Assessing priorities for conservation in Tuscan cattle breeds using microsatellites

Abstract

Preservation of rare genetic stocks requires assessment of within-population genetic diversity and between-population differentiation to make inferences on their degree of uniqueness. A total of 194 Tuscan cattle (44 Calvana, 35 Chianina, 25 Garfagnina, 31 Maremmana, 31 Mucca Pisana and 28 Pontremolese) individuals were genotyped for 34 microsatellite markers. Moreover, 56 samples belonging to Argentinean Creole and Asturiana de la Montañ a cattle breeds were used as an outgroup. Genetic diversity was quantified in terms of molecular coancestry and allelic richness. STRUCTURE analyses showed that the Tuscan breeds have well-differentiated genetic backgrounds, except for the Calvana and Chianina breeds, which share the same genetic ancestry. The between-breed Nei's minimum distance (D m ) matrices showed that the pair Calvana-Chianina was less differentiated (0.049 6 0.006). The endangered Tuscan breeds (Calvana, Garfagnina, Mucca Pisana and Pontremolese) made null or negative contributions to diversity, except for the Mucca Pisana contribution to allelic richness (C T 5 1.8%). The Calvana breed made null or negative within-breed contributions (f¯W 5 0.0%; C W 5 20.4%). The Garfagnina and Pontremolese breeds made positive contributions to between-breed diversity but negative and high within-breed contributions, thus suggesting population bottleneck with allelic losses and increase of homozygosity in the population. Exclusion of the four endangered Tuscan cattle breeds did not result in losses in genetic diversity (f¯T 5 20.7%; C T 5 21.2%), whereas exclusion of the non-endangered breeds (Chianina and Maremmana) did (f¯T 5 2.1%; C T 5 3.9%); the simple exclusion of the Calvana breed from the former group led to losses in genetic diversity (f¯T 5 0.47%; C T 5 2.34%), indicating a diverse significance for this breed. We showed how quantifying both within-population diversity and between-population differentiation in terms of allelic frequencies and allelic richness provides different and complementary information on the genetic backgrounds assessed and may help to implement priorities and strategies for conservation in livestock.

The genome-wide structure of two economically important indigenous Sicilian cattle breeds1

“…The estimate of the molecular f coefficient was slightly greater than those reported by other authors for local cattle breeds and populations characterized by a reduction in their population sizes (Ginja et al, 2010;Maretto et al, 2012). Bozzi et al (2012), in a study for conservation of Tuscan cattle breeds using microsatellite markers, obtained a maximum value for the f coefficient of 0.48. The results for CIN and MOD were expected considering the reduced number of reared animals and a farming system where mating with close relatives can be quite frequent.…”

Temporal Variation in Genetic Diversity and Population Structure of Burlina Cattle Breed

“…Despite its very small population size, the mean values of Ho and He in BUR were relatively high (0.634±0.165 and 0.678±0.141, respectively). Estimates were closer to values recently obtained for other local/native breeds (Medugorac et al, 2011;Delgado et al, 2011;Acosta et al, 2012;Bozzi et al, 2012) rather than to those obtained for more widespread commercial populations (Maretto et al, 2012). These results could be explained by the fact that BUR breed has always been reared by small breeders following their own separated breeding schemes with the use of their own sires and to its late enrollment in the Italian Herd Book, therefore maintaining sufficient diversity parameters.…”

“…According to our results, using microsatellite markers, FIS was limited in the range of 0.006 (2006) to 0.108 (2005) without any temporal variation trend (Figure 1d). Molecular coancestry, which is another method to calculate within-group diversity, was 0.32 (Table 1), on average, which is limited if compared to that obtained in other local breeds (Bozzi et al, 2012). Also for fij we could not identify any particular trend ( Figure 1f) (Figure 1e).…”

Genetic relationships among Italian and Croatian Podolian cattle breeds assessed by microsatellite markers

“…The f ij values here obtained were moderate (0.252 and 0.273 for the MAM and POD breeds, respectively). The analysis of population structure showed that the MAM and POD breeds were the last to differentiate (at K ¼9; data not shown), and also, differently from Pariset et al (2010) and Bozzi et al (2012), highlighted the presence of substructures within either breeds that can be favored by the low use of artificial insemination. Our results also confirm the data of Moioli et al (2004); the authors, using a different set of microsatellite markers, found a pairwise F ST value between POD and MAM of 0.041, which is consistent with the result of the present study (0.046).…”

“…Previous studies examined only a limited number of Italian Podolian breeds when defining relationships among them (Negrini et al, 2006), or with other European Podolian populations using either microsatellite or SNP markers (Bozzi et al, 2012;Moioli et al, 2004;Pariset et al, 2010). No previous work has sought to understand relationships between IST and Italian Podolian breeds.…”