Genetic Analysis of the Mitochondrial DNA Displacement Loop Region in Japanese Black Cattle

Abstract

To distinguish Japanese Black (JB) cattle from the primary crossbreed of JB and Holstein (HS) cattle, we determined partial nucleotide sequences of the mitochondrial control (D-loop) region in 6 head of JB and one head of HS cattle. JB sequences, divided into 3 groups based on the 9 nucleotide substitutions found in the 481 base-pair JB sequences differed from HS sequences. A restriction fragment-length polymorphism analysis of 36 samples suggested that the nucleotide substitutions (G to A) at the 156 and 365 positions found in 4 of 6 JB but in no HS are not unique to the JB breed. A polymerase chain reaction with a newly designed primerpair produced highly effective amplification, suggesting that the primer-pair is useful for genetic analysis of the D-loop region in cattle.