Segregation of KIT compared with segregation of the white spotting phenotype. Segregation of KIT was followed by detection of a simple-sequence repeat polymorphic difference between the Newfoundland and Border Collie grandparents. BC, DNA from the Border Collie grandparent; N, DNA from the Newfoundland grandparent; F1, DNA from the first generation hybrids; F2, DNA from the second generation intercrosses. s, white spotted; ns, not white spotted. The presumed genotypes for the KIT locus are shown below the lanes.