AGRICULTURE: Scientific and Professional Review (; Vol.13 No.1 01/2007;
Source: OAI


Genetic relationships among four Veneto native breeds of chickens were studied on the basis of microsatellites polymorphisms. A total of 190 DNA samples (45 Robusta Lionata, 43 Robusta Maculata, 45 Ermellinata di Rovigo, 45 Pèpoi) and a commercial broiler line (12 Golden Comet) were genotyped at 20 microsatellite loci. The average number of alleles per locus was 5 and the expected heterozygosity resulted lower for the local breeds than for the commercial broiler line used as reference. The inbreeding coefficient showed a deficit of heterozygotes, highest for the Robusta Lionata breed. Nei’s standard genetic distances corrected for bias due to sampling of individuals (Da), based on allele frequencies, and Reynolds distances (DReynolds) were calculated among breeds. The Robusta Lionata and Robusta Maculata resulted very similar approving the same genetic origin. A Neighbor-Joining tree drawn from DReynolds distances clustered three groups, one including the Robusta Lionata and Robusta Maculata breeds, the second one formed by the Ermellinata di Rovigo and the Golden Comet commercial line and the third by the Pèpoi. The results showed the genetic differences occurring between the local chicken breeds.

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    • "Tadano et al., 2012), reflecting excess heterozygosity. In contrast, Italian chicken breeds (0.042; Zanetti et al., 2007) and 15 Chinese indigenous chicken breeds (0.02; Chen et al., 2008) had positive and higher values of F IS , indicating heterozygosity deficiency and departures from random mating as a result of inbreeding within populations. As Edea et al. (2013) suggested, the absence of any significant inbreeding effects may be a reflection of the high gene flow between the populations, as supported by high Nm values (Table S1), the large population from which the samples were drawn, and the fact that related individuals were purposely avoided. "
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    ABSTRACT: In total, 246 individuals from 8 Chinese indigenous blue- and brown-shelled chicken populations (Yimeng Blue, Wulong Blue, Lindian Blue, Dongxiang Blue, Lushi Blue, Jingmen Blue, Dongxiang Brown, and Lushi Brown) were genotyped for 21 SNP markers from the SLCO1B3 gene to evaluate phylogenetic relationships. As a representative of nonblue-shelled breeds, White Leghorn was included in the study for reference. A high proportion of SNP polymorphism was observed in Chinese chicken populations, ranging from 89% in Jingmen Blue to 100% in most populations, with a mean of 95% across all populations. The White Leghorn breed showed the lowest polymorphism, accounting for 43% of total SNPs. The mean expected heterozygosity varied from 0.11 in Dongxiang Blue to 0.46 in Yimeng Blue. Analysis of molecular variation (AMOVA) for 2 groups of Chinese chickens based on eggshell color type revealed 52% within-group and 43% between-group variations of the total genetic variation. As expected, FST and Reynolds' genetic distance were greatest between White Leghorn and Chinese chicken populations, with average values of 0.40 and 0.55, respectively. The first and second principal coordinates explained approximately 92% of the total variation and supported the clustering of the populations according to their eggshell color type and historical origins. STRUCTURE analysis showed a considerable source of variation among populations for the clustering into blue-shelled and nonblue-shelled chicken populations. The low estimation of genetic differentiation (FST) between Chinese chicken populations is possibly due to a common historical origin and high gene flow. Remarkably similar population classifications were obtained with all methods used in the study. Aligning endogenous avian retroviral (EAV)-HP insertion sequences showed no difference among the blue-shelled chickens. © 2015 Poultry Science Association Inc.
    Poultry Science 06/2015; 94(8). DOI:10.3382/ps/pev146 · 1.67 Impact Factor
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    • "By increasing the number of loci used to 24, accuracy was close to 97% (Rosenberg et al. 2001). Furthermore, small-scale studies analysing only a few local Italian or Japanese fancy breeds showed that these breeds can be genetically identified and that they generally display low genetic diversity (Tadano et al. 2007, 2008; Zanetti et al. 2007). For 28 of the 30 FAO-recommended microsatellite markers , data for around 100 breeds are currently published. "
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    ABSTRACT: Domestication of livestock species and a long history of migrations, selection and adaptation have created an enormous variety of breeds. Conservation of these genetic resources relies on demographic characterization, recording of production environments and effective data management. In addition, molecular genetic studies allow a comparison of genetic diversity within and across breeds and a reconstruction of the history of breeds and ancestral populations. This has been summarized for cattle, yak, water buffalo, sheep, goats, camelids, pigs, horses, and chickens. Further progress is expected to benefit from advances in molecular technology.
    Animal Genetics 05/2010; 41 Suppl 1(Suppl 1):6-31. DOI:10.1111/j.1365-2052.2010.02038.x · 2.21 Impact Factor
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    ABSTRACT: In common domestic species for which varieties, strains or breeds are in danger of extinction, the population levels at which action needs to be taken are object of research in many countries. Different approaches have been developed and exploited to understand the different aspects that contribute to breed differentiation and to study the typical products that originate from them. The thesis is made up of three contributes. The objectives of the first one were to determine genetic variation and to analyze population structure in six Italian local chicken breeds involved in a conservation program. Twenty microsatellite markers were investigated in 337 animals belonging to six breeds: Ermellinata di Rovigo, Robusta Maculata, Robusta Lionata, Pepoi, Padovana and Polverara; a commercial layer cross was used as reference. One-hundred-twelve alleles were detected in the overall population, with a mean number of 5.6 ± 2.1 alleles per locus. For the local breeds, the observed and expected heterozigosity ranged from a minimum of 0.240 to a maximum of 0.413 and from 0.243 to 0.463 for the Pépoi and Polverara breeds, respectively. Deviation from Hardy-Weinberg equilibrium has been observed in five breeds and in the commercial cross. The overall population heterozygote deficiency FIT, resulted 0.427, the average FIS 0.097, while FST was 0.437, indicating a high heterozygote deficiency mainly due to breed subdivisions. Reynolds distances were used to draw an unrooted Neighbor-Joining tree, which topology gave information on the genetic origin of these breeds and confirmed their known history. The estimated molecular kinship within breed ranged from 0.559 to 0.769, evidencing high coancestry. Structure analysis was performed to detect the presence of population substructures. Inferred clusters corresponded to the different breeds, without presence of admixture. Exception was the Polverara, for which a more complex genetic structure was found. Obtained results confirmed the usefulness of molecular markers, as microsatellites, to characterize local breeds and to monitor genetic diversity in livestock conservation schemes. The objective of the second contribute was to describe carcass characteristics and qualitative meat traits of three local chicken breeds showing, at maturity, light, medium-light, and medium live weights. By the fact, those breeds could permit to extend and diversify consumer’s offer to fit all the local demands in typical diversified poultry products. The experiment involved 60 male chickens reared in an organic production system where housing was an indoor pen with access to a grass paddock was carried out in order to investigate carcass characteristics and qualitative meat traits of three slow-growing Italian local breeds of chicken (Ermellinata, Padovana, and Pépoi). Chicks were randomly selected at hatch, raised together under the same conditions, slaughtered at 190 days of age, dissected for carcass traits and meat was stored for subsequent analysis of breast and thigh meat quality. Ermellinata chickens were consistently heavier than Padovana and Pépoi chickens for live, carcass, thigh weight and there were differences among breeds for protein percentage (Ermellinata > Pépoi and Padovana), shear force (Padovana < Ermellinata and Pépoi), and cooking loss (Pépoi > Padovana and Ermellinata). The CIE system values of lightness (L*), redness (a*), and yellowness (b*) evidenced a distinctive darker and lighter colour of Padovana for meat and skin, respectively. Fatty acid composition of breast was similar among the studied breeds, while saturated and monounsaturated fatty acids contents of Ermellinata were higher and lower, respectively than the other breeds. Aim of the third study was to apply a proteomic approach for characterization of local chicken breeds. The experiment involved a total of 29 males of Pépoi, Padovana, and Ermellinata local chicken breeds. Samples were taken from breast muscle (Pectoralis superficialis). Sarcoplasmic protein fractions of breast muscle were analysed by bidimensional electrophoresis. Image analysis followed by statistical analysis enabled to differentiate groups of individuals on the similarities of protein expression. Individuals were distinguished into clusters and groups, corresponding to the breed of origin. SAM analysis enabled identification of the most relevant spots; 10 of these were identified by Mass Spectrometry revealing preliminary evidences on the mechanics of the breed differentiation process. Results evidenced a possible utilisation of proteomic approach in the field of breed characterization studies as an alternative to genomic analyses performed using molecular markers, both for breed and product traceability purposes.
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