Fish- Mapping and Standard GTG-Banding Karyotype of Three Egyptian Sheep Breeds

StandardizedkaryotypingbyGTG-bandingtechniqueandphysicalchromosome mapping by Fluorescentin Situ Hybridization (FISH) wereutilized to characterize the three Egyptian breeds of sheep (Barki, Rahmaniand Ossimi). Blood samples were collected from 15 individuals from eachbreed of sheep. G-banded chromosomes revealed that the karyotypemacrostructure was highly conserved and in considerable accordance to thestandard karyotype of theOvis aries. The chromosome diploid number was54 (2n=54, XX / XY). The karyotype formula was 2n, 54 = Lm6 + Ma22 + Sa24+ sex chromosomes. Physical chromosome mapping of the three breeds(Barki, Rahmani and Ossimi) was carried out by localization of twosubtelomeric SSR and two (SPRN) related specific sequences. The twosubtelomeric SSR sequences revealed six different loci in fivechromosomes (1p37, 1p36 and 17q26 with the EPCDV008 probe) and (2q45, 4q22 and 24q24 with the EPCDV016 probe), respectively. In addition, the two (SPRN) related specific sequences were successful in differentiating among the three breeds. The probe OriaBAC273H7hybridized to a similar locus (20q13) in breeds Rahmani and Ossimi, while,in Barki, it hybridized to a different locus (22q24). However, probeOriaBAC265G4 hybridized to three different loci (17q25, 22q24 and20q13) in Barki, Rahmani and Ossimi, respectively.