Fig. 14. Linkage analysis. In this figure, all symbols are arbitrarily filled in; the affection status is not shown. Each person in the pedigree is numbered within the symbols to correspond with the gel lane containing his or her DNA sample. Each person has two bands with this marker: one band inherited from the father, the other from the mother. Bands are numbered from 1 to 5 starting with the band nearest the top of the gel. Each person's banding pattern is printed under his or her symbol. Now the paternal origin of each band can be determined for all of the children in generation II. For example, person 3 received band No. 5 from her father and band No. 4 from her mother. Person 4 received band No. 5 from her father and band No. 3 from her mother. We know this even though both parents carry band No. 3 because band No. 5 can come only from the father. Each parent contributes one band, therefore band No. 3 is maternal. (Courtesy of Edwin Stone, MD, PhD, University of Iowa)