Proceedings of the XLVI Italian Society of Agricultural Genetics - SIGA Annual Congress

Giardini Naxos, Italy - 18/21 September, 2002

ISBN 88-900622-3-1

Oral Communication Abstract - S4f

GENETIC CHARACTERISATION OF NINE ITALIAN SHEEP BREEDS USING A SET OF 10 MICROSATELLITE MARKERS

CAPPUCCIO I.*, PARISET L.*, SANTUCCI F.**, LAWSON L. J.**, HEWITT G.**, VALENTINI A.*

*) Dipartimento di Produzioni Animali, Università della Tuscia, Viterbo, Italy

**) School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, U. K.

sheep, microsatellite, genetic diversity, genotype assignment

Approximately 4000 breeds of domestic sheep (Ovis Aries) are recognised world wide and a significant proportion of them is found within Europe. In Italy the sheep population comprise some 50 breeds but in the 20^th century many local well adapted breeds were replaced by a few highly selected commercial breeds. Some of them are now extinct with an irredimable loss of genetic variability that was potentially useful for selection. In order to develop a strategy to preserve the biodiversity of this species, it is important to assess the extent of present genetic variation both within and between breeds. In this study, we have analyzed 15-30 individuals per breed sampled from 9 of the most representative commercial and local italian breeds with 10 microsatellite markers. We have used their allele frequencies to calculate the differences within and between breeds, to construct a Nejghbour-Joining tree showing the relationship among these breeds and finally we have used the data to assign the individuals to their breeds. The results show high levels of genetic diversity within Italian sheep breeds and a low level of genetic diversity among Italian breeds. A method based on allele frequencies allowed an assignment of individuals to the correct breed that approached 100%. The levels of genetic diversity are encouraging for the development of future conservation strategies for Italian sheep breeds.