Comparison of the BBU1 RH map, the latest cytogenetic map and the alignment with the BTA1 and BTA27 sequence assembly (Btau_4.0). The BBU1 RH map is shown in the centre, the G-banded ideogram on the left and the corresponding cattle chromosomes on the right. The distances in cR5000 and Mbp are shown below each corresponding map. Considering the large number of mapped markers, only one marker per 50 cR is shown in the RH map. The BTA1 and BTA27 sequence maps shows one marker every 10 Mbp. Markers common to both BBU RH and the cattle sequence are joined by a solid black line or a solid red line. Solid red lines indicate markers which are oriented sequentially regarding the cattle but inverted. A solid black line also joins those markers on the BBU RH map that have been physically mapped by FISH to their location on the ideogram (Di Meo et al. 2008).