Existence of minute fragment and its elimination at the next generation in heritable Robertsonian translocation (1/21) from the Holstein cattle

A minute fragment was found in the metaphase plates with Robertsonian translocation (1/21) from one Holstein bull. This minute fragment disappeared in progenies composing of 5 daughter cows with the same translocation as the bull and a son bull and 4 daughter cows without translocation. The minute fragment and translocated chromosome could neither be observed in the metaphases from 5 half-sibs of the bull by different mother cows. Experimental blood cultures with BrdU showed the gradual elimination of minute fragment through the cell cycle in the bull. These results suggest that the minute fragment will be simultaneously formed at the time of formation of centric fusion (Robertsonian translocation) in the bull de novo, and eliminated at the next generation because of its small amount of centromere