혈액세포의 텔로미어 함량을 이용한 소의 연령예측

Abstract

Telomeres at the end of chromosomes consist of tandem repeats of(TTAGGG)n DNA sequence and associated proteins. Telomeres have the essential functions in chromosome stability and genome integrity and are hence related to cell senescence and cancer. This study was carried out to quantify the amount of telomeric DNA and establish age prediction equations by using the quantity of telomeric DNA for cattle. Analysis of the telomere quantity of the lymphocytes was performed at different age, across breeds and between different sexes of cattle. We quantified the amount of telomeric DNA by the Q-FISH technique using the telomeric DNA probe in 460 cattle at age of 1~166 months in Korean Cattle and Holstein breeds. In results, we found that the amount of telomeric DNA decreased gradually with age. The amount of telomeric DNA of Korean Cattle was significantly higher than that of Holstein breed(P<0.01). In addition, the amount of telomeric DNA in male was significantly higher than that in female(P<0.01). Using the relationship between age and the amount of telomeric DNA in cattle, age predicting equations were established as a result of regression analysis. Because sex and breeds influenced telomeric DNA quantity, the age prediction equations were estimated separately in Korean Cattle females and Holstein females. The regression equations were Ŷ=38.102X2 －220.103X+318.309(P<0.0001, R2=0.8019) in Korean Cattle females and Ŷ=42.799X2－199.682X+242.106(P<0.0001, R2=0.8379) in Holstein females, where the X was quantity of telomeric DNA and Y was predicted age in months. These equations predicted the age of cattle with high significance and accuracy and have high R square values. Thus, it could be possible to scientifically predict the age using the above equations for Korean Cattle and Holstein females.