Genomic analysis of cattle rob(1;29).

Robertsonian translocation (rob) involving chromosomes 1 and 29 represents the most frequent chromosome abnormality observed in cattle breeds intended for meat production. The negative effects of this anomaly on fertility are widely demonstrated, and in many countries, screening programs are being carried out to eliminate carriers from reproduction. Although rob(1;29) was first observed in 1964, the genomic structure of this anomaly is partially unclear. In this work, we demonstrate that, during the fusion process, around 5.4 Mb of the pericentromeric region of BTA29 moves to the q arm, close to the centromere, of rob(1;29). We also clearly show that this fragment is inverted. We find that no deletion/duplication involving sequences reported in the BosTau6 genome assembly occurred during the fusion process which originates this translocation.