Romanian Biotechnological Letters Vol. 15, No. 1, 2010 Copyright © 2010 University of Bucharest Printed in Romania. All rights reserved ORIGINAL PAPER 5059 Genetic diversity using microsatellite markers in four Romanian autochthonous sheep breeds Received for publication, July 20, 2009 Accepted, February 15, 2010 STELIANA ELVIRA MARIA KEVORKIAN 1 , S. E. GEORGESCU 1 , MARIA ADINA MANEA 1 , MIHAELA ZAULET 1 , ANCA OANA HERMENEAN 2 , MARIETA COSTACHE 1 1.University of Bucharest, Department of Biochemistry and Molecular Biology, Spl. Independetei 91-95, Bucharest, Romania, stelyana2004@yahoo.com, marietacostache@yahoo.com 2. Vasile Goldis Western University of Arad, Arad, Romania Abstract Investigation of genetic relationship among populations was traditionally based on the analysis of allele frequencies at different loci. The four Romanian sheep breeds we have analyzed in this study are very important from an economical point of view, as they are raised for milk, meat and pelts. The aim of this study was to analyze, the genetic diversity and variability of four autochthonous Romanian sheep breeds (Botosani Karakul, Karabash, Palas Milk Line and Palas Meat Line) through the use of 11 ovine-specific microsatellite markers,. The microsatellite analysis revealed high allelic and gene diversity in all four breeds. Botosani Karakul breed showed the highest mean number of alleles (11. 6), while the highest value for polymorphic information content was observed for Palas Milk Line breed (0.83). The genetic differentiation among breeds was low, but significant (F ST =0.082) and highlighted breed differentiation. Genetic distance estimates and phylogeny analysis highlights genetic differentiation between Botosani Karakul and Karabash breeds and the two synthetic lines. Keywords: sheep, microsatellites, polymorphism, diversity. Introduction The need to maintain and improve local genetic resources has been recognized as a priority, at the European level. The maintenance of genetic diversity in livestock species requires the adequate implementation of conservation priorities and sustainable management programs, which should be based on comprehensive information regarding the structure of the populations, including sources of genetic variability among and within breeds. In Romania there are two indigenous sheep breeds: Tsurcana and Tsigai. Both breeds are supposed to descend from the wild Ovis vignei arkar. In this study we have analyzed four domestic Romanian sheep breeds (Botosani Karakul, Karabash, Palas Milk Line and Palas Meat Line), which are farmed for milk, meat and pelts. In the out bringing off these four breeds the two indigenous breeds were used. Microsatellite markers have often been used for genetic diversity studies, because of their large number, distribution throughout the genome, high level of polymorphism, co- dominant inheritance, neutrality with respect to selection and easy automation of analytical procedures (CANON & al. 2001 [1]). Microsatellite markers have been shown to be useful tools for the analysis of genetic differentiation among sheep populations as well as aids in conservation decisions for genetic resources (ARRANZ & al, 2001 [2] RENDO & al., 2004