Genotyping of beta-casein, kappa-casein and beta-lactoglobulin genes in turkish native cattle breeds and efforts to delineate BCM-7 on human PBMC

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Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Biyolojik Bilimler Bölümü, Türkiye

Tezin Onay Tarihi: 2009

Öğrenci: HAVVA DİNÇ

Danışman: İNCİ ZEHRA TOGAN

Özet:

The main aim of this study is to determine genetic diversity of milk protein genes associated with milk traits, namely beta-casein, kappa-casein and betalactoglobulin, in native Turkish cattle breeds (Turkish Grey, Eastern Anatolian Red, Anatolian Black, and Southern Anatolian Red) and Turkish Holstein. Only 11% deviation from the Hardy-Weinberg equilibrium and insignificant Fis values for the populations were observed, indicating that samples are free of inbreeding. B alleles of these genes, which are positively related with cheese yield and quality, seem to be relatively high in native Turkish breeds. Therefore, the results suggest that milk of Turkish native breeds is advantageous for producing high-quality and -yield cheese. A1 allele of beta-casein, which releases a bioactive peptide called BCM-7 after successive gastrointestinal proteolytic digestions, has been claimed to have adverse health effects on humans. Another aim of this study is to develop a protocol and assess the potential detrimental effects of BCM-7 on human peripheral blood cells. Despite the fact that the results are inconclusive, the optimized experimental protocol will guide further researchers while judging the effect of BCM-7 on human health. Even though A1 beta-casein, which has a low frequency in native Turkish breeds, and hence BCM-7 have no adverse health effects on humans, this probability should be enough to keep its frequency low in native cattle breeds. Bulls must be screened for A1 allele of beta-casein as well as E allele of kappa-casein, which is absent in native breeds and known to have detrimental effects on cheese quality.