A.D. Malewa, L. Hakim, S. Maylinda, M.H. Husain
The objective of the study was to examine whether GH{divides}HaeIII gen in Indonesia fat tailed sheep (Donggala and East Java sheep breeds) is polymorphic and to examine whether the GH{divides}HaeIII polymorphism associate to their birth weight, growth rate and weaning weight. Seventy genomic DNAs that consisted of 42 Donggala and 28 East Java sheep were isolated from blood sample of those animals. A fragment of GH gene, comprising of a part of intron 2, complete exon 3, complete intron 3, complete exon 4, and a part of intron 4, was amplified. The amplified product with the length of 934 bp was digested with HaeIII restriction enzymes and showed the presence of GH HaeIII polymorphism with three HaeIII genotypes (AA, BB and AB). Bands with ten restricted fragments of 277, 202, 110, 100, 94, 68, 49, 22, 8 and 4 bp were identified as genotype AA. Bands with eleven restricted fragments of 256, 202, 110, 100, 94, 68, 49, 22, 21, 8 and 4 bp were identified as genotype BB. Bands with twelve restricted fragments of 277, 256, 202, 110, 100, 94, 68, 49, 22, 21, 8 and 4 bp were genotyped with AB. Gene sequencing showed that the difference between allele A and allele B occurred was due to AG (AG-CC) to (GG-CC) transition in exon 3 of the gene at 727 base (accession no Genbank GQ452268, Gul et al 2009), or at 255 base of PCR product which results in that the site is recognized by HaeIII enzyme. Thus, the fragment of 277 was split to two fragments of 256 and 21 bp respectively. In Donggala sheep, AA and AB genotypes had the same genotype frequency of 0.357, whereas BB genotype was 0.286. In East Java sheep AA genotype is the most frequent genotype (0.464), whereas BB and AB were 0.286 and 0.250, respectively. The allele frequencies of A and B in Donggala sheep were 0.536 and 0.464, respectively, whereas those for East Java sheep were 0.589 and 0.411. The degree of heterozygosity of the GH{divides}HaeIII polymorphismsin Donggala and East Java sheep are 0.503 and 0.493, respectively. GH{divides}HaeIII polymorphism affects growth rate and weaning weight both in Donggala and East Java sheep. In Donggala sheep, AA was observed to have significantly higher growth rate than BB. AB, as a heterozygote, did not show any significant differences in growth rate compared to both homozygotes (AA and BB). In East Java sheep, AB was noticed to have significantly higher and lower growth rates than BB and AA, respectively. The pattern of relationship between GH{divides}HaeIII polymorphism and weaning weight seems to be similar to those and growth rate. Genotype AA showed significantly higher weaning weight than genotypes BB both in Donggala (11.6 kg vs 9.68 kg) and East Java (10.83 kg vs 9.37 kg) sheep. Genotype AB did not show significant differences in weaning weight compared to genotypes AA and BB both in Donggala and East Java sheep. The present study concluded that GH{divides}HaeIII polymorphism could be a genetic marker in sheep selection program for improvement of growth rate and weaning weight in Indonesia fat tailed sheep.
University of Brawijaya, Malang, Indonesia; University of Tadulako, Palu 94118, Indonesia; University of Brawijaya, Malang 65145, Indonesia; University of Tadulako, Palu 94118, Indonesia
