1Department of Cell Biology, Genetic Engineering and Biotechnology Division, National Research Centre, 12622, 33 El Bohouth St., Dokki, Giza, Egypt
2Ain Shams Center for Genetic Engineering and Biotechnology and Medical Genetics Research Center, Faculty of Medicine, Cairo, Egypt
3ACGEB (Ain Shams Centre of Genetic Engineering and Biotechnology), Faculty of Agriculture, Shubra El Khima, Cairo, Egypt
Department of Cell Biology, Genetic Engineering and Biotechnology Division, National Research Centre, 12622, 33 El Bohouth St., Dokki, Giza, Egypt
*Corresponding author's e-mail: am.darwish@nrc.sci.eg
Online published on 18 July, 2018.
The beta casein gene (CSNS2) has 12 genetic variants divided into two groups: the first group (A1, B, and G) which differ from the second group (A2, A3 C, D, E, F, H, H2 and I) where A base replaces C base, this leads to potential liberation of a bioactive peptide, β-casomorphin, upon digestion where a histidine replaces a proline at position 67. The allele specific polymerase chain reaction (AS-PCR) was evaluated to distinguish between the beta casomorphin releasing variants (A1 and B) and the non-releasing variants. The sequence analysis was used to determine these variants and confirm it in goat, sheep and cattle. The results showed that cattle carrying allele A1 either homozygous or heterozygous more than sheep and goats. The allele frequency of A1 and A2 is 0.44, 0.56 in goats, 0.43, 0.57 in sheep and 0.54, 0.46 in cattle, respectively. The sequence results reported changing of C base to A base in goat, sheep and cattle. Therefore, this study reported that goat and sheep milk was more safe than cattle milk.
AS-PCR, Cattle, Goat, Sheep, β casomorphin, β-casein gene
