SWINE CENTROMERIC DNA REPEATS REVEALED BY PRIMED IN-SITU (PRINS) LABELING

In swine, distinct centromeric satellite DNA families have been descri bed that correspond to either all the metacentric chromosomes except t he Y (Mc1) or all the acrocentric chromosomes (Ac2). Using primed in s itu (PRINS) labeling, we show here that primers derived from various s equences specifically label the centromeres of different subgroups of chromosomes. Among five primers derived from centromeric sequences of acrocentric chromosomes reported to be very homogeneous, four recogniz e all the acrocentric chromosomes, whereas one labels prominently chro mosome 17. For the metacentric chromosomes, six primers have been deri ved from several divergent sequences. Among these primers, two recogni ze all the metacentric chromosomes except 5, 10, and 12. Three other p rimers label small subsets of metacentric chromosomes, including the X and one or two additional chromosomes. The last primer is specific to chromosome 1. These preliminary results suggest that it should be pos sible to define specific primers for almost every swine chromosome. Al ready, some of the primers reported here permit a distinction between swine chromosomes difficult to differentiate without banding, such as the X chromosome and chromosome 9. Therefore, the PRINS technique usin g centromeric motifs constitutes an additional tool for cytogenetic st udies in swine.