Diacylglycerol Acyltransferase Enzimini Kodlayan DGAT1 Genindeki K232A Mutant Allelinin Saptanması

DGAT1 geni triacylglycerol (trigliserid) sentezinde önemli bir rol oynayan Diacylglycerol acyltransferase enzimini kodlamaktadır. DGAT1 sığırlarda 14. kromozomunun sentromerik bölgesinde yer alan, sütteki yağ oranını arttırmasına neden olduğu bilinen bir kantitatif özellik lokusudur (QTL). 232. aminoasit bölgesinde bir lizin aminoasidinin alanine dönüştüğü nokta RFLP ile tespit edilmiştir. Bu çalışmanın amacı İstanbul Üniversitesi Veteriner Fakültesi Eğitim, Araştırma ve Uygulama Çiftliğine ait olan İsviçre Esmeri ve Holştayn sığır ırklarında K232A mutasyonu ile K ve A allellerinin frekansını saptamaktır. KK, KA ve AA genotiplerinin ayırt edilmesinde CfrI enzimi kullanılmıştır. DNA bantları %2’lik agaroz jel elektroforezinde görüntülenmiştir. İncelenen Holştayn ve İsviçre Esmeri sığır ırklarında K ve A allellerinin frekansları sırasıyla 0.287 ve 0.713 ile 0.091 ve 0.901 olarak bulunmuştur. Bu araştırma makalesi Türkiye’deki diğer sığır ırklarında DGAT1 K ve A allellerinin frekanslarını saptamaya yönelik bir ön çalışma niteliği taşımaktadır.

Anahtar Kelimeler:

DGAT1, Holştayn, İsviçre Esmeri, RFLP

Identification of K232A mutant allele of DGAT1 Gene Encoding Diacylglycerol Acyltransferase Enzyme

DGAT1 gene encodes Diacylglycerol acyltransferase enzyme that plays a key role in triacylglycerol (triglyceride) synthesis. DGAT1 is a quantitative trait locus (QTL) that has an effect on increasing milk fat content in the centromeric region of bovine chromosome 14. Lysine (K)→Alanin (A) mutation that resulted in AA genotypes decreases milk fat rate and increases milk yield. The substitution of lysine amino acid to alanin at position 232 was identified with CfrI enzyme. The aim of this study was to identify both K232A mutation and the frequency of K and A alleles among Brown Swiss and Holstein cattle breeds which belong to Education Research and Application Farm of Istanbul University Veterinary Faculty. RFLP was used to distinguish KK, KA and AA genotypes. PCR products were screened by 2% agarose gel electrophoresis. K allele and A allele frequencies among 54 Holstein and 44 Brown Swiss cattle breeds were 0.287 and 0.713, 0.091 and 0.901 respectively. This research article constitutes the pre-study of frequency determination of DGAT1 K and A alleles in Turkish native cattle breeds.

Keywords:

Brown Swiss DGAT1, Diacylglycerol acyltransferase, Holstein, RFLP,

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