nella razza Reggiana e quasi fissato nella razza Pezzata Rossa Italiana. Inoltre, con bassa frequenza, è stato identificato in tutte le altre razze analizzate, tranne che nella Marchigiana. Le differenze osservate tra razze esaminate indicano che, almeno in alcuni casi, è possibile utilizzare i polimorfismi del gene MC1R per escludere o confermare l’impiego di latte di una determinata razza nella produzione di un prodotto lattiero-caseario. Il caso più interessante è quello del formaggio Parmigiano Reggiano prodotto con l’uso esclusivo di latte di bovine di razza Reggiana. Infatti, essendo presente in questa razza soltanto l’allele e il rilievo analitico di qualsiasi altro allele nel DNA estratto dal formaggio rivela l’uso di latte proveniente da altre razze. La messa a punto di un metodo PCR-RFLP per l’analisi del DNA estratto da prodotti lattiero caseari, incluso il Parmigiano Reggiano di oltre 24 mesi di stagionatura, rappresenta uno strumento importante per la difesa di questo prodotto mono-razza da eventuali frodi. I risultati ottenuti su 10 forme di formaggio prodotto esclusivamente con latte di bovine di razza Reggiana e su 15 forme di Parmigiano Reggiano commerciale ottenuto senza restrizione della razza di origine del latte hanno mostrato la validità del metodo del quale è stata valutata anche la sensibilitàA few studies have shown that a microsatellite at intron 1 of the insulin-like growth factor 1 (IGF.1) gene is associated with several production traits in a few pig populations. In the current work we evaluated associations between this microsatellite and production traits in Italian Large White and Italian Duroc pigs. Association studies were carried out on a total of 1120 animals using two experimental designs: i) a selective genotyping approach based on extreme and divergent Italian Large White pigs for back fat thickness (BFT) estimated breeding value (EBV) or on extreme and divergent Italian Duroc pigs for visible inter-muscular fat (VIF) EBV; and ii) analysis of unselected pigs (random groups) coming from populations of the two breeds. Allele distributions between Italian Large White and Italian Duroc pigs were different (P<0.05) with longer alleles being more frequent in Italian Large White. Results of the association analyses from two different random groups showed that this marker affects average daily gain EBV, lean cut EBV and BFT EBV in Italian Large White and BFT EBV in Italian Duroc (P<0.05). Association analysis carried out with random residuals confirmed, to some extent (P=0.096), the effects on BFT in the same animals. However, this result was not confirmed in the two extreme and divergent Italian Large White groups used in the selective genotyping exper- iment. These inconsistent results may indicate that the effect of the IGF1 microsatellite is doubtful in the investigated finishing pigs
Study of porcine adiponectin (ADIPOQ) gene and association of a missense mutation with EBVs for production and carcass traits in Italian Duroc heavy pigs
No full textThe adiponectin (adiponectin, C1Q and collagen domain containing) encoded by ADIPOQ is adipokine that modulates several biological processes such as lipogenesis, gluconeogenesis, fatty acid oxidation, glucose uptake and insulin sensitivity. An objective of this study was to identify SNPs in the ADIPOQ gene both in cosmopolitan and local pig breeds reared in Italy and in Meishan samples. Resequencing of ADIPOQ gene regions in 16 pigs of 12 breeds revealed only two SNPs (EU489740:g.1611G>A synonymous and the EU489740:g.1735G>A missense mutations) already reported. The g.1735G>A polymorphism was genotyped by PCR-RFLP in 510 pigs from 11 breeds reared in Italy (Italian Large White, Italian Duroc, Italian Landrace, Belgian Landrace, Hampshire, Pietrain, Calabrese, Casertana, Cinta Senese, Mora Romagnola and Nero Siciliano) and from Chinese Meishan breed. The Italian local breeds were homozygous for the g.1735G allele while the Meishan samples resulted homozygous for the g.1735A allele. The polymorphism segregates in the cosmopolitan breeds, except for Hampshire, and the rarer g.1735A allele showed the highest frequency in Italian Duroc (0.12). Association analysis of g.1735G>A polymorphism with estimated breeding values (EBVs) for average daily gain (ADG), feed:gain ratio (FGR), weight of neck and loin (lean cuts, LC), weight of ham (H) and backfat thickness (BFT) were performed in Italian Duroc heavy pigs. The GA vs GG pigs showed higher least square means for ADG (P= 0.003) and LC (P= 0.036) EBVs and lower value for FGR EBV (P= 0.033)
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