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[EN] Deoxyribonucleic acid (DNA) can be extracted from different tissue sources. The most common is blood, but in some situations it can be easier to take a biopsy. In some cases when it is difficult to capture animals, especially in wild populations, faeces and hairs can be considered as a source of DNA. This paper presents a pilot study conducted to compare the applicability of invasive and non-invasive sampling methods for extracting DNA for use in genetic studies of rabbits (Oryctolagus cuniculus). The study included 24 rabbits from the INRA 1001 strain. Blood, hair, ear biopsies and faeces were collected and used as DNA sources. Our aim was to verify the quantity of DNA obtained from different tissues using two or three types of extraction. DNA was obtained for all tissue types and all extraction methods. DNA extraction was shown to be optimal with the LGC (Laboratory of Cellular Genetics) blood extraction method. With regard to non-invasive methods, DNA extraction for hair using the LGC protocol and QIAamp¿ DNA mini kit gave very low quantities of DNA that could not be used for PCR reactions. The Chelex extraction protocol gave good results for PCR but could not be quantified. DNA extracted from faeces is a viable source of DNA for determining individual genotypes. The use of such non-invasive samples as a source of genetic material is a recent and very promising technique, especially for the study of endangered species, but these techniques are still too unreliable and costly to altogether replace invasive techniques when the latter are possible.

[EN] Deoxyribonucleic acid (DNA) can be extracted from different tissue sources. The most common is blood, but in some situations it can be easier to take a biopsy. In some cases when it is difficult to capture animals, especially in wild populations, faeces and hairs can be considered as a source of DNA. This paper presents a pilot study conducted to compare the applicability of invasive and non-invasive sampling methods for extracting DNA for use in genetic studies of rabbits (Oryctolagus cuniculus). The study included 24 rabbits from the INRA 1001 strain. Blood, hair, ear biopsies and faeces were collected and used as DNA sources. Our aim was to verify the quantity of DNA obtained from different tissues using two or three types of extraction. DNA was obtained for all tissue types and all extraction methods. DNA extraction was shown to be optimal with the LGC (Laboratory of Cellular Genetics) blood extraction method. With regard to non-invasive methods, DNA extraction for hair using the LGC protocol and QIAamp¿ DNA mini kit gave very low quantities of DNA that could not be used for PCR reactions. The Chelex extraction protocol gave good results for PCR but could not be quantified. DNA extracted from faeces is a viable source of DNA for determining individual genotypes. The use of such non-invasive samples as a source of genetic material is a recent and very promising technique, especially for the study of endangered species, but these techniques are still too unreliable and costly to altogether replace invasive techniques when the latter are possible.

[EN] Deoxyribonucleic acid (DNA) can be extracted from different tissue sources. The most common is blood, but in some situations it can be easier to take a biopsy. In some cases when it is difficult to capture animals, especially in wild populations, faeces and hairs can be considered as a source of DNA. This paper presents a pilot study conducted to compare the applicability of invasive and non-invasive sampling methods for extracting DNA for use in genetic studies of rabbits (Oryctolagus cuniculus). The study included 24 rabbits from the INRA 1001 strain. Blood, hair, ear biopsies and faeces were collected and used as DNA sources. Our aim was to verify the quantity of DNA obtained from different tissues using two or three types of extraction. DNA was obtained for all tissue types and all extraction methods. DNA extraction was shown to be optimal with the LGC (Laboratory of Cellular Genetics) blood extraction method. With regard to non-invasive methods, DNA extraction for hair using the LGC protocol and QIAamp¿ DNA mini kit gave very low quantities of DNA that could not be used for PCR reactions. The Chelex extraction protocol gave good results for PCR but could not be quantified. DNA extracted from faeces is a viable source of DNA for determining individual genotypes. The use of such non-invasive samples as a source of genetic material is a recent and very promising technique, especially for the study of endangered species, but these techniques are still too unreliable and costly to altogether replace invasive techniques when the latter are possible.

[EN] Deoxyribonucleic acid (DNA) can be extracted from different tissue sources. The most common is blood, but in some situations it can be easier to take a biopsy. In some cases when it is difficult to capture animals, especially in wild populations, faeces and hairs can be considered as a source of DNA. This paper presents a pilot study conducted to compare the applicability of invasive and non-invasive sampling methods for extracting DNA for use in genetic studies of rabbits (Oryctolagus cuniculus). The study included 24 rabbits from the INRA 1001 strain. Blood, hair, ear biopsies and faeces were collected and used as DNA sources. Our aim was to verify the quantity of DNA obtained from different tissues using two or three types of extraction. DNA was obtained for all tissue types and all extraction methods. DNA extraction was shown to be optimal with the LGC (Laboratory of Cellular Genetics) blood extraction method. With regard to non-invasive methods, DNA extraction for hair using the LGC protocol and QIAamp¿ DNA mini kit gave very low quantities of DNA that could not be used for PCR reactions. The Chelex extraction protocol gave good results for PCR but could not be quantified. DNA extracted from faeces is a viable source of DNA for determining individual genotypes. The use of such non-invasive samples as a source of genetic material is a recent and very promising technique, especially for the study of endangered species, but these techniques are still too unreliable and costly to altogether replace invasive techniques when the latter are possible.

Background: Many QTL have been detected in pigs, but very few of them have been fine-mapped up to the causal mutation. On SSC2, the IGF2-intron3-G3072A mutation has been described as the causative polymorphism for a QTL underlying muscle mass and backfat deposition, but further studies have demonstrated that at least one additional QTL should segregate downstream of this mutation. A marker-assisted backcrossing design was set up in order to confirm the segregation of this second locus, reduce its confidence interval and better understand its mode of segregation. Results: Five recombinant full-sibs, with genotype G/G at the IGF2 mutation, were progeny-tested. Only two of them displayed significant QTL for fatness traits although four inherited the same paternal and maternal chromosomes, thus exhibiting the same haplotypic contrast in the QTL region. The hypothesis of an interaction with another region in the genome was proposed to explain these discrepancies and after a genome scan, four different regions were retained as potential interacting regions with the SSC2 QTL. A candidate interacting region on SSC13 was confirmed by the analysis of an F2 pedigree, and in the backcross pedigree one haplotype in this region was found to mask the SSC2 QTL effect. Conclusions: Assuming the hypothesis of interactions with other chromosomal regions, the QTL could be unambiguously mapped to a 30 cM region delimited by recombination points. The marker-assisted backcrossing design was successfully used to confirm the segregation of a QTL on SSC2 and, because full-sibs that inherited the same alleles from their two parents were analysed, the detection of epistatic interactions could be performed between alleles and not between breeds as usually done with the traditional Line-Cross model. Additional analyses of other recombinant sires should provide more information to further improve the fine-mapping of this locus, and confirm or deny the interaction identified between chromosomes 2

Le programme " Genecan " de recherche de QTL a été initié en 2004 à l'INRA pour rechercher les zones chromosomiques ayant un effet sur les caractères liés au gavage et la qualité des produits qui en découle, dans une population Back-Cross (BC) de canards communs. L'analyse des données de performances des descendants mulards gavés de ces canes BC a permis, par cartographie d'intervalle à l'aide du logiciel QTLMap, de détecter 73 QTL affectant principalement la croissance des animaux, les taux de glucose, cholestérol et triglycérides sanguins circulant durant le gavage, la couleur du foie, la composition lipidique du foie et des magrets et leurs caractéristiques technologiques (taux de fonte du foie, pH et pertes à la cuisson du magret).

Le programme " Genecan " de recherche de QTL a été initié en 2004 à l'INRA pour rechercher les zones chromosomiques ayant un effet sur les caractères liés au gavage et la qualité des produits qui en découle, dans une population Back-Cross (BC) de canards communs. L'analyse des données de performances des descendants mulards gavés de ces canes BC a permis, par cartographie d'intervalle à l'aide du logiciel QTLMap, de détecter 73 QTL affectant principalement la croissance des animaux, les taux de glucose, cholestérol et triglycérides sanguins circulant durant le gavage, la couleur du foie, la composition lipidique du foie et des magrets et leurs caractéristiques technologiques (taux de fonte du foie, pH et pertes à la cuisson du magret).

Background - The resolution of radiation hybrid (RH) maps is intermediate between that of the genetic and BAC (Bacterial Artificial Chromosome) contig maps. Moreover, once framework RH maps of a genome have been constructed, a quick location of markers by simple PCR on the RH panel is possible. The chicken ChickRH6 panel recently produced was used here to construct a high resolution RH map of chicken GGA5. To confirm the validity of the map and to provide valuable comparative mapping information, both markers from the genetic map and a high number of ESTs (Expressed Sequence Tags) were used. Finally, this RH map was used for testing the accuracy of the chicken genome assembly for chromosome 5. Results - A total of 169 markers (21 microsatellites and 148 ESTs) were typed on the ChickRH6 RH panel, of which 134 were assigned to GGA5. The final map is composed of 73 framework markers extending over a 1315.6 cR distance. The remaining 61 markers were placed alongside the framework markers within confidence intervals. Conclusion - The high resolution framework map obtained in this study has markers covering the entire chicken chromosome 5 and reveals the existence of a high number of rearrangements when compared to the human genome. Only two discrepancies were observed in relation to the sequence assembly recently reported for this chromosome.