Determination of expression levels of myogenic factor 5 and 6 genes in hair, angora, honamli and kilis goat breeds

Myogenic factor 5 (Myf5) and myogenic factor 6 (Myf6) genes, which are member of myogenic regulatory factors (MRFs) family, serve as the main regulators of skeletal muscle myogenesis and these genes that regulate muscle fiber development and differentiation. Therefore, the aim of this study was to investigate the expression level of Myf5 and Myf6 genes in longissimus dorsi (LD) and semitendinosus (ST) skeletal muscles of 90-day weaning age Honamlı (n=6), Hair (n=6), Kilis (n=6) and Angora (n=6) kids. RNA was isolated from muscle samples with a commercial RNA purification kit. The purity and amount of RNA was measured using the NanoDrop™ 2000/2000c spectrophotometer and the RNA quality was checked with a 1% agarose gel. RNA was converted to cDNA using a commercial cDNA kit in a Thermal Cycler device. The Myf5 and Myf6 gene expression level in LD and ST skeletal muscles was determined by real-time quantitative polymerase chain reaction. Honamli kids had higher (P < 0.05) Myf5 gene expression level (159.8 ± 14.6 fold change) in LD muscle, while Hair kids had the lowest (P < 0.05) Myf5 gene level (42.0 ± 14.9 fold change) in LD muscle. Similarly, expression levels of Myf 5 gene in ST muscle were lower (P < 0.05) in Hair kids (57.2 ± 6.6 fold), except for Angora, than those of Honamlı (98.4 ± 9.2 fold change) and Kilis breeds (80.7 ± 6.8 fold change). In the study, the expression level of Myf 6 gene in LD muscle of Kilis kids (12.0 ± 2.9 fold change) were found lower (P < 0.05) compared to Honamlı (44.5 ± 11.3 fold), Hair (34.2 ± 7.5 fold change) and Angora ( 39.8 ± 10.1 fold change) kids. In the study, there were statistically significant differences between breed in terms of the expression level of Myf 6 gene in ST muscle, the highest (P < 0.05) Myf 6 gene expression levels were found in Honamlı and Angora kids, and the lowest (P < 0.05) gene expression levels were found in Hair and Kilis kids. The results of this study showed that Honamli kids can have higher muscle growth due to higher Myf5 and Myf6 genes expression level and this breed can be recommended for a more efficient fattening application. It also showed that Kilis kid breeds may have lower muscle growth due to low Myf6 gene expression levels. As a result, it was concluded that Turkish domestic goat breeds have Myf5 and Myf6 gene expression levels and these differences can be used to select more productive breeds for fattening practices. Keywords: Native breeds, MDF gene family, Skeletal muscle, Meat production, Kid