VARIATION IN EXON 10 OF THE OVINE CALPAIN3 GENE AND ITS ASSOCIATION WITH GROWTH AND CARCASS TRAITS IN EGYPTIAN BARKI LAMBS

The calpain 3 (CAPN3) is a major intracellular protease encoded by CAPN3 gene and mainly expressed in skeletal muscle. This protease is necessary for normal muscle function, as mutations in CAPN3 result in increasing muscle protein degradation. Polymerase chain reaction-single strand conformational polymor-phism (PCR-SSCP) was used to identify allelic and genotypic polymorphisms in exon 10 of CAPN3 gene for 24 Egyptian Barki lambs. Associations between the identified polymorphisms and growth and carcass traits were determined. Three al-leles A, B and C were identified with fre-quency 0.79, 0.14 and 0.07, respectively. Only three genotypes were identified AA, AB and AC with frequency 0.58, 0.29 and 0.13, respectively. CAPN3 genotypes sig-nificantly affected post-weaning daily gain (P < 0.005), marketing weight (P < 0.05) and lean-meat% (P<0.05). Animals with AB genotype had higher means for post-weaning daily gain; marketing weight and lean-meat%. In contrast, ani-mals with AC genotype had the lower means for these traits. Our findings sug-gest that the polymorphisms in CAPN3 may play a role affecting growth rate and lean meat% of carcass in Egyptian Barki sheep.